summary refs log tree commit diff
diff options
context:
space:
mode:
-rw-r--r--.buildkite/postgres-config.yaml21
-rwxr-xr-x.buildkite/scripts/create_postgres_db.py36
-rwxr-xr-x.buildkite/scripts/test_synapse_port_db.sh36
-rw-r--r--.buildkite/sqlite-config.yaml18
-rw-r--r--.buildkite/test_db.dbbin0 -> 18825216 bytes
-rw-r--r--.github/PULL_REQUEST_TEMPLATE.md1
-rw-r--r--CONTRIBUTING.rst19
-rw-r--r--changelog.d/5727.feature1
-rw-r--r--changelog.d/6140.misc1
-rw-r--r--changelog.d/6164.doc1
-rw-r--r--changelog.d/6218.misc1
-rw-r--r--changelog.d/6232.bugfix1
-rw-r--r--changelog.d/6238.feature1
-rw-r--r--changelog.d/6240.misc1
-rw-r--r--changelog.d/6250.misc1
-rw-r--r--changelog.d/6251.misc1
-rw-r--r--changelog.d/6253.bugfix1
-rw-r--r--changelog.d/6254.bugfix1
-rw-r--r--changelog.d/6257.doc1
-rw-r--r--changelog.d/6259.misc1
-rw-r--r--changelog.d/6263.misc1
-rw-r--r--changelog.d/6269.misc1
-rw-r--r--changelog.d/6270.misc1
-rw-r--r--changelog.d/6271.misc1
-rw-r--r--changelog.d/6273.doc1
-rw-r--r--changelog.d/6274.misc1
-rw-r--r--changelog.d/6275.misc1
-rw-r--r--changelog.d/6276.misc1
-rw-r--r--changelog.d/6277.misc1
-rw-r--r--changelog.d/6278.bugfix1
-rw-r--r--changelog.d/6279.misc1
-rw-r--r--changelog.d/6280.misc1
-rw-r--r--changelog.d/6284.bugfix1
-rw-r--r--changelog.d/6291.misc1
-rw-r--r--changelog.d/6294.misc1
-rw-r--r--changelog.d/6298.misc1
-rw-r--r--changelog.d/6300.misc1
-rw-r--r--changelog.d/6301.feature1
-rw-r--r--changelog.d/6304.misc1
-rw-r--r--changelog.d/6305.misc1
-rw-r--r--changelog.d/6306.bugfix1
-rw-r--r--changelog.d/6307.bugfix1
-rw-r--r--changelog.d/6312.misc1
-rw-r--r--changelog.d/6313.bugfix1
-rw-r--r--changelog.d/6314.misc1
-rw-r--r--changelog.d/6318.misc1
-rw-r--r--changelog.d/6319.misc1
-rw-r--r--changelog.d/6320.bugfix1
-rw-r--r--changelog.d/6330.misc1
-rw-r--r--changelog.d/6336.misc1
-rw-r--r--contrib/experiments/test_messaging.py4
-rw-r--r--docker/README.md2
-rw-r--r--docs/CAPTCHA_SETUP.md6
-rw-r--r--docs/sample_config.yaml2
-rw-r--r--docs/tcp_replication.md15
-rw-r--r--mypy.ini11
-rwxr-xr-xscripts-dev/lint.sh14
-rwxr-xr-xscripts-dev/update_database124
-rwxr-xr-xscripts/move_remote_media_to_new_store.py2
-rwxr-xr-xscripts/synapse_port_db6
-rw-r--r--synapse/api/auth.py2
-rw-r--r--synapse/api/constants.py7
-rw-r--r--synapse/api/filtering.py15
-rw-r--r--synapse/app/__init__.py4
-rw-r--r--synapse/app/appservice.py4
-rw-r--r--synapse/app/client_reader.py4
-rw-r--r--synapse/app/event_creator.py4
-rw-r--r--synapse/app/federation_reader.py4
-rw-r--r--synapse/app/federation_sender.py4
-rw-r--r--synapse/app/frontend_proxy.py4
-rw-r--r--synapse/app/homeserver.py174
-rw-r--r--synapse/app/media_repository.py4
-rw-r--r--synapse/app/pusher.py4
-rw-r--r--synapse/app/synchrotron.py4
-rw-r--r--synapse/app/user_dir.py4
-rw-r--r--synapse/appservice/__init__.py4
-rw-r--r--synapse/config/key.py4
-rw-r--r--synapse/config/logger.py6
-rw-r--r--synapse/config/registration.py2
-rw-r--r--synapse/crypto/event_signing.py6
-rw-r--r--synapse/event_auth.py2
-rw-r--r--synapse/events/snapshot.py318
-rw-r--r--synapse/events/spamcheck.py14
-rw-r--r--synapse/federation/federation_base.py6
-rw-r--r--synapse/federation/federation_client.py12
-rw-r--r--synapse/federation/federation_server.py239
-rw-r--r--synapse/federation/send_queue.py4
-rw-r--r--synapse/federation/sender/per_destination_queue.py19
-rw-r--r--synapse/federation/sender/transaction_manager.py4
-rw-r--r--synapse/federation/transport/client.py4
-rw-r--r--synapse/federation/transport/server.py8
-rw-r--r--synapse/groups/attestations.py2
-rw-r--r--synapse/groups/groups_server.py2
-rw-r--r--synapse/handlers/account_data.py7
-rw-r--r--synapse/handlers/admin.py7
-rw-r--r--synapse/handlers/appservice.py5
-rw-r--r--synapse/handlers/auth.py6
-rw-r--r--synapse/handlers/device.py20
-rw-r--r--synapse/handlers/devicemessage.py2
-rw-r--r--synapse/handlers/directory.py2
-rw-r--r--synapse/handlers/e2e_keys.py174
-rw-r--r--synapse/handlers/events.py6
-rw-r--r--synapse/handlers/federation.py136
-rw-r--r--synapse/handlers/groups_local.py2
-rw-r--r--synapse/handlers/identity.py6
-rw-r--r--synapse/handlers/initial_sync.py18
-rw-r--r--synapse/handlers/message.py29
-rw-r--r--synapse/handlers/pagination.py19
-rw-r--r--synapse/handlers/profile.py2
-rw-r--r--synapse/handlers/read_marker.py13
-rw-r--r--synapse/handlers/receipts.py37
-rw-r--r--synapse/handlers/register.py4
-rw-r--r--synapse/handlers/room.py45
-rw-r--r--synapse/handlers/room_member.py116
-rw-r--r--synapse/handlers/search.py24
-rw-r--r--synapse/handlers/stats.py5
-rw-r--r--synapse/handlers/sync.py36
-rw-r--r--synapse/handlers/ui_auth/checkers.py2
-rw-r--r--synapse/http/client.py21
-rw-r--r--synapse/http/connectproxyclient.py195
-rw-r--r--synapse/http/federation/srv_resolver.py2
-rw-r--r--synapse/http/matrixfederationclient.py10
-rw-r--r--synapse/http/proxyagent.py195
-rw-r--r--synapse/http/request_metrics.py2
-rw-r--r--synapse/http/server.py2
-rw-r--r--synapse/http/servlet.py4
-rw-r--r--synapse/http/site.py4
-rw-r--r--synapse/logging/_structured.py2
-rw-r--r--synapse/logging/context.py2
-rw-r--r--synapse/notifier.py6
-rw-r--r--synapse/push/bulk_push_rule_evaluator.py9
-rw-r--r--synapse/push/emailpusher.py14
-rw-r--r--synapse/push/httppusher.py23
-rw-r--r--synapse/push/mailer.py3
-rw-r--r--synapse/push/push_rule_evaluator.py4
-rw-r--r--synapse/push/push_tools.py9
-rw-r--r--synapse/push/pusherpool.py4
-rw-r--r--synapse/python_dependencies.py1
-rw-r--r--synapse/replication/http/_base.py8
-rw-r--r--synapse/replication/http/federation.py24
-rw-r--r--synapse/replication/http/login.py7
-rw-r--r--synapse/replication/http/membership.py16
-rw-r--r--synapse/replication/http/register.py12
-rw-r--r--synapse/replication/http/send_event.py7
-rw-r--r--synapse/replication/slave/storage/_base.py10
-rw-r--r--synapse/replication/slave/storage/devices.py13
-rw-r--r--synapse/replication/tcp/client.py22
-rw-r--r--synapse/replication/tcp/protocol.py76
-rw-r--r--synapse/replication/tcp/streams/__init__.py1
-rw-r--r--synapse/replication/tcp/streams/_base.py18
-rw-r--r--synapse/rest/admin/__init__.py2
-rw-r--r--synapse/rest/client/v1/login.py17
-rw-r--r--synapse/rest/client/v1/room.py166
-rw-r--r--synapse/rest/client/v2_alpha/account.py18
-rw-r--r--synapse/rest/client/v2_alpha/read_marker.py13
-rw-r--r--synapse/rest/client/v2_alpha/receipts.py11
-rw-r--r--synapse/rest/client/v2_alpha/register.py14
-rw-r--r--synapse/rest/client/v2_alpha/sync.py13
-rw-r--r--synapse/rest/client/versions.py3
-rw-r--r--synapse/rest/key/v2/remote_key_resource.py2
-rw-r--r--synapse/rest/media/v1/media_repository.py12
-rw-r--r--synapse/rest/media/v1/preview_url_resource.py30
-rw-r--r--synapse/rest/media/v1/thumbnail_resource.py4
-rw-r--r--synapse/server.py23
-rw-r--r--synapse/server.pyi25
-rw-r--r--synapse/server_notices/resource_limits_server_notices.py2
-rw-r--r--synapse/spam_checker_api/__init__.py51
-rw-r--r--synapse/state/__init__.py182
-rw-r--r--synapse/storage/__init__.py21
-rw-r--r--synapse/storage/_base.py6
-rw-r--r--synapse/storage/background_updates.py9
-rw-r--r--synapse/storage/data_stores/__init__.py12
-rw-r--r--synapse/storage/data_stores/main/__init__.py9
-rw-r--r--synapse/storage/data_stores/main/devices.py109
-rw-r--r--synapse/storage/data_stores/main/e2e_room_keys.py8
-rw-r--r--synapse/storage/data_stores/main/end_to_end_keys.py24
-rw-r--r--synapse/storage/data_stores/main/event_federation.py4
-rw-r--r--synapse/storage/data_stores/main/event_push_actions.py2
-rw-r--r--synapse/storage/data_stores/main/events.py774
-rw-r--r--synapse/storage/data_stores/main/events_bg_updates.py2
-rw-r--r--synapse/storage/data_stores/main/group_server.py4
-rw-r--r--synapse/storage/data_stores/main/monthly_active_users.py2
-rw-r--r--synapse/storage/data_stores/main/push_rule.py2
-rw-r--r--synapse/storage/data_stores/main/pusher.py2
-rw-r--r--synapse/storage/data_stores/main/registration.py2
-rw-r--r--synapse/storage/data_stores/main/roommember.py4
-rw-r--r--synapse/storage/data_stores/main/schema/delta/56/delete_keys_from_deleted_backups.sql25
-rw-r--r--synapse/storage/data_stores/main/schema/delta/56/event_labels.sql30
-rw-r--r--synapse/storage/data_stores/main/schema/delta/56/hidden_devices_fix.sql.sqlite42
-rw-r--r--synapse/storage/data_stores/main/search.py4
-rw-r--r--synapse/storage/data_stores/main/state.py29
-rw-r--r--synapse/storage/data_stores/main/stats.py6
-rw-r--r--synapse/storage/data_stores/main/stream.py11
-rw-r--r--synapse/storage/persist_events.py649
-rw-r--r--synapse/storage/state.py233
-rw-r--r--synapse/storage/util/id_generators.py2
-rw-r--r--synapse/util/async_helpers.py18
-rw-r--r--synapse/util/caches/__init__.py2
-rw-r--r--synapse/util/caches/descriptors.py9
-rw-r--r--synapse/util/metrics.py6
-rw-r--r--synapse/util/rlimit.py2
-rw-r--r--synapse/util/versionstring.py10
-rw-r--r--synapse/visibility.py30
-rw-r--r--tests/api/test_filtering.py43
-rw-r--r--tests/crypto/test_keyring.py4
-rw-r--r--tests/handlers/test_federation.py126
-rw-r--r--tests/handlers/test_typing.py7
-rw-r--r--tests/http/__init__.py17
-rw-r--r--tests/http/federation/test_matrix_federation_agent.py11
-rw-r--r--tests/http/test_proxyagent.py334
-rw-r--r--tests/push/test_http.py2
-rw-r--r--tests/replication/slave/storage/_base.py1
-rw-r--r--tests/replication/slave/storage/test_events.py10
-rw-r--r--tests/rest/admin/test_admin.py78
-rw-r--r--tests/rest/client/v1/test_rooms.py101
-rw-r--r--tests/rest/client/v1/utils.py15
-rw-r--r--tests/rest/client/v2_alpha/test_sync.py143
-rw-r--r--tests/server.py30
-rw-r--r--tests/storage/test__base.py2
-rw-r--r--tests/storage/test_devices.py16
-rw-r--r--tests/storage/test_e2e_room_keys.py75
-rw-r--r--tests/storage/test_redaction.py11
-rw-r--r--tests/storage/test_room.py3
-rw-r--r--tests/storage/test_roommember.py3
-rw-r--r--tests/storage/test_state.py153
-rw-r--r--tests/test_federation.py15
-rw-r--r--tests/test_phone_home.py51
-rw-r--r--tests/test_state.py64
-rw-r--r--tests/test_visibility.py18
-rw-r--r--tests/util/caches/test_descriptors.py8
-rw-r--r--tests/utils.py10
-rw-r--r--tox.ini8
232 files changed, 4843 insertions, 1915 deletions
diff --git a/.buildkite/postgres-config.yaml b/.buildkite/postgres-config.yaml
new file mode 100644
index 0000000000..a35fec394d
--- /dev/null
+++ b/.buildkite/postgres-config.yaml
@@ -0,0 +1,21 @@
+# Configuration file used for testing the 'synapse_port_db' script.
+# Tells the script to connect to the postgresql database that will be available in the
+# CI's Docker setup at the point where this file is considered.
+server_name: "test"
+
+signing_key_path: "/src/.buildkite/test.signing.key"
+
+report_stats: false
+
+database:
+  name: "psycopg2"
+  args:
+    user: postgres
+    host: postgres
+    password: postgres
+    database: synapse
+
+# Suppress the key server warning.
+trusted_key_servers:
+  - server_name: "matrix.org"
+suppress_key_server_warning: true
diff --git a/.buildkite/scripts/create_postgres_db.py b/.buildkite/scripts/create_postgres_db.py
new file mode 100755
index 0000000000..df6082b0ac
--- /dev/null
+++ b/.buildkite/scripts/create_postgres_db.py
@@ -0,0 +1,36 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+# Copyright 2019 The Matrix.org Foundation C.I.C.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import logging
+from synapse.storage.engines import create_engine
+
+logger = logging.getLogger("create_postgres_db")
+
+if __name__ == "__main__":
+    # Create a PostgresEngine.
+    db_engine = create_engine({"name": "psycopg2", "args": {}})
+
+    # Connect to postgres to create the base database.
+    # We use "postgres" as a database because it's bound to exist and the "synapse" one
+    # doesn't exist yet.
+    db_conn = db_engine.module.connect(
+        user="postgres", host="postgres", password="postgres", dbname="postgres"
+    )
+    db_conn.autocommit = True
+    cur = db_conn.cursor()
+    cur.execute("CREATE DATABASE synapse;")
+    cur.close()
+    db_conn.close()
diff --git a/.buildkite/scripts/test_synapse_port_db.sh b/.buildkite/scripts/test_synapse_port_db.sh
new file mode 100755
index 0000000000..9ed2177635
--- /dev/null
+++ b/.buildkite/scripts/test_synapse_port_db.sh
@@ -0,0 +1,36 @@
+#!/bin/bash
+#
+# Test script for 'synapse_port_db', which creates a virtualenv, installs Synapse along
+# with additional dependencies needed for the test (such as coverage or the PostgreSQL
+# driver), update the schema of the test SQLite database and run background updates on it,
+# create an empty test database in PostgreSQL, then run the 'synapse_port_db' script to
+# test porting the SQLite database to the PostgreSQL database (with coverage).
+
+set -xe
+cd `dirname $0`/../..
+
+echo "--- Install dependencies"
+
+# Install dependencies for this test.
+pip install psycopg2 coverage coverage-enable-subprocess
+
+# Install Synapse itself. This won't update any libraries.
+pip install -e .
+
+echo "--- Generate the signing key"
+
+# Generate the server's signing key.
+python -m synapse.app.homeserver --generate-keys -c .buildkite/sqlite-config.yaml
+
+echo "--- Prepare the databases"
+
+# Make sure the SQLite3 database is using the latest schema and has no pending background update.
+scripts-dev/update_database --database-config .buildkite/sqlite-config.yaml
+
+# Create the PostgreSQL database.
+./.buildkite/scripts/create_postgres_db.py
+
+echo "+++ Run synapse_port_db"
+
+# Run the script
+coverage run scripts/synapse_port_db --sqlite-database .buildkite/test_db.db --postgres-config .buildkite/postgres-config.yaml
diff --git a/.buildkite/sqlite-config.yaml b/.buildkite/sqlite-config.yaml
new file mode 100644
index 0000000000..635b921764
--- /dev/null
+++ b/.buildkite/sqlite-config.yaml
@@ -0,0 +1,18 @@
+# Configuration file used for testing the 'synapse_port_db' script.
+# Tells the 'update_database' script to connect to the test SQLite database to upgrade its
+# schema and run background updates on it.
+server_name: "test"
+
+signing_key_path: "/src/.buildkite/test.signing.key"
+
+report_stats: false
+
+database:
+  name: "sqlite3"
+  args:
+    database: ".buildkite/test_db.db"
+
+# Suppress the key server warning.
+trusted_key_servers:
+  - server_name: "matrix.org"
+suppress_key_server_warning: true
diff --git a/.buildkite/test_db.db b/.buildkite/test_db.db
new file mode 100644
index 0000000000..f20567ba73
--- /dev/null
+++ b/.buildkite/test_db.db
Binary files differdiff --git a/.github/PULL_REQUEST_TEMPLATE.md b/.github/PULL_REQUEST_TEMPLATE.md
index 1ead0d0030..8939fda67d 100644
--- a/.github/PULL_REQUEST_TEMPLATE.md
+++ b/.github/PULL_REQUEST_TEMPLATE.md
@@ -5,3 +5,4 @@
 * [ ] Pull request is based on the develop branch
 * [ ] Pull request includes a [changelog file](https://github.com/matrix-org/synapse/blob/master/CONTRIBUTING.rst#changelog)
 * [ ] Pull request includes a [sign off](https://github.com/matrix-org/synapse/blob/master/CONTRIBUTING.rst#sign-off)
+* [ ] Code style is correct (run the [linters](https://github.com/matrix-org/synapse/blob/master/CONTRIBUTING.rst#code-style))
diff --git a/CONTRIBUTING.rst b/CONTRIBUTING.rst
index a71a4a696b..df81f6e54f 100644
--- a/CONTRIBUTING.rst
+++ b/CONTRIBUTING.rst
@@ -58,10 +58,29 @@ All Matrix projects have a well-defined code-style - and sometimes we've even
 got as far as documenting it... For instance, synapse's code style doc lives
 at https://github.com/matrix-org/synapse/tree/master/docs/code_style.md.
 
+To facilitate meeting these criteria you can run ``scripts-dev/lint.sh``
+locally. Since this runs the tools listed in the above document, you'll need
+python 3.6 and to install each tool. **Note that the script does not just
+test/check, but also reformats code, so you may wish to ensure any new code is
+committed first**. By default this script checks all files and can take some
+time; if you alter only certain files, you might wish to specify paths as
+arguments to reduce the run-time.
+
 Please ensure your changes match the cosmetic style of the existing project,
 and **never** mix cosmetic and functional changes in the same commit, as it
 makes it horribly hard to review otherwise.
 
+Before doing a commit, ensure the changes you've made don't produce
+linting errors. You can do this by running the linters as follows. Ensure to
+commit any files that were corrected.
+
+::
+    # Install the dependencies
+    pip install -U black flake8 isort
+    
+    # Run the linter script
+    ./scripts-dev/lint.sh
+
 Changelog
 ~~~~~~~~~
 
diff --git a/changelog.d/5727.feature b/changelog.d/5727.feature
new file mode 100644
index 0000000000..819bebf2d7
--- /dev/null
+++ b/changelog.d/5727.feature
@@ -0,0 +1 @@
+Add federation support for cross-signing.
diff --git a/changelog.d/6140.misc b/changelog.d/6140.misc
new file mode 100644
index 0000000000..0feb97ec61
--- /dev/null
+++ b/changelog.d/6140.misc
@@ -0,0 +1 @@
+Add a CI job to test the `synapse_port_db` script.
\ No newline at end of file
diff --git a/changelog.d/6164.doc b/changelog.d/6164.doc
new file mode 100644
index 0000000000..f9395b02b3
--- /dev/null
+++ b/changelog.d/6164.doc
@@ -0,0 +1 @@
+Contributor documentation now mentions script to run linters.
diff --git a/changelog.d/6218.misc b/changelog.d/6218.misc
new file mode 100644
index 0000000000..49d10c36cf
--- /dev/null
+++ b/changelog.d/6218.misc
@@ -0,0 +1 @@
+Convert EventContext to an attrs.
diff --git a/changelog.d/6232.bugfix b/changelog.d/6232.bugfix
new file mode 100644
index 0000000000..12718ba934
--- /dev/null
+++ b/changelog.d/6232.bugfix
@@ -0,0 +1 @@
+Remove a room from a server's public rooms list on room upgrade.
\ No newline at end of file
diff --git a/changelog.d/6238.feature b/changelog.d/6238.feature
new file mode 100644
index 0000000000..d225ac33b6
--- /dev/null
+++ b/changelog.d/6238.feature
@@ -0,0 +1 @@
+Add support for outbound http proxying via http_proxy/HTTPS_PROXY env vars.
diff --git a/changelog.d/6240.misc b/changelog.d/6240.misc
new file mode 100644
index 0000000000..0b3d7a14a1
--- /dev/null
+++ b/changelog.d/6240.misc
@@ -0,0 +1 @@
+Move `persist_events` out from main data store.
diff --git a/changelog.d/6250.misc b/changelog.d/6250.misc
new file mode 100644
index 0000000000..12e3fe66b0
--- /dev/null
+++ b/changelog.d/6250.misc
@@ -0,0 +1 @@
+Reduce verbosity of user/room stats.
diff --git a/changelog.d/6251.misc b/changelog.d/6251.misc
new file mode 100644
index 0000000000..371c6983be
--- /dev/null
+++ b/changelog.d/6251.misc
@@ -0,0 +1 @@
+Reduce impact of debug logging.
diff --git a/changelog.d/6253.bugfix b/changelog.d/6253.bugfix
new file mode 100644
index 0000000000..266fae381c
--- /dev/null
+++ b/changelog.d/6253.bugfix
@@ -0,0 +1 @@
+Delete keys from key backup when deleting backup versions.
diff --git a/changelog.d/6254.bugfix b/changelog.d/6254.bugfix
new file mode 100644
index 0000000000..3181484b88
--- /dev/null
+++ b/changelog.d/6254.bugfix
@@ -0,0 +1 @@
+Make notification of cross-signing signatures work with workers.
diff --git a/changelog.d/6257.doc b/changelog.d/6257.doc
new file mode 100644
index 0000000000..e985afde0e
--- /dev/null
+++ b/changelog.d/6257.doc
@@ -0,0 +1 @@
+Modify CAPTCHA_SETUP.md to update the terms `private key` and `public key` to `secret key` and `site key` respectively. Contributed by Yash Jipkate.
diff --git a/changelog.d/6259.misc b/changelog.d/6259.misc
new file mode 100644
index 0000000000..3ff81b1ac7
--- /dev/null
+++ b/changelog.d/6259.misc
@@ -0,0 +1 @@
+Expose some homeserver functionality to spam checkers.
diff --git a/changelog.d/6263.misc b/changelog.d/6263.misc
new file mode 100644
index 0000000000..7b1bb4b679
--- /dev/null
+++ b/changelog.d/6263.misc
@@ -0,0 +1 @@
+Change cache descriptors to always return deferreds.
diff --git a/changelog.d/6269.misc b/changelog.d/6269.misc
new file mode 100644
index 0000000000..9fd333cc89
--- /dev/null
+++ b/changelog.d/6269.misc
@@ -0,0 +1 @@
+Fix incorrect comment regarding the functionality of an `if` statement.
\ No newline at end of file
diff --git a/changelog.d/6270.misc b/changelog.d/6270.misc
new file mode 100644
index 0000000000..d1c5811323
--- /dev/null
+++ b/changelog.d/6270.misc
@@ -0,0 +1 @@
+Update CI to run `isort` over the `scripts` and `scripts-dev` directories.
\ No newline at end of file
diff --git a/changelog.d/6271.misc b/changelog.d/6271.misc
new file mode 100644
index 0000000000..2369760272
--- /dev/null
+++ b/changelog.d/6271.misc
@@ -0,0 +1 @@
+Replace every instance of `logger.warn` method with `logger.warning` as the former is deprecated.
\ No newline at end of file
diff --git a/changelog.d/6273.doc b/changelog.d/6273.doc
new file mode 100644
index 0000000000..21a41d987d
--- /dev/null
+++ b/changelog.d/6273.doc
@@ -0,0 +1 @@
+Fix a small typo in `account_threepid_delegates` configuration option.
\ No newline at end of file
diff --git a/changelog.d/6274.misc b/changelog.d/6274.misc
new file mode 100644
index 0000000000..eb4966124f
--- /dev/null
+++ b/changelog.d/6274.misc
@@ -0,0 +1 @@
+Port replication http server endpoints to async/await.
diff --git a/changelog.d/6275.misc b/changelog.d/6275.misc
new file mode 100644
index 0000000000..f57e2c4adb
--- /dev/null
+++ b/changelog.d/6275.misc
@@ -0,0 +1 @@
+Port room rest handlers to async/await.
diff --git a/changelog.d/6276.misc b/changelog.d/6276.misc
new file mode 100644
index 0000000000..4a4428251e
--- /dev/null
+++ b/changelog.d/6276.misc
@@ -0,0 +1 @@
+Add a CI job to test the `synapse_port_db` script.
diff --git a/changelog.d/6277.misc b/changelog.d/6277.misc
new file mode 100644
index 0000000000..490713577f
--- /dev/null
+++ b/changelog.d/6277.misc
@@ -0,0 +1 @@
+Remove redundant CLI parameters on CI's `flake8` step.
\ No newline at end of file
diff --git a/changelog.d/6278.bugfix b/changelog.d/6278.bugfix
new file mode 100644
index 0000000000..c107270461
--- /dev/null
+++ b/changelog.d/6278.bugfix
@@ -0,0 +1 @@
+Fix exception when remote servers attempt to join a room that they're not allowed to join.
diff --git a/changelog.d/6279.misc b/changelog.d/6279.misc
new file mode 100644
index 0000000000..5f5144a9ee
--- /dev/null
+++ b/changelog.d/6279.misc
@@ -0,0 +1 @@
+Port `federation_server.py` to async/await.
diff --git a/changelog.d/6280.misc b/changelog.d/6280.misc
new file mode 100644
index 0000000000..96a0eb21b2
--- /dev/null
+++ b/changelog.d/6280.misc
@@ -0,0 +1 @@
+Port receipt and read markers to async/wait.
diff --git a/changelog.d/6284.bugfix b/changelog.d/6284.bugfix
new file mode 100644
index 0000000000..cf15053d2d
--- /dev/null
+++ b/changelog.d/6284.bugfix
@@ -0,0 +1 @@
+Prevent errors from appearing on Synapse startup if `git` is not installed.
\ No newline at end of file
diff --git a/changelog.d/6291.misc b/changelog.d/6291.misc
new file mode 100644
index 0000000000..7b1bb4b679
--- /dev/null
+++ b/changelog.d/6291.misc
@@ -0,0 +1 @@
+Change cache descriptors to always return deferreds.
diff --git a/changelog.d/6294.misc b/changelog.d/6294.misc
new file mode 100644
index 0000000000..a3e6b8296e
--- /dev/null
+++ b/changelog.d/6294.misc
@@ -0,0 +1 @@
+Split out state storage into separate data store.
diff --git a/changelog.d/6298.misc b/changelog.d/6298.misc
new file mode 100644
index 0000000000..d4190730b2
--- /dev/null
+++ b/changelog.d/6298.misc
@@ -0,0 +1 @@
+Refactor EventContext for clarity.
\ No newline at end of file
diff --git a/changelog.d/6300.misc b/changelog.d/6300.misc
new file mode 100644
index 0000000000..0b3d7a14a1
--- /dev/null
+++ b/changelog.d/6300.misc
@@ -0,0 +1 @@
+Move `persist_events` out from main data store.
diff --git a/changelog.d/6301.feature b/changelog.d/6301.feature
new file mode 100644
index 0000000000..78a187a1dc
--- /dev/null
+++ b/changelog.d/6301.feature
@@ -0,0 +1 @@
+Implement label-based filtering on `/sync` and `/messages` ([MSC2326](https://github.com/matrix-org/matrix-doc/pull/2326)).
diff --git a/changelog.d/6304.misc b/changelog.d/6304.misc
new file mode 100644
index 0000000000..20372b4f7c
--- /dev/null
+++ b/changelog.d/6304.misc
@@ -0,0 +1 @@
+Update the version of black used to 19.10b0.
diff --git a/changelog.d/6305.misc b/changelog.d/6305.misc
new file mode 100644
index 0000000000..f047fc3062
--- /dev/null
+++ b/changelog.d/6305.misc
@@ -0,0 +1 @@
+Add some documentation about worker replication.
diff --git a/changelog.d/6306.bugfix b/changelog.d/6306.bugfix
new file mode 100644
index 0000000000..c7dcbcdce8
--- /dev/null
+++ b/changelog.d/6306.bugfix
@@ -0,0 +1 @@
+Appservice requests will no longer contain a double slash prefix when the appservice url provided ends in a slash.
diff --git a/changelog.d/6307.bugfix b/changelog.d/6307.bugfix
new file mode 100644
index 0000000000..f2917c5053
--- /dev/null
+++ b/changelog.d/6307.bugfix
@@ -0,0 +1 @@
+Fix `/purge_room` admin API.
diff --git a/changelog.d/6312.misc b/changelog.d/6312.misc
new file mode 100644
index 0000000000..55e3e1654d
--- /dev/null
+++ b/changelog.d/6312.misc
@@ -0,0 +1 @@
+Document the use of `lint.sh` for code style enforcement & extend it to run on specified paths only.
diff --git a/changelog.d/6313.bugfix b/changelog.d/6313.bugfix
new file mode 100644
index 0000000000..f4d4a97f00
--- /dev/null
+++ b/changelog.d/6313.bugfix
@@ -0,0 +1 @@
+Fix the `hidden` field in the `devices` table for SQLite versions prior to 3.23.0.
diff --git a/changelog.d/6314.misc b/changelog.d/6314.misc
new file mode 100644
index 0000000000..2369760272
--- /dev/null
+++ b/changelog.d/6314.misc
@@ -0,0 +1 @@
+Replace every instance of `logger.warn` method with `logger.warning` as the former is deprecated.
\ No newline at end of file
diff --git a/changelog.d/6318.misc b/changelog.d/6318.misc
new file mode 100644
index 0000000000..63527ccef4
--- /dev/null
+++ b/changelog.d/6318.misc
@@ -0,0 +1 @@
+Remove the dependency on psutil and replace functionality with the stdlib `resource` module.
diff --git a/changelog.d/6319.misc b/changelog.d/6319.misc
new file mode 100644
index 0000000000..9711ef21ed
--- /dev/null
+++ b/changelog.d/6319.misc
@@ -0,0 +1 @@
+Improve documentation for EventContext fields.
diff --git a/changelog.d/6320.bugfix b/changelog.d/6320.bugfix
new file mode 100644
index 0000000000..2c3fad5655
--- /dev/null
+++ b/changelog.d/6320.bugfix
@@ -0,0 +1 @@
+Fix bug which casued rejected events to be persisted with the wrong room state.
diff --git a/changelog.d/6330.misc b/changelog.d/6330.misc
new file mode 100644
index 0000000000..6239cba263
--- /dev/null
+++ b/changelog.d/6330.misc
@@ -0,0 +1 @@
+Add some checks that we aren't using state from rejected events.
diff --git a/changelog.d/6336.misc b/changelog.d/6336.misc
new file mode 100644
index 0000000000..63527ccef4
--- /dev/null
+++ b/changelog.d/6336.misc
@@ -0,0 +1 @@
+Remove the dependency on psutil and replace functionality with the stdlib `resource` module.
diff --git a/contrib/experiments/test_messaging.py b/contrib/experiments/test_messaging.py
index 6b22400a60..3bbbcfa1b4 100644
--- a/contrib/experiments/test_messaging.py
+++ b/contrib/experiments/test_messaging.py
@@ -78,7 +78,7 @@ class InputOutput(object):
             m = re.match("^join (\S+)$", line)
             if m:
                 # The `sender` wants to join a room.
-                room_name, = m.groups()
+                (room_name,) = m.groups()
                 self.print_line("%s joining %s" % (self.user, room_name))
                 self.server.join_room(room_name, self.user, self.user)
                 # self.print_line("OK.")
@@ -105,7 +105,7 @@ class InputOutput(object):
             m = re.match("^backfill (\S+)$", line)
             if m:
                 # we want to backfill a room
-                room_name, = m.groups()
+                (room_name,) = m.groups()
                 self.print_line("backfill %s" % room_name)
                 self.server.backfill(room_name)
                 return
diff --git a/docker/README.md b/docker/README.md
index 4b712f3f5c..24dfa77dcc 100644
--- a/docker/README.md
+++ b/docker/README.md
@@ -101,7 +101,7 @@ is suitable for local testing, but for any practical use, you will either need
 to use a reverse proxy, or configure Synapse to expose an HTTPS port.
 
 For documentation on using a reverse proxy, see
-https://github.com/matrix-org/synapse/blob/master/docs/reverse_proxy.rst.
+https://github.com/matrix-org/synapse/blob/master/docs/reverse_proxy.md.
 
 For more information on enabling TLS support in synapse itself, see
 https://github.com/matrix-org/synapse/blob/master/INSTALL.md#tls-certificates. Of
diff --git a/docs/CAPTCHA_SETUP.md b/docs/CAPTCHA_SETUP.md
index 5f9057530b..331e5d059a 100644
--- a/docs/CAPTCHA_SETUP.md
+++ b/docs/CAPTCHA_SETUP.md
@@ -4,7 +4,7 @@ The captcha mechanism used is Google's ReCaptcha. This requires API keys from Go
 
 ## Getting keys
 
-Requires a public/private key pair from:
+Requires a site/secret key pair from:
 
 <https://developers.google.com/recaptcha/>
 
@@ -15,8 +15,8 @@ Must be a reCAPTCHA v2 key using the "I'm not a robot" Checkbox option
 The keys are a config option on the home server config. If they are not
 visible, you can generate them via `--generate-config`. Set the following value:
 
-    recaptcha_public_key: YOUR_PUBLIC_KEY
-    recaptcha_private_key: YOUR_PRIVATE_KEY
+    recaptcha_public_key: YOUR_SITE_KEY
+    recaptcha_private_key: YOUR_SECRET_KEY
 
 In addition, you MUST enable captchas via:
 
diff --git a/docs/sample_config.yaml b/docs/sample_config.yaml
index 6c81c0db75..d2f4aff826 100644
--- a/docs/sample_config.yaml
+++ b/docs/sample_config.yaml
@@ -955,7 +955,7 @@ uploads_path: "DATADIR/uploads"
 # If a delegate is specified, the config option public_baseurl must also be filled out.
 #
 account_threepid_delegates:
-    #email: https://example.com     # Delegate email sending to example.org
+    #email: https://example.com     # Delegate email sending to example.com
     #msisdn: http://localhost:8090  # Delegate SMS sending to this local process
 
 # Users who register on this homeserver will automatically be joined
diff --git a/docs/tcp_replication.md b/docs/tcp_replication.md
index e099d8a87b..ba9e874d07 100644
--- a/docs/tcp_replication.md
+++ b/docs/tcp_replication.md
@@ -199,7 +199,20 @@ client (C):
 
 #### REPLICATE (C)
 
-   Asks the server to replicate a given stream
+Asks the server to replicate a given stream. The syntax is:
+
+```
+    REPLICATE <stream_name> <token>
+```
+
+Where `<token>` may be either:
+ * a numeric stream_id to stream updates since (exclusive)
+ * `NOW` to stream all subsequent updates.
+
+The `<stream_name>` is the name of a replication stream to subscribe 
+to (see [here](../synapse/replication/tcp/streams/_base.py) for a list
+of streams). It can also be `ALL` to subscribe to all known streams,
+in which case the `<token>` must be set to `NOW`.
 
 #### USER_SYNC (C)
 
diff --git a/mypy.ini b/mypy.ini
index ffadaddc0b..1d77c0ecc8 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -1,8 +1,11 @@
 [mypy]
-namespace_packages=True
-plugins=mypy_zope:plugin
-follow_imports=skip
-mypy_path=stubs
+namespace_packages = True
+plugins = mypy_zope:plugin
+follow_imports = normal
+check_untyped_defs = True
+show_error_codes = True
+show_traceback = True
+mypy_path = stubs
 
 [mypy-zope]
 ignore_missing_imports = True
diff --git a/scripts-dev/lint.sh b/scripts-dev/lint.sh
index 02a2ca39e5..34c4854e11 100755
--- a/scripts-dev/lint.sh
+++ b/scripts-dev/lint.sh
@@ -7,7 +7,15 @@
 
 set -e
 
-isort -y -rc synapse tests scripts-dev scripts
-flake8 synapse tests
-python3 -m black synapse tests scripts-dev scripts
+if [ $# -ge 1 ]
+then
+  files=$*
+else
+  files="synapse tests scripts-dev scripts"
+fi
+
+echo "Linting these locations: $files"
+isort -y -rc $files
+flake8 $files
+python3 -m black $files
 ./scripts-dev/config-lint.sh
diff --git a/scripts-dev/update_database b/scripts-dev/update_database
new file mode 100755
index 0000000000..27a1ad1e7e
--- /dev/null
+++ b/scripts-dev/update_database
@@ -0,0 +1,124 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+# Copyright 2019 The Matrix.org Foundation C.I.C.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import argparse
+import logging
+import sys
+
+import yaml
+
+from twisted.internet import defer, reactor
+
+from synapse.config.homeserver import HomeServerConfig
+from synapse.metrics.background_process_metrics import run_as_background_process
+from synapse.server import HomeServer
+from synapse.storage import DataStore
+from synapse.storage.engines import create_engine
+from synapse.storage.prepare_database import prepare_database
+
+logger = logging.getLogger("update_database")
+
+
+class MockHomeserver(HomeServer):
+    DATASTORE_CLASS = DataStore
+
+    def __init__(self, config, database_engine, db_conn, **kwargs):
+        super(MockHomeserver, self).__init__(
+            config.server_name,
+            reactor=reactor,
+            config=config,
+            database_engine=database_engine,
+            **kwargs
+        )
+
+        self.database_engine = database_engine
+        self.db_conn = db_conn
+
+    def get_db_conn(self):
+        return self.db_conn
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(
+        description=(
+            "Updates a synapse database to the latest schema and runs background updates"
+            " on it."
+        )
+    )
+    parser.add_argument("-v", action='store_true')
+    parser.add_argument(
+        "--database-config",
+        type=argparse.FileType('r'),
+        required=True,
+        help="A database config file for either a SQLite3 database or a PostgreSQL one.",
+    )
+
+    args = parser.parse_args()
+
+    logging_config = {
+        "level": logging.DEBUG if args.v else logging.INFO,
+        "format": "%(asctime)s - %(name)s - %(lineno)d - %(levelname)s - %(message)s",
+    }
+
+    logging.basicConfig(**logging_config)
+
+    # Load, process and sanity-check the config.
+    hs_config = yaml.safe_load(args.database_config)
+
+    if "database" not in hs_config:
+        sys.stderr.write("The configuration file must have a 'database' section.\n")
+        sys.exit(4)
+
+    config = HomeServerConfig()
+    config.parse_config_dict(hs_config, "", "")
+
+    # Create the database engine and a connection to it.
+    database_engine = create_engine(config.database_config)
+    db_conn = database_engine.module.connect(
+        **{
+            k: v
+            for k, v in config.database_config.get("args", {}).items()
+            if not k.startswith("cp_")
+        }
+    )
+
+    # Update the database to the latest schema.
+    prepare_database(db_conn, database_engine, config=config)
+    db_conn.commit()
+
+    # Instantiate and initialise the homeserver object.
+    hs = MockHomeserver(
+        config,
+        database_engine,
+        db_conn,
+        db_config=config.database_config,
+    )
+    # setup instantiates the store within the homeserver object.
+    hs.setup()
+    store = hs.get_datastore()
+
+    @defer.inlineCallbacks
+    def run_background_updates():
+        yield store.run_background_updates(sleep=False)
+        # Stop the reactor to exit the script once every background update is run.
+        reactor.stop()
+
+    # Apply all background updates on the database.
+    reactor.callWhenRunning(lambda: run_as_background_process(
+        "background_updates", run_background_updates
+    ))
+
+    reactor.run()
diff --git a/scripts/move_remote_media_to_new_store.py b/scripts/move_remote_media_to_new_store.py
index 12747c6024..b5b63933ab 100755
--- a/scripts/move_remote_media_to_new_store.py
+++ b/scripts/move_remote_media_to_new_store.py
@@ -72,7 +72,7 @@ def move_media(origin_server, file_id, src_paths, dest_paths):
     # check that the original exists
     original_file = src_paths.remote_media_filepath(origin_server, file_id)
     if not os.path.exists(original_file):
-        logger.warn(
+        logger.warning(
             "Original for %s/%s (%s) does not exist",
             origin_server,
             file_id,
diff --git a/scripts/synapse_port_db b/scripts/synapse_port_db
index 54faed1e83..0d3321682c 100755
--- a/scripts/synapse_port_db
+++ b/scripts/synapse_port_db
@@ -157,7 +157,7 @@ class Store(
                         )
                     except self.database_engine.module.DatabaseError as e:
                         if self.database_engine.is_deadlock(e):
-                            logger.warn("[TXN DEADLOCK] {%s} %d/%d", desc, i, N)
+                            logger.warning("[TXN DEADLOCK] {%s} %d/%d", desc, i, N)
                             if i < N:
                                 i += 1
                                 conn.rollback()
@@ -432,7 +432,7 @@ class Porter(object):
                     for row in rows:
                         d = dict(zip(headers, row))
                         if "\0" in d['value']:
-                            logger.warn('dropping search row %s', d)
+                            logger.warning('dropping search row %s', d)
                         else:
                             rows_dict.append(d)
 
@@ -647,7 +647,7 @@ class Porter(object):
             if isinstance(col, bytes):
                 return bytearray(col)
             elif isinstance(col, string_types) and "\0" in col:
-                logger.warn(
+                logger.warning(
                     "DROPPING ROW: NUL value in table %s col %s: %r",
                     table,
                     headers[j],
diff --git a/synapse/api/auth.py b/synapse/api/auth.py
index 53f3bb0fa8..5d0b7d2801 100644
--- a/synapse/api/auth.py
+++ b/synapse/api/auth.py
@@ -497,7 +497,7 @@ class Auth(object):
         token = self.get_access_token_from_request(request)
         service = self.store.get_app_service_by_token(token)
         if not service:
-            logger.warn("Unrecognised appservice access token.")
+            logger.warning("Unrecognised appservice access token.")
             raise InvalidClientTokenError()
         request.authenticated_entity = service.sender
         return defer.succeed(service)
diff --git a/synapse/api/constants.py b/synapse/api/constants.py
index 312196675e..49c4b85054 100644
--- a/synapse/api/constants.py
+++ b/synapse/api/constants.py
@@ -138,3 +138,10 @@ class LimitBlockingTypes(object):
 
     MONTHLY_ACTIVE_USER = "monthly_active_user"
     HS_DISABLED = "hs_disabled"
+
+
+class EventContentFields(object):
+    """Fields found in events' content, regardless of type."""
+
+    # Labels for the event, cf https://github.com/matrix-org/matrix-doc/pull/2326
+    LABELS = "org.matrix.labels"
diff --git a/synapse/api/filtering.py b/synapse/api/filtering.py
index 9f06556bd2..bec13f08d8 100644
--- a/synapse/api/filtering.py
+++ b/synapse/api/filtering.py
@@ -20,6 +20,7 @@ from jsonschema import FormatChecker
 
 from twisted.internet import defer
 
+from synapse.api.constants import EventContentFields
 from synapse.api.errors import SynapseError
 from synapse.storage.presence import UserPresenceState
 from synapse.types import RoomID, UserID
@@ -66,6 +67,10 @@ ROOM_EVENT_FILTER_SCHEMA = {
         "contains_url": {"type": "boolean"},
         "lazy_load_members": {"type": "boolean"},
         "include_redundant_members": {"type": "boolean"},
+        # Include or exclude events with the provided labels.
+        # cf https://github.com/matrix-org/matrix-doc/pull/2326
+        "org.matrix.labels": {"type": "array", "items": {"type": "string"}},
+        "org.matrix.not_labels": {"type": "array", "items": {"type": "string"}},
     },
 }
 
@@ -259,6 +264,9 @@ class Filter(object):
 
         self.contains_url = self.filter_json.get("contains_url", None)
 
+        self.labels = self.filter_json.get("org.matrix.labels", None)
+        self.not_labels = self.filter_json.get("org.matrix.not_labels", [])
+
     def filters_all_types(self):
         return "*" in self.not_types
 
@@ -282,6 +290,7 @@ class Filter(object):
             room_id = None
             ev_type = "m.presence"
             contains_url = False
+            labels = []
         else:
             sender = event.get("sender", None)
             if not sender:
@@ -300,10 +309,11 @@ class Filter(object):
             content = event.get("content", {})
             # check if there is a string url field in the content for filtering purposes
             contains_url = isinstance(content.get("url"), text_type)
+            labels = content.get(EventContentFields.LABELS, [])
 
-        return self.check_fields(room_id, sender, ev_type, contains_url)
+        return self.check_fields(room_id, sender, ev_type, labels, contains_url)
 
-    def check_fields(self, room_id, sender, event_type, contains_url):
+    def check_fields(self, room_id, sender, event_type, labels, contains_url):
         """Checks whether the filter matches the given event fields.
 
         Returns:
@@ -313,6 +323,7 @@ class Filter(object):
             "rooms": lambda v: room_id == v,
             "senders": lambda v: sender == v,
             "types": lambda v: _matches_wildcard(event_type, v),
+            "labels": lambda v: v in labels,
         }
 
         for name, match_func in literal_keys.items():
diff --git a/synapse/app/__init__.py b/synapse/app/__init__.py
index d877c77834..a01bac2997 100644
--- a/synapse/app/__init__.py
+++ b/synapse/app/__init__.py
@@ -44,6 +44,8 @@ def check_bind_error(e, address, bind_addresses):
         bind_addresses (list): Addresses on which the service listens.
     """
     if address == "0.0.0.0" and "::" in bind_addresses:
-        logger.warn("Failed to listen on 0.0.0.0, continuing because listening on [::]")
+        logger.warning(
+            "Failed to listen on 0.0.0.0, continuing because listening on [::]"
+        )
     else:
         raise e
diff --git a/synapse/app/appservice.py b/synapse/app/appservice.py
index 767b87d2db..02b900f382 100644
--- a/synapse/app/appservice.py
+++ b/synapse/app/appservice.py
@@ -94,7 +94,7 @@ class AppserviceServer(HomeServer):
                 )
             elif listener["type"] == "metrics":
                 if not self.get_config().enable_metrics:
-                    logger.warn(
+                    logger.warning(
                         (
                             "Metrics listener configured, but "
                             "enable_metrics is not True!"
@@ -103,7 +103,7 @@ class AppserviceServer(HomeServer):
                 else:
                     _base.listen_metrics(listener["bind_addresses"], listener["port"])
             else:
-                logger.warn("Unrecognized listener type: %s", listener["type"])
+                logger.warning("Unrecognized listener type: %s", listener["type"])
 
         self.get_tcp_replication().start_replication(self)
 
diff --git a/synapse/app/client_reader.py b/synapse/app/client_reader.py
index dbcc414c42..dadb487d5f 100644
--- a/synapse/app/client_reader.py
+++ b/synapse/app/client_reader.py
@@ -153,7 +153,7 @@ class ClientReaderServer(HomeServer):
                 )
             elif listener["type"] == "metrics":
                 if not self.get_config().enable_metrics:
-                    logger.warn(
+                    logger.warning(
                         (
                             "Metrics listener configured, but "
                             "enable_metrics is not True!"
@@ -162,7 +162,7 @@ class ClientReaderServer(HomeServer):
                 else:
                     _base.listen_metrics(listener["bind_addresses"], listener["port"])
             else:
-                logger.warn("Unrecognized listener type: %s", listener["type"])
+                logger.warning("Unrecognized listener type: %s", listener["type"])
 
         self.get_tcp_replication().start_replication(self)
 
diff --git a/synapse/app/event_creator.py b/synapse/app/event_creator.py
index f20d810ece..d110599a35 100644
--- a/synapse/app/event_creator.py
+++ b/synapse/app/event_creator.py
@@ -147,7 +147,7 @@ class EventCreatorServer(HomeServer):
                 )
             elif listener["type"] == "metrics":
                 if not self.get_config().enable_metrics:
-                    logger.warn(
+                    logger.warning(
                         (
                             "Metrics listener configured, but "
                             "enable_metrics is not True!"
@@ -156,7 +156,7 @@ class EventCreatorServer(HomeServer):
                 else:
                     _base.listen_metrics(listener["bind_addresses"], listener["port"])
             else:
-                logger.warn("Unrecognized listener type: %s", listener["type"])
+                logger.warning("Unrecognized listener type: %s", listener["type"])
 
         self.get_tcp_replication().start_replication(self)
 
diff --git a/synapse/app/federation_reader.py b/synapse/app/federation_reader.py
index 1ef027a88c..418c086254 100644
--- a/synapse/app/federation_reader.py
+++ b/synapse/app/federation_reader.py
@@ -132,7 +132,7 @@ class FederationReaderServer(HomeServer):
                 )
             elif listener["type"] == "metrics":
                 if not self.get_config().enable_metrics:
-                    logger.warn(
+                    logger.warning(
                         (
                             "Metrics listener configured, but "
                             "enable_metrics is not True!"
@@ -141,7 +141,7 @@ class FederationReaderServer(HomeServer):
                 else:
                     _base.listen_metrics(listener["bind_addresses"], listener["port"])
             else:
-                logger.warn("Unrecognized listener type: %s", listener["type"])
+                logger.warning("Unrecognized listener type: %s", listener["type"])
 
         self.get_tcp_replication().start_replication(self)
 
diff --git a/synapse/app/federation_sender.py b/synapse/app/federation_sender.py
index 04fbb407af..139221ad34 100644
--- a/synapse/app/federation_sender.py
+++ b/synapse/app/federation_sender.py
@@ -123,7 +123,7 @@ class FederationSenderServer(HomeServer):
                 )
             elif listener["type"] == "metrics":
                 if not self.get_config().enable_metrics:
-                    logger.warn(
+                    logger.warning(
                         (
                             "Metrics listener configured, but "
                             "enable_metrics is not True!"
@@ -132,7 +132,7 @@ class FederationSenderServer(HomeServer):
                 else:
                     _base.listen_metrics(listener["bind_addresses"], listener["port"])
             else:
-                logger.warn("Unrecognized listener type: %s", listener["type"])
+                logger.warning("Unrecognized listener type: %s", listener["type"])
 
         self.get_tcp_replication().start_replication(self)
 
diff --git a/synapse/app/frontend_proxy.py b/synapse/app/frontend_proxy.py
index 9504bfbc70..e647459d0e 100644
--- a/synapse/app/frontend_proxy.py
+++ b/synapse/app/frontend_proxy.py
@@ -204,7 +204,7 @@ class FrontendProxyServer(HomeServer):
                 )
             elif listener["type"] == "metrics":
                 if not self.get_config().enable_metrics:
-                    logger.warn(
+                    logger.warning(
                         (
                             "Metrics listener configured, but "
                             "enable_metrics is not True!"
@@ -213,7 +213,7 @@ class FrontendProxyServer(HomeServer):
                 else:
                     _base.listen_metrics(listener["bind_addresses"], listener["port"])
             else:
-                logger.warn("Unrecognized listener type: %s", listener["type"])
+                logger.warning("Unrecognized listener type: %s", listener["type"])
 
         self.get_tcp_replication().start_replication(self)
 
diff --git a/synapse/app/homeserver.py b/synapse/app/homeserver.py
index eb54f56853..73e2c29d06 100644
--- a/synapse/app/homeserver.py
+++ b/synapse/app/homeserver.py
@@ -19,12 +19,13 @@ from __future__ import print_function
 
 import gc
 import logging
+import math
 import os
+import resource
 import sys
 
 from six import iteritems
 
-import psutil
 from prometheus_client import Gauge
 
 from twisted.application import service
@@ -282,7 +283,7 @@ class SynapseHomeServer(HomeServer):
                     reactor.addSystemEventTrigger("before", "shutdown", s.stopListening)
             elif listener["type"] == "metrics":
                 if not self.get_config().enable_metrics:
-                    logger.warn(
+                    logger.warning(
                         (
                             "Metrics listener configured, but "
                             "enable_metrics is not True!"
@@ -291,7 +292,7 @@ class SynapseHomeServer(HomeServer):
                 else:
                     _base.listen_metrics(listener["bind_addresses"], listener["port"])
             else:
-                logger.warn("Unrecognized listener type: %s", listener["type"])
+                logger.warning("Unrecognized listener type: %s", listener["type"])
 
     def run_startup_checks(self, db_conn, database_engine):
         all_users_native = are_all_users_on_domain(
@@ -471,6 +472,87 @@ class SynapseService(service.Service):
         return self._port.stopListening()
 
 
+# Contains the list of processes we will be monitoring
+# currently either 0 or 1
+_stats_process = []
+
+
+@defer.inlineCallbacks
+def phone_stats_home(hs, stats, stats_process=_stats_process):
+    logger.info("Gathering stats for reporting")
+    now = int(hs.get_clock().time())
+    uptime = int(now - hs.start_time)
+    if uptime < 0:
+        uptime = 0
+
+    stats["homeserver"] = hs.config.server_name
+    stats["server_context"] = hs.config.server_context
+    stats["timestamp"] = now
+    stats["uptime_seconds"] = uptime
+    version = sys.version_info
+    stats["python_version"] = "{}.{}.{}".format(
+        version.major, version.minor, version.micro
+    )
+    stats["total_users"] = yield hs.get_datastore().count_all_users()
+
+    total_nonbridged_users = yield hs.get_datastore().count_nonbridged_users()
+    stats["total_nonbridged_users"] = total_nonbridged_users
+
+    daily_user_type_results = yield hs.get_datastore().count_daily_user_type()
+    for name, count in iteritems(daily_user_type_results):
+        stats["daily_user_type_" + name] = count
+
+    room_count = yield hs.get_datastore().get_room_count()
+    stats["total_room_count"] = room_count
+
+    stats["daily_active_users"] = yield hs.get_datastore().count_daily_users()
+    stats["monthly_active_users"] = yield hs.get_datastore().count_monthly_users()
+    stats["daily_active_rooms"] = yield hs.get_datastore().count_daily_active_rooms()
+    stats["daily_messages"] = yield hs.get_datastore().count_daily_messages()
+
+    r30_results = yield hs.get_datastore().count_r30_users()
+    for name, count in iteritems(r30_results):
+        stats["r30_users_" + name] = count
+
+    daily_sent_messages = yield hs.get_datastore().count_daily_sent_messages()
+    stats["daily_sent_messages"] = daily_sent_messages
+    stats["cache_factor"] = CACHE_SIZE_FACTOR
+    stats["event_cache_size"] = hs.config.event_cache_size
+
+    #
+    # Performance statistics
+    #
+    old = stats_process[0]
+    new = (now, resource.getrusage(resource.RUSAGE_SELF))
+    stats_process[0] = new
+
+    # Get RSS in bytes
+    stats["memory_rss"] = new[1].ru_maxrss
+
+    # Get CPU time in % of a single core, not % of all cores
+    used_cpu_time = (new[1].ru_utime + new[1].ru_stime) - (
+        old[1].ru_utime + old[1].ru_stime
+    )
+    if used_cpu_time == 0 or new[0] == old[0]:
+        stats["cpu_average"] = 0
+    else:
+        stats["cpu_average"] = math.floor(used_cpu_time / (new[0] - old[0]) * 100)
+
+    #
+    # Database version
+    #
+
+    stats["database_engine"] = hs.get_datastore().database_engine_name
+    stats["database_server_version"] = hs.get_datastore().get_server_version()
+    logger.info("Reporting stats to %s: %s" % (hs.config.report_stats_endpoint, stats))
+    try:
+        yield hs.get_proxied_http_client().put_json(
+            hs.config.report_stats_endpoint, stats
+        )
+    except Exception as e:
+        logger.warning("Error reporting stats: %s", e)
+
+
 def run(hs):
     PROFILE_SYNAPSE = False
     if PROFILE_SYNAPSE:
@@ -497,91 +579,19 @@ def run(hs):
         reactor.run = profile(reactor.run)
 
     clock = hs.get_clock()
-    start_time = clock.time()
 
     stats = {}
 
-    # Contains the list of processes we will be monitoring
-    # currently either 0 or 1
-    stats_process = []
+    def performance_stats_init():
+        _stats_process.clear()
+        _stats_process.append(
+            (int(hs.get_clock().time(), resource.getrusage(resource.RUSAGE_SELF)))
+        )
 
     def start_phone_stats_home():
-        return run_as_background_process("phone_stats_home", phone_stats_home)
-
-    @defer.inlineCallbacks
-    def phone_stats_home():
-        logger.info("Gathering stats for reporting")
-        now = int(hs.get_clock().time())
-        uptime = int(now - start_time)
-        if uptime < 0:
-            uptime = 0
-
-        stats["homeserver"] = hs.config.server_name
-        stats["server_context"] = hs.config.server_context
-        stats["timestamp"] = now
-        stats["uptime_seconds"] = uptime
-        version = sys.version_info
-        stats["python_version"] = "{}.{}.{}".format(
-            version.major, version.minor, version.micro
-        )
-        stats["total_users"] = yield hs.get_datastore().count_all_users()
-
-        total_nonbridged_users = yield hs.get_datastore().count_nonbridged_users()
-        stats["total_nonbridged_users"] = total_nonbridged_users
-
-        daily_user_type_results = yield hs.get_datastore().count_daily_user_type()
-        for name, count in iteritems(daily_user_type_results):
-            stats["daily_user_type_" + name] = count
-
-        room_count = yield hs.get_datastore().get_room_count()
-        stats["total_room_count"] = room_count
-
-        stats["daily_active_users"] = yield hs.get_datastore().count_daily_users()
-        stats["monthly_active_users"] = yield hs.get_datastore().count_monthly_users()
-        stats[
-            "daily_active_rooms"
-        ] = yield hs.get_datastore().count_daily_active_rooms()
-        stats["daily_messages"] = yield hs.get_datastore().count_daily_messages()
-
-        r30_results = yield hs.get_datastore().count_r30_users()
-        for name, count in iteritems(r30_results):
-            stats["r30_users_" + name] = count
-
-        daily_sent_messages = yield hs.get_datastore().count_daily_sent_messages()
-        stats["daily_sent_messages"] = daily_sent_messages
-        stats["cache_factor"] = CACHE_SIZE_FACTOR
-        stats["event_cache_size"] = hs.config.event_cache_size
-
-        if len(stats_process) > 0:
-            stats["memory_rss"] = 0
-            stats["cpu_average"] = 0
-            for process in stats_process:
-                stats["memory_rss"] += process.memory_info().rss
-                stats["cpu_average"] += int(process.cpu_percent(interval=None))
-
-        stats["database_engine"] = hs.get_datastore().database_engine_name
-        stats["database_server_version"] = hs.get_datastore().get_server_version()
-        logger.info(
-            "Reporting stats to %s: %s" % (hs.config.report_stats_endpoint, stats)
+        return run_as_background_process(
+            "phone_stats_home", phone_stats_home, hs, stats
         )
-        try:
-            yield hs.get_simple_http_client().put_json(
-                hs.config.report_stats_endpoint, stats
-            )
-        except Exception as e:
-            logger.warn("Error reporting stats: %s", e)
-
-    def performance_stats_init():
-        try:
-            process = psutil.Process()
-            # Ensure we can fetch both, and make the initial request for cpu_percent
-            # so the next request will use this as the initial point.
-            process.memory_info().rss
-            process.cpu_percent(interval=None)
-            logger.info("report_stats can use psutil")
-            stats_process.append(process)
-        except (AttributeError):
-            logger.warning("Unable to read memory/cpu stats. Disabling reporting.")
 
     def generate_user_daily_visit_stats():
         return run_as_background_process(
diff --git a/synapse/app/media_repository.py b/synapse/app/media_repository.py
index 6bc7202f33..2c6dd3ef02 100644
--- a/synapse/app/media_repository.py
+++ b/synapse/app/media_repository.py
@@ -120,7 +120,7 @@ class MediaRepositoryServer(HomeServer):
                 )
             elif listener["type"] == "metrics":
                 if not self.get_config().enable_metrics:
-                    logger.warn(
+                    logger.warning(
                         (
                             "Metrics listener configured, but "
                             "enable_metrics is not True!"
@@ -129,7 +129,7 @@ class MediaRepositoryServer(HomeServer):
                 else:
                     _base.listen_metrics(listener["bind_addresses"], listener["port"])
             else:
-                logger.warn("Unrecognized listener type: %s", listener["type"])
+                logger.warning("Unrecognized listener type: %s", listener["type"])
 
         self.get_tcp_replication().start_replication(self)
 
diff --git a/synapse/app/pusher.py b/synapse/app/pusher.py
index d84732ee3c..01a5ffc363 100644
--- a/synapse/app/pusher.py
+++ b/synapse/app/pusher.py
@@ -114,7 +114,7 @@ class PusherServer(HomeServer):
                 )
             elif listener["type"] == "metrics":
                 if not self.get_config().enable_metrics:
-                    logger.warn(
+                    logger.warning(
                         (
                             "Metrics listener configured, but "
                             "enable_metrics is not True!"
@@ -123,7 +123,7 @@ class PusherServer(HomeServer):
                 else:
                     _base.listen_metrics(listener["bind_addresses"], listener["port"])
             else:
-                logger.warn("Unrecognized listener type: %s", listener["type"])
+                logger.warning("Unrecognized listener type: %s", listener["type"])
 
         self.get_tcp_replication().start_replication(self)
 
diff --git a/synapse/app/synchrotron.py b/synapse/app/synchrotron.py
index 6a7e2fa707..b14da09f47 100644
--- a/synapse/app/synchrotron.py
+++ b/synapse/app/synchrotron.py
@@ -326,7 +326,7 @@ class SynchrotronServer(HomeServer):
                 )
             elif listener["type"] == "metrics":
                 if not self.get_config().enable_metrics:
-                    logger.warn(
+                    logger.warning(
                         (
                             "Metrics listener configured, but "
                             "enable_metrics is not True!"
@@ -335,7 +335,7 @@ class SynchrotronServer(HomeServer):
                 else:
                     _base.listen_metrics(listener["bind_addresses"], listener["port"])
             else:
-                logger.warn("Unrecognized listener type: %s", listener["type"])
+                logger.warning("Unrecognized listener type: %s", listener["type"])
 
         self.get_tcp_replication().start_replication(self)
 
diff --git a/synapse/app/user_dir.py b/synapse/app/user_dir.py
index a5d6dc7915..6cb100319f 100644
--- a/synapse/app/user_dir.py
+++ b/synapse/app/user_dir.py
@@ -150,7 +150,7 @@ class UserDirectoryServer(HomeServer):
                 )
             elif listener["type"] == "metrics":
                 if not self.get_config().enable_metrics:
-                    logger.warn(
+                    logger.warning(
                         (
                             "Metrics listener configured, but "
                             "enable_metrics is not True!"
@@ -159,7 +159,7 @@ class UserDirectoryServer(HomeServer):
                 else:
                     _base.listen_metrics(listener["bind_addresses"], listener["port"])
             else:
-                logger.warn("Unrecognized listener type: %s", listener["type"])
+                logger.warning("Unrecognized listener type: %s", listener["type"])
 
         self.get_tcp_replication().start_replication(self)
 
diff --git a/synapse/appservice/__init__.py b/synapse/appservice/__init__.py
index 33b3579425..aea3985a5f 100644
--- a/synapse/appservice/__init__.py
+++ b/synapse/appservice/__init__.py
@@ -94,7 +94,9 @@ class ApplicationService(object):
         ip_range_whitelist=None,
     ):
         self.token = token
-        self.url = url
+        self.url = (
+            url.rstrip("/") if isinstance(url, str) else None
+        )  # url must not end with a slash
         self.hs_token = hs_token
         self.sender = sender
         self.server_name = hostname
diff --git a/synapse/config/key.py b/synapse/config/key.py
index ec5d430afb..52ff1b2621 100644
--- a/synapse/config/key.py
+++ b/synapse/config/key.py
@@ -125,7 +125,7 @@ class KeyConfig(Config):
 
         # if neither trusted_key_servers nor perspectives are given, use the default.
         if "perspectives" not in config and "trusted_key_servers" not in config:
-            logger.warn(TRUSTED_KEY_SERVER_NOT_CONFIGURED_WARN)
+            logger.warning(TRUSTED_KEY_SERVER_NOT_CONFIGURED_WARN)
             key_servers = [{"server_name": "matrix.org"}]
         else:
             key_servers = config.get("trusted_key_servers", [])
@@ -156,7 +156,7 @@ class KeyConfig(Config):
         if not self.macaroon_secret_key:
             # Unfortunately, there are people out there that don't have this
             # set. Lets just be "nice" and derive one from their secret key.
-            logger.warn("Config is missing macaroon_secret_key")
+            logger.warning("Config is missing macaroon_secret_key")
             seed = bytes(self.signing_key[0])
             self.macaroon_secret_key = hashlib.sha256(seed).digest()
 
diff --git a/synapse/config/logger.py b/synapse/config/logger.py
index be92e33f93..75bb904718 100644
--- a/synapse/config/logger.py
+++ b/synapse/config/logger.py
@@ -182,7 +182,7 @@ def _reload_stdlib_logging(*args, log_config=None):
     logger = logging.getLogger("")
 
     if not log_config:
-        logger.warn("Reloaded a blank config?")
+        logger.warning("Reloaded a blank config?")
 
     logging.config.dictConfig(log_config)
 
@@ -234,8 +234,8 @@ def setup_logging(
 
     # make sure that the first thing we log is a thing we can grep backwards
     # for
-    logging.warn("***** STARTING SERVER *****")
-    logging.warn("Server %s version %s", sys.argv[0], get_version_string(synapse))
+    logging.warning("***** STARTING SERVER *****")
+    logging.warning("Server %s version %s", sys.argv[0], get_version_string(synapse))
     logging.info("Server hostname: %s", config.server_name)
 
     return logger
diff --git a/synapse/config/registration.py b/synapse/config/registration.py
index ab41623b2b..1f6dac69da 100644
--- a/synapse/config/registration.py
+++ b/synapse/config/registration.py
@@ -300,7 +300,7 @@ class RegistrationConfig(Config):
         # If a delegate is specified, the config option public_baseurl must also be filled out.
         #
         account_threepid_delegates:
-            #email: https://example.com     # Delegate email sending to example.org
+            #email: https://example.com     # Delegate email sending to example.com
             #msisdn: http://localhost:8090  # Delegate SMS sending to this local process
 
         # Users who register on this homeserver will automatically be joined
diff --git a/synapse/crypto/event_signing.py b/synapse/crypto/event_signing.py
index 694fb2c816..ccaa8a9920 100644
--- a/synapse/crypto/event_signing.py
+++ b/synapse/crypto/event_signing.py
@@ -125,9 +125,11 @@ def compute_event_signature(event_dict, signature_name, signing_key):
     redact_json = prune_event_dict(event_dict)
     redact_json.pop("age_ts", None)
     redact_json.pop("unsigned", None)
-    logger.debug("Signing event: %s", encode_canonical_json(redact_json))
+    if logger.isEnabledFor(logging.DEBUG):
+        logger.debug("Signing event: %s", encode_canonical_json(redact_json))
     redact_json = sign_json(redact_json, signature_name, signing_key)
-    logger.debug("Signed event: %s", encode_canonical_json(redact_json))
+    if logger.isEnabledFor(logging.DEBUG):
+        logger.debug("Signed event: %s", encode_canonical_json(redact_json))
     return redact_json["signatures"]
 
 
diff --git a/synapse/event_auth.py b/synapse/event_auth.py
index e7b722547b..ec3243b27b 100644
--- a/synapse/event_auth.py
+++ b/synapse/event_auth.py
@@ -77,7 +77,7 @@ def check(room_version, event, auth_events, do_sig_check=True, do_size_check=Tru
     if auth_events is None:
         # Oh, we don't know what the state of the room was, so we
         # are trusting that this is allowed (at least for now)
-        logger.warn("Trusting event: %s", event.event_id)
+        logger.warning("Trusting event: %s", event.event_id)
         return
 
     if event.type == EventTypes.Create:
diff --git a/synapse/events/snapshot.py b/synapse/events/snapshot.py
index acbcbeeced..64e898f40c 100644
--- a/synapse/events/snapshot.py
+++ b/synapse/events/snapshot.py
@@ -12,104 +12,125 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+from typing import Dict, Optional, Tuple, Union
 
 from six import iteritems
 
+import attr
 from frozendict import frozendict
 
 from twisted.internet import defer
 
+from synapse.appservice import ApplicationService
 from synapse.logging.context import make_deferred_yieldable, run_in_background
 
 
-class EventContext(object):
+@attr.s(slots=True)
+class EventContext:
     """
+    Holds information relevant to persisting an event
+
     Attributes:
-        state_group (int|None): state group id, if the state has been stored
-            as a state group. This is usually only None if e.g. the event is
-            an outlier.
-        rejected (bool|str): A rejection reason if the event was rejected, else
-            False
-
-        push_actions (list[(str, list[object])]): list of (user_id, actions)
-            tuples
-
-        prev_group (int): Previously persisted state group. ``None`` for an
-            outlier.
-        delta_ids (dict[(str, str), str]): Delta from ``prev_group``.
-            (type, state_key) -> event_id. ``None`` for an outlier.
-
-        prev_state_events (?): XXX: is this ever set to anything other than
-            the empty list?
-
-        _current_state_ids (dict[(str, str), str]|None):
-            The current state map including the current event. None if outlier
-            or we haven't fetched the state from DB yet.
-            (type, state_key) -> event_id
+        rejected: A rejection reason if the event was rejected, else False
+
+        _state_group: The ID of the state group for this event. Note that state events
+            are persisted with a state group which includes the new event, so this is
+            effectively the state *after* the event in question.
+
+            For a *rejected* state event, where the state of the rejected event is
+            ignored, this state_group should never make it into the
+            event_to_state_groups table. Indeed, inspecting this value for a rejected
+            state event is almost certainly incorrect.
+
+            For an outlier, where we don't have the state at the event, this will be
+            None.
+
+            Note that this is a private attribute: it should be accessed via
+            the ``state_group`` property.
+
+        state_group_before_event: The ID of the state group representing the state
+            of the room before this event.
+
+            If this is a non-state event, this will be the same as ``state_group``. If
+            it's a state event, it will be the same as ``prev_group``.
+
+            If ``state_group`` is None (ie, the event is an outlier),
+            ``state_group_before_event`` will always also be ``None``.
+
+        prev_group: If it is known, ``state_group``'s prev_group. Note that this being
+            None does not necessarily mean that ``state_group`` does not have
+            a prev_group!
+
+            If the event is a state event, this is normally the same as ``prev_group``.
+
+            If ``state_group`` is None (ie, the event is an outlier), ``prev_group``
+            will always also be ``None``.
+
+            Note that this *not* (necessarily) the state group associated with
+            ``_prev_state_ids``.
+
+        delta_ids: If ``prev_group`` is not None, the state delta between ``prev_group``
+            and ``state_group``.
+
+        app_service: If this event is being sent by a (local) application service, that
+            app service.
+
+        _current_state_ids: The room state map, including this event - ie, the state
+            in ``state_group``.
 
-        _prev_state_ids (dict[(str, str), str]|None):
-            The current state map excluding the current event. None if outlier
-            or we haven't fetched the state from DB yet.
             (type, state_key) -> event_id
 
-        _fetching_state_deferred (Deferred|None): Resolves when *_state_ids have
-            been calculated. None if we haven't started calculating yet
+            FIXME: what is this for an outlier? it seems ill-defined. It seems like
+            it could be either {}, or the state we were given by the remote
+            server, depending on $THINGS
 
-        _event_type (str): The type of the event the context is associated with.
-            Only set when state has not been fetched yet.
+            Note that this is a private attribute: it should be accessed via
+            ``get_current_state_ids``. _AsyncEventContext impl calculates this
+            on-demand: it will be None until that happens.
 
-        _event_state_key (str|None): The state_key of the event the context is
-            associated with. Only set when state has not been fetched yet.
+        _prev_state_ids: The room state map, excluding this event - ie, the state
+            in ``state_group_before_event``. For a non-state
+            event, this will be the same as _current_state_events.
 
-        _prev_state_id (str|None): If the event associated with the context is
-            a state event, then `_prev_state_id` is the event_id of the state
-            that was replaced.
-            Only set when state has not been fetched yet.
-    """
+            Note that it is a completely different thing to prev_group!
 
-    __slots__ = [
-        "state_group",
-        "rejected",
-        "prev_group",
-        "delta_ids",
-        "prev_state_events",
-        "app_service",
-        "_current_state_ids",
-        "_prev_state_ids",
-        "_prev_state_id",
-        "_event_type",
-        "_event_state_key",
-        "_fetching_state_deferred",
-    ]
-
-    def __init__(self):
-        self.prev_state_events = []
-        self.rejected = False
-        self.app_service = None
+            (type, state_key) -> event_id
 
-    @staticmethod
-    def with_state(
-        state_group, current_state_ids, prev_state_ids, prev_group=None, delta_ids=None
-    ):
-        context = EventContext()
+            FIXME: again, what is this for an outlier?
 
-        # The current state including the current event
-        context._current_state_ids = current_state_ids
-        # The current state excluding the current event
-        context._prev_state_ids = prev_state_ids
-        context.state_group = state_group
+            As with _current_state_ids, this is a private attribute. It should be
+            accessed via get_prev_state_ids.
+    """
 
-        context._prev_state_id = None
-        context._event_type = None
-        context._event_state_key = None
-        context._fetching_state_deferred = defer.succeed(None)
+    rejected = attr.ib(default=False, type=Union[bool, str])
+    _state_group = attr.ib(default=None, type=Optional[int])
+    state_group_before_event = attr.ib(default=None, type=Optional[int])
+    prev_group = attr.ib(default=None, type=Optional[int])
+    delta_ids = attr.ib(default=None, type=Optional[Dict[Tuple[str, str], str]])
+    app_service = attr.ib(default=None, type=Optional[ApplicationService])
 
-        # A previously persisted state group and a delta between that
-        # and this state.
-        context.prev_group = prev_group
-        context.delta_ids = delta_ids
+    _current_state_ids = attr.ib(
+        default=None, type=Optional[Dict[Tuple[str, str], str]]
+    )
+    _prev_state_ids = attr.ib(default=None, type=Optional[Dict[Tuple[str, str], str]])
 
-        return context
+    @staticmethod
+    def with_state(
+        state_group,
+        state_group_before_event,
+        current_state_ids,
+        prev_state_ids,
+        prev_group=None,
+        delta_ids=None,
+    ):
+        return EventContext(
+            current_state_ids=current_state_ids,
+            prev_state_ids=prev_state_ids,
+            state_group=state_group,
+            state_group_before_event=state_group_before_event,
+            prev_group=prev_group,
+            delta_ids=delta_ids,
+        )
 
     @defer.inlineCallbacks
     def serialize(self, event, store):
@@ -137,11 +158,11 @@ class EventContext(object):
             "prev_state_id": prev_state_id,
             "event_type": event.type,
             "event_state_key": event.state_key if event.is_state() else None,
-            "state_group": self.state_group,
+            "state_group": self._state_group,
+            "state_group_before_event": self.state_group_before_event,
             "rejected": self.rejected,
             "prev_group": self.prev_group,
             "delta_ids": _encode_state_dict(self.delta_ids),
-            "prev_state_events": self.prev_state_events,
             "app_service_id": self.app_service.id if self.app_service else None,
         }
 
@@ -157,24 +178,18 @@ class EventContext(object):
         Returns:
             EventContext
         """
-        context = EventContext()
-
-        # We use the state_group and prev_state_id stuff to pull the
-        # current_state_ids out of the DB and construct prev_state_ids.
-        context._prev_state_id = input["prev_state_id"]
-        context._event_type = input["event_type"]
-        context._event_state_key = input["event_state_key"]
-
-        context._current_state_ids = None
-        context._prev_state_ids = None
-        context._fetching_state_deferred = None
-
-        context.state_group = input["state_group"]
-        context.prev_group = input["prev_group"]
-        context.delta_ids = _decode_state_dict(input["delta_ids"])
-
-        context.rejected = input["rejected"]
-        context.prev_state_events = input["prev_state_events"]
+        context = _AsyncEventContextImpl(
+            # We use the state_group and prev_state_id stuff to pull the
+            # current_state_ids out of the DB and construct prev_state_ids.
+            prev_state_id=input["prev_state_id"],
+            event_type=input["event_type"],
+            event_state_key=input["event_state_key"],
+            state_group=input["state_group"],
+            state_group_before_event=input["state_group_before_event"],
+            prev_group=input["prev_group"],
+            delta_ids=_decode_state_dict(input["delta_ids"]),
+            rejected=input["rejected"],
+        )
 
         app_service_id = input["app_service_id"]
         if app_service_id:
@@ -182,29 +197,52 @@ class EventContext(object):
 
         return context
 
+    @property
+    def state_group(self) -> Optional[int]:
+        """The ID of the state group for this event.
+
+        Note that state events are persisted with a state group which includes the new
+        event, so this is effectively the state *after* the event in question.
+
+        For an outlier, where we don't have the state at the event, this will be None.
+
+        It is an error to access this for a rejected event, since rejected state should
+        not make it into the room state. Accessing this property will raise an exception
+        if ``rejected`` is set.
+        """
+        if self.rejected:
+            raise RuntimeError("Attempt to access state_group of rejected event")
+
+        return self._state_group
+
     @defer.inlineCallbacks
     def get_current_state_ids(self, store):
-        """Gets the current state IDs
+        """
+        Gets the room state map, including this event - ie, the state in ``state_group``
+
+        It is an error to access this for a rejected event, since rejected state should
+        not make it into the room state. This method will raise an exception if
+        ``rejected`` is set.
 
         Returns:
             Deferred[dict[(str, str), str]|None]: Returns None if state_group
                 is None, which happens when the associated event is an outlier.
+
                 Maps a (type, state_key) to the event ID of the state event matching
                 this tuple.
         """
+        if self.rejected:
+            raise RuntimeError("Attempt to access state_ids of rejected event")
 
-        if not self._fetching_state_deferred:
-            self._fetching_state_deferred = run_in_background(
-                self._fill_out_state, store
-            )
-
-        yield make_deferred_yieldable(self._fetching_state_deferred)
-
+        yield self._ensure_fetched(store)
         return self._current_state_ids
 
     @defer.inlineCallbacks
     def get_prev_state_ids(self, store):
-        """Gets the prev state IDs
+        """
+        Gets the room state map, excluding this event.
+
+        For a non-state event, this will be the same as get_current_state_ids().
 
         Returns:
             Deferred[dict[(str, str), str]|None]: Returns None if state_group
@@ -212,27 +250,64 @@ class EventContext(object):
                 Maps a (type, state_key) to the event ID of the state event matching
                 this tuple.
         """
-
-        if not self._fetching_state_deferred:
-            self._fetching_state_deferred = run_in_background(
-                self._fill_out_state, store
-            )
-
-        yield make_deferred_yieldable(self._fetching_state_deferred)
-
+        yield self._ensure_fetched(store)
         return self._prev_state_ids
 
     def get_cached_current_state_ids(self):
         """Gets the current state IDs if we have them already cached.
 
+        It is an error to access this for a rejected event, since rejected state should
+        not make it into the room state. This method will raise an exception if
+        ``rejected`` is set.
+
         Returns:
             dict[(str, str), str]|None: Returns None if we haven't cached the
             state or if state_group is None, which happens when the associated
             event is an outlier.
         """
+        if self.rejected:
+            raise RuntimeError("Attempt to access state_ids of rejected event")
 
         return self._current_state_ids
 
+    def _ensure_fetched(self, store):
+        return defer.succeed(None)
+
+
+@attr.s(slots=True)
+class _AsyncEventContextImpl(EventContext):
+    """
+    An implementation of EventContext which fetches _current_state_ids and
+    _prev_state_ids from the database on demand.
+
+    Attributes:
+
+        _fetching_state_deferred (Deferred|None): Resolves when *_state_ids have
+            been calculated. None if we haven't started calculating yet
+
+        _event_type (str): The type of the event the context is associated with.
+
+        _event_state_key (str): The state_key of the event the context is
+            associated with.
+
+        _prev_state_id (str|None): If the event associated with the context is
+            a state event, then `_prev_state_id` is the event_id of the state
+            that was replaced.
+    """
+
+    _prev_state_id = attr.ib(default=None)
+    _event_type = attr.ib(default=None)
+    _event_state_key = attr.ib(default=None)
+    _fetching_state_deferred = attr.ib(default=None)
+
+    def _ensure_fetched(self, store):
+        if not self._fetching_state_deferred:
+            self._fetching_state_deferred = run_in_background(
+                self._fill_out_state, store
+            )
+
+        return make_deferred_yieldable(self._fetching_state_deferred)
+
     @defer.inlineCallbacks
     def _fill_out_state(self, store):
         """Called to populate the _current_state_ids and _prev_state_ids
@@ -250,27 +325,6 @@ class EventContext(object):
         else:
             self._prev_state_ids = self._current_state_ids
 
-    @defer.inlineCallbacks
-    def update_state(
-        self, state_group, prev_state_ids, current_state_ids, prev_group, delta_ids
-    ):
-        """Replace the state in the context
-        """
-
-        # We need to make sure we wait for any ongoing fetching of state
-        # to complete so that the updated state doesn't get clobbered
-        if self._fetching_state_deferred:
-            yield make_deferred_yieldable(self._fetching_state_deferred)
-
-        self.state_group = state_group
-        self._prev_state_ids = prev_state_ids
-        self.prev_group = prev_group
-        self._current_state_ids = current_state_ids
-        self.delta_ids = delta_ids
-
-        # We need to ensure that that we've marked as having fetched the state
-        self._fetching_state_deferred = defer.succeed(None)
-
 
 def _encode_state_dict(state_dict):
     """Since dicts of (type, state_key) -> event_id cannot be serialized in
diff --git a/synapse/events/spamcheck.py b/synapse/events/spamcheck.py
index 129771f183..5a907718d6 100644
--- a/synapse/events/spamcheck.py
+++ b/synapse/events/spamcheck.py
@@ -1,5 +1,6 @@
 # -*- coding: utf-8 -*-
 # Copyright 2017 New Vector Ltd
+# Copyright 2019 The Matrix.org Foundation C.I.C.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -13,6 +14,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import inspect
+
+from synapse.spam_checker_api import SpamCheckerApi
+
 
 class SpamChecker(object):
     def __init__(self, hs):
@@ -26,7 +31,14 @@ class SpamChecker(object):
             pass
 
         if module is not None:
-            self.spam_checker = module(config=config)
+            # Older spam checkers don't accept the `api` argument, so we
+            # try and detect support.
+            spam_args = inspect.getfullargspec(module)
+            if "api" in spam_args.args:
+                api = SpamCheckerApi(hs)
+                self.spam_checker = module(config=config, api=api)
+            else:
+                self.spam_checker = module(config=config)
 
     def check_event_for_spam(self, event):
         """Checks if a given event is considered "spammy" by this server.
diff --git a/synapse/federation/federation_base.py b/synapse/federation/federation_base.py
index 223aace0d9..0e22183280 100644
--- a/synapse/federation/federation_base.py
+++ b/synapse/federation/federation_base.py
@@ -102,7 +102,7 @@ class FederationBase(object):
                     pass
 
             if not res:
-                logger.warn(
+                logger.warning(
                     "Failed to find copy of %s with valid signature", pdu.event_id
                 )
 
@@ -173,7 +173,7 @@ class FederationBase(object):
                     return redacted_event
 
                 if self.spam_checker.check_event_for_spam(pdu):
-                    logger.warn(
+                    logger.warning(
                         "Event contains spam, redacting %s: %s",
                         pdu.event_id,
                         pdu.get_pdu_json(),
@@ -185,7 +185,7 @@ class FederationBase(object):
         def errback(failure, pdu):
             failure.trap(SynapseError)
             with PreserveLoggingContext(ctx):
-                logger.warn(
+                logger.warning(
                     "Signature check failed for %s: %s",
                     pdu.event_id,
                     failure.getErrorMessage(),
diff --git a/synapse/federation/federation_client.py b/synapse/federation/federation_client.py
index 5b22a39b7f..545d719652 100644
--- a/synapse/federation/federation_client.py
+++ b/synapse/federation/federation_client.py
@@ -196,7 +196,7 @@ class FederationClient(FederationBase):
             dest, room_id, extremities, limit
         )
 
-        logger.debug("backfill transaction_data=%s", repr(transaction_data))
+        logger.debug("backfill transaction_data=%r", transaction_data)
 
         room_version = yield self.store.get_room_version(room_id)
         format_ver = room_version_to_event_format(room_version)
@@ -522,12 +522,12 @@ class FederationClient(FederationBase):
                 res = yield callback(destination)
                 return res
             except InvalidResponseError as e:
-                logger.warn("Failed to %s via %s: %s", description, destination, e)
+                logger.warning("Failed to %s via %s: %s", description, destination, e)
             except HttpResponseException as e:
                 if not 500 <= e.code < 600:
                     raise e.to_synapse_error()
                 else:
-                    logger.warn(
+                    logger.warning(
                         "Failed to %s via %s: %i %s",
                         description,
                         destination,
@@ -535,7 +535,9 @@ class FederationClient(FederationBase):
                         e.args[0],
                     )
             except Exception:
-                logger.warn("Failed to %s via %s", description, destination, exc_info=1)
+                logger.warning(
+                    "Failed to %s via %s", description, destination, exc_info=1
+                )
 
         raise SynapseError(502, "Failed to %s via any server" % (description,))
 
@@ -553,7 +555,7 @@ class FederationClient(FederationBase):
         Note that this does not append any events to any graphs.
 
         Args:
-            destinations (str): Candidate homeservers which are probably
+            destinations (Iterable[str]): Candidate homeservers which are probably
                 participating in the room.
             room_id (str): The room in which the event will happen.
             user_id (str): The user whose membership is being evented.
diff --git a/synapse/federation/federation_server.py b/synapse/federation/federation_server.py
index 5fc7c1d67b..d942d77a72 100644
--- a/synapse/federation/federation_server.py
+++ b/synapse/federation/federation_server.py
@@ -21,7 +21,6 @@ from six import iteritems
 from canonicaljson import json
 from prometheus_client import Counter
 
-from twisted.internet import defer
 from twisted.internet.abstract import isIPAddress
 from twisted.python import failure
 
@@ -86,14 +85,12 @@ class FederationServer(FederationBase):
         # come in waves.
         self._state_resp_cache = ResponseCache(hs, "state_resp", timeout_ms=30000)
 
-    @defer.inlineCallbacks
-    @log_function
-    def on_backfill_request(self, origin, room_id, versions, limit):
-        with (yield self._server_linearizer.queue((origin, room_id))):
+    async def on_backfill_request(self, origin, room_id, versions, limit):
+        with (await self._server_linearizer.queue((origin, room_id))):
             origin_host, _ = parse_server_name(origin)
-            yield self.check_server_matches_acl(origin_host, room_id)
+            await self.check_server_matches_acl(origin_host, room_id)
 
-            pdus = yield self.handler.on_backfill_request(
+            pdus = await self.handler.on_backfill_request(
                 origin, room_id, versions, limit
             )
 
@@ -101,9 +98,7 @@ class FederationServer(FederationBase):
 
         return 200, res
 
-    @defer.inlineCallbacks
-    @log_function
-    def on_incoming_transaction(self, origin, transaction_data):
+    async def on_incoming_transaction(self, origin, transaction_data):
         # keep this as early as possible to make the calculated origin ts as
         # accurate as possible.
         request_time = self._clock.time_msec()
@@ -118,18 +113,17 @@ class FederationServer(FederationBase):
         # use a linearizer to ensure that we don't process the same transaction
         # multiple times in parallel.
         with (
-            yield self._transaction_linearizer.queue(
+            await self._transaction_linearizer.queue(
                 (origin, transaction.transaction_id)
             )
         ):
-            result = yield self._handle_incoming_transaction(
+            result = await self._handle_incoming_transaction(
                 origin, transaction, request_time
             )
 
         return result
 
-    @defer.inlineCallbacks
-    def _handle_incoming_transaction(self, origin, transaction, request_time):
+    async def _handle_incoming_transaction(self, origin, transaction, request_time):
         """ Process an incoming transaction and return the HTTP response
 
         Args:
@@ -140,7 +134,7 @@ class FederationServer(FederationBase):
         Returns:
             Deferred[(int, object)]: http response code and body
         """
-        response = yield self.transaction_actions.have_responded(origin, transaction)
+        response = await self.transaction_actions.have_responded(origin, transaction)
 
         if response:
             logger.debug(
@@ -151,7 +145,7 @@ class FederationServer(FederationBase):
 
         logger.debug("[%s] Transaction is new", transaction.transaction_id)
 
-        # Reject if PDU count > 50 and EDU count > 100
+        # Reject if PDU count > 50 or EDU count > 100
         if len(transaction.pdus) > 50 or (
             hasattr(transaction, "edus") and len(transaction.edus) > 100
         ):
@@ -159,7 +153,7 @@ class FederationServer(FederationBase):
             logger.info("Transaction PDU or EDU count too large. Returning 400")
 
             response = {}
-            yield self.transaction_actions.set_response(
+            await self.transaction_actions.set_response(
                 origin, transaction, 400, response
             )
             return 400, response
@@ -195,7 +189,7 @@ class FederationServer(FederationBase):
                 continue
 
             try:
-                room_version = yield self.store.get_room_version(room_id)
+                room_version = await self.store.get_room_version(room_id)
             except NotFoundError:
                 logger.info("Ignoring PDU for unknown room_id: %s", room_id)
                 continue
@@ -221,13 +215,12 @@ class FederationServer(FederationBase):
         # require callouts to other servers to fetch missing events), but
         # impose a limit to avoid going too crazy with ram/cpu.
 
-        @defer.inlineCallbacks
-        def process_pdus_for_room(room_id):
+        async def process_pdus_for_room(room_id):
             logger.debug("Processing PDUs for %s", room_id)
             try:
-                yield self.check_server_matches_acl(origin_host, room_id)
+                await self.check_server_matches_acl(origin_host, room_id)
             except AuthError as e:
-                logger.warn("Ignoring PDUs for room %s from banned server", room_id)
+                logger.warning("Ignoring PDUs for room %s from banned server", room_id)
                 for pdu in pdus_by_room[room_id]:
                     event_id = pdu.event_id
                     pdu_results[event_id] = e.error_dict()
@@ -237,10 +230,10 @@ class FederationServer(FederationBase):
                 event_id = pdu.event_id
                 with nested_logging_context(event_id):
                     try:
-                        yield self._handle_received_pdu(origin, pdu)
+                        await self._handle_received_pdu(origin, pdu)
                         pdu_results[event_id] = {}
                     except FederationError as e:
-                        logger.warn("Error handling PDU %s: %s", event_id, e)
+                        logger.warning("Error handling PDU %s: %s", event_id, e)
                         pdu_results[event_id] = {"error": str(e)}
                     except Exception as e:
                         f = failure.Failure()
@@ -251,36 +244,33 @@ class FederationServer(FederationBase):
                             exc_info=(f.type, f.value, f.getTracebackObject()),
                         )
 
-        yield concurrently_execute(
+        await concurrently_execute(
             process_pdus_for_room, pdus_by_room.keys(), TRANSACTION_CONCURRENCY_LIMIT
         )
 
         if hasattr(transaction, "edus"):
             for edu in (Edu(**x) for x in transaction.edus):
-                yield self.received_edu(origin, edu.edu_type, edu.content)
+                await self.received_edu(origin, edu.edu_type, edu.content)
 
         response = {"pdus": pdu_results}
 
         logger.debug("Returning: %s", str(response))
 
-        yield self.transaction_actions.set_response(origin, transaction, 200, response)
+        await self.transaction_actions.set_response(origin, transaction, 200, response)
         return 200, response
 
-    @defer.inlineCallbacks
-    def received_edu(self, origin, edu_type, content):
+    async def received_edu(self, origin, edu_type, content):
         received_edus_counter.inc()
-        yield self.registry.on_edu(edu_type, origin, content)
+        await self.registry.on_edu(edu_type, origin, content)
 
-    @defer.inlineCallbacks
-    @log_function
-    def on_context_state_request(self, origin, room_id, event_id):
+    async def on_context_state_request(self, origin, room_id, event_id):
         if not event_id:
             raise NotImplementedError("Specify an event")
 
         origin_host, _ = parse_server_name(origin)
-        yield self.check_server_matches_acl(origin_host, room_id)
+        await self.check_server_matches_acl(origin_host, room_id)
 
-        in_room = yield self.auth.check_host_in_room(room_id, origin)
+        in_room = await self.auth.check_host_in_room(room_id, origin)
         if not in_room:
             raise AuthError(403, "Host not in room.")
 
@@ -289,8 +279,8 @@ class FederationServer(FederationBase):
         # in the cache so we could return it without waiting for the linearizer
         # - but that's non-trivial to get right, and anyway somewhat defeats
         # the point of the linearizer.
-        with (yield self._server_linearizer.queue((origin, room_id))):
-            resp = yield self._state_resp_cache.wrap(
+        with (await self._server_linearizer.queue((origin, room_id))):
+            resp = await self._state_resp_cache.wrap(
                 (room_id, event_id),
                 self._on_context_state_request_compute,
                 room_id,
@@ -299,65 +289,60 @@ class FederationServer(FederationBase):
 
         return 200, resp
 
-    @defer.inlineCallbacks
-    def on_state_ids_request(self, origin, room_id, event_id):
+    async def on_state_ids_request(self, origin, room_id, event_id):
         if not event_id:
             raise NotImplementedError("Specify an event")
 
         origin_host, _ = parse_server_name(origin)
-        yield self.check_server_matches_acl(origin_host, room_id)
+        await self.check_server_matches_acl(origin_host, room_id)
 
-        in_room = yield self.auth.check_host_in_room(room_id, origin)
+        in_room = await self.auth.check_host_in_room(room_id, origin)
         if not in_room:
             raise AuthError(403, "Host not in room.")
 
-        state_ids = yield self.handler.get_state_ids_for_pdu(room_id, event_id)
-        auth_chain_ids = yield self.store.get_auth_chain_ids(state_ids)
+        state_ids = await self.handler.get_state_ids_for_pdu(room_id, event_id)
+        auth_chain_ids = await self.store.get_auth_chain_ids(state_ids)
 
         return 200, {"pdu_ids": state_ids, "auth_chain_ids": auth_chain_ids}
 
-    @defer.inlineCallbacks
-    def _on_context_state_request_compute(self, room_id, event_id):
-        pdus = yield self.handler.get_state_for_pdu(room_id, event_id)
-        auth_chain = yield self.store.get_auth_chain([pdu.event_id for pdu in pdus])
+    async def _on_context_state_request_compute(self, room_id, event_id):
+        pdus = await self.handler.get_state_for_pdu(room_id, event_id)
+        auth_chain = await self.store.get_auth_chain([pdu.event_id for pdu in pdus])
 
         return {
             "pdus": [pdu.get_pdu_json() for pdu in pdus],
             "auth_chain": [pdu.get_pdu_json() for pdu in auth_chain],
         }
 
-    @defer.inlineCallbacks
-    @log_function
-    def on_pdu_request(self, origin, event_id):
-        pdu = yield self.handler.get_persisted_pdu(origin, event_id)
+    async def on_pdu_request(self, origin, event_id):
+        pdu = await self.handler.get_persisted_pdu(origin, event_id)
 
         if pdu:
             return 200, self._transaction_from_pdus([pdu]).get_dict()
         else:
             return 404, ""
 
-    @defer.inlineCallbacks
-    def on_query_request(self, query_type, args):
+    async def on_query_request(self, query_type, args):
         received_queries_counter.labels(query_type).inc()
-        resp = yield self.registry.on_query(query_type, args)
+        resp = await self.registry.on_query(query_type, args)
         return 200, resp
 
-    @defer.inlineCallbacks
-    def on_make_join_request(self, origin, room_id, user_id, supported_versions):
+    async def on_make_join_request(self, origin, room_id, user_id, supported_versions):
         origin_host, _ = parse_server_name(origin)
-        yield self.check_server_matches_acl(origin_host, room_id)
+        await self.check_server_matches_acl(origin_host, room_id)
 
-        room_version = yield self.store.get_room_version(room_id)
+        room_version = await self.store.get_room_version(room_id)
         if room_version not in supported_versions:
-            logger.warn("Room version %s not in %s", room_version, supported_versions)
+            logger.warning(
+                "Room version %s not in %s", room_version, supported_versions
+            )
             raise IncompatibleRoomVersionError(room_version=room_version)
 
-        pdu = yield self.handler.on_make_join_request(origin, room_id, user_id)
+        pdu = await self.handler.on_make_join_request(origin, room_id, user_id)
         time_now = self._clock.time_msec()
         return {"event": pdu.get_pdu_json(time_now), "room_version": room_version}
 
-    @defer.inlineCallbacks
-    def on_invite_request(self, origin, content, room_version):
+    async def on_invite_request(self, origin, content, room_version):
         if room_version not in KNOWN_ROOM_VERSIONS:
             raise SynapseError(
                 400,
@@ -369,28 +354,27 @@ class FederationServer(FederationBase):
 
         pdu = event_from_pdu_json(content, format_ver)
         origin_host, _ = parse_server_name(origin)
-        yield self.check_server_matches_acl(origin_host, pdu.room_id)
-        pdu = yield self._check_sigs_and_hash(room_version, pdu)
-        ret_pdu = yield self.handler.on_invite_request(origin, pdu)
+        await self.check_server_matches_acl(origin_host, pdu.room_id)
+        pdu = await self._check_sigs_and_hash(room_version, pdu)
+        ret_pdu = await self.handler.on_invite_request(origin, pdu)
         time_now = self._clock.time_msec()
         return {"event": ret_pdu.get_pdu_json(time_now)}
 
-    @defer.inlineCallbacks
-    def on_send_join_request(self, origin, content, room_id):
+    async def on_send_join_request(self, origin, content, room_id):
         logger.debug("on_send_join_request: content: %s", content)
 
-        room_version = yield self.store.get_room_version(room_id)
+        room_version = await self.store.get_room_version(room_id)
         format_ver = room_version_to_event_format(room_version)
         pdu = event_from_pdu_json(content, format_ver)
 
         origin_host, _ = parse_server_name(origin)
-        yield self.check_server_matches_acl(origin_host, pdu.room_id)
+        await self.check_server_matches_acl(origin_host, pdu.room_id)
 
         logger.debug("on_send_join_request: pdu sigs: %s", pdu.signatures)
 
-        pdu = yield self._check_sigs_and_hash(room_version, pdu)
+        pdu = await self._check_sigs_and_hash(room_version, pdu)
 
-        res_pdus = yield self.handler.on_send_join_request(origin, pdu)
+        res_pdus = await self.handler.on_send_join_request(origin, pdu)
         time_now = self._clock.time_msec()
         return (
             200,
@@ -402,48 +386,44 @@ class FederationServer(FederationBase):
             },
         )
 
-    @defer.inlineCallbacks
-    def on_make_leave_request(self, origin, room_id, user_id):
+    async def on_make_leave_request(self, origin, room_id, user_id):
         origin_host, _ = parse_server_name(origin)
-        yield self.check_server_matches_acl(origin_host, room_id)
-        pdu = yield self.handler.on_make_leave_request(origin, room_id, user_id)
+        await self.check_server_matches_acl(origin_host, room_id)
+        pdu = await self.handler.on_make_leave_request(origin, room_id, user_id)
 
-        room_version = yield self.store.get_room_version(room_id)
+        room_version = await self.store.get_room_version(room_id)
 
         time_now = self._clock.time_msec()
         return {"event": pdu.get_pdu_json(time_now), "room_version": room_version}
 
-    @defer.inlineCallbacks
-    def on_send_leave_request(self, origin, content, room_id):
+    async def on_send_leave_request(self, origin, content, room_id):
         logger.debug("on_send_leave_request: content: %s", content)
 
-        room_version = yield self.store.get_room_version(room_id)
+        room_version = await self.store.get_room_version(room_id)
         format_ver = room_version_to_event_format(room_version)
         pdu = event_from_pdu_json(content, format_ver)
 
         origin_host, _ = parse_server_name(origin)
-        yield self.check_server_matches_acl(origin_host, pdu.room_id)
+        await self.check_server_matches_acl(origin_host, pdu.room_id)
 
         logger.debug("on_send_leave_request: pdu sigs: %s", pdu.signatures)
 
-        pdu = yield self._check_sigs_and_hash(room_version, pdu)
+        pdu = await self._check_sigs_and_hash(room_version, pdu)
 
-        yield self.handler.on_send_leave_request(origin, pdu)
+        await self.handler.on_send_leave_request(origin, pdu)
         return 200, {}
 
-    @defer.inlineCallbacks
-    def on_event_auth(self, origin, room_id, event_id):
-        with (yield self._server_linearizer.queue((origin, room_id))):
+    async def on_event_auth(self, origin, room_id, event_id):
+        with (await self._server_linearizer.queue((origin, room_id))):
             origin_host, _ = parse_server_name(origin)
-            yield self.check_server_matches_acl(origin_host, room_id)
+            await self.check_server_matches_acl(origin_host, room_id)
 
             time_now = self._clock.time_msec()
-            auth_pdus = yield self.handler.on_event_auth(event_id)
+            auth_pdus = await self.handler.on_event_auth(event_id)
             res = {"auth_chain": [a.get_pdu_json(time_now) for a in auth_pdus]}
         return 200, res
 
-    @defer.inlineCallbacks
-    def on_query_auth_request(self, origin, content, room_id, event_id):
+    async def on_query_auth_request(self, origin, content, room_id, event_id):
         """
         Content is a dict with keys::
             auth_chain (list): A list of events that give the auth chain.
@@ -462,22 +442,22 @@ class FederationServer(FederationBase):
         Returns:
             Deferred: Results in `dict` with the same format as `content`
         """
-        with (yield self._server_linearizer.queue((origin, room_id))):
+        with (await self._server_linearizer.queue((origin, room_id))):
             origin_host, _ = parse_server_name(origin)
-            yield self.check_server_matches_acl(origin_host, room_id)
+            await self.check_server_matches_acl(origin_host, room_id)
 
-            room_version = yield self.store.get_room_version(room_id)
+            room_version = await self.store.get_room_version(room_id)
             format_ver = room_version_to_event_format(room_version)
 
             auth_chain = [
                 event_from_pdu_json(e, format_ver) for e in content["auth_chain"]
             ]
 
-            signed_auth = yield self._check_sigs_and_hash_and_fetch(
+            signed_auth = await self._check_sigs_and_hash_and_fetch(
                 origin, auth_chain, outlier=True, room_version=room_version
             )
 
-            ret = yield self.handler.on_query_auth(
+            ret = await self.handler.on_query_auth(
                 origin,
                 event_id,
                 room_id,
@@ -503,16 +483,14 @@ class FederationServer(FederationBase):
         return self.on_query_request("user_devices", user_id)
 
     @trace
-    @defer.inlineCallbacks
-    @log_function
-    def on_claim_client_keys(self, origin, content):
+    async def on_claim_client_keys(self, origin, content):
         query = []
         for user_id, device_keys in content.get("one_time_keys", {}).items():
             for device_id, algorithm in device_keys.items():
                 query.append((user_id, device_id, algorithm))
 
         log_kv({"message": "Claiming one time keys.", "user, device pairs": query})
-        results = yield self.store.claim_e2e_one_time_keys(query)
+        results = await self.store.claim_e2e_one_time_keys(query)
 
         json_result = {}
         for user_id, device_keys in results.items():
@@ -536,14 +514,12 @@ class FederationServer(FederationBase):
 
         return {"one_time_keys": json_result}
 
-    @defer.inlineCallbacks
-    @log_function
-    def on_get_missing_events(
+    async def on_get_missing_events(
         self, origin, room_id, earliest_events, latest_events, limit
     ):
-        with (yield self._server_linearizer.queue((origin, room_id))):
+        with (await self._server_linearizer.queue((origin, room_id))):
             origin_host, _ = parse_server_name(origin)
-            yield self.check_server_matches_acl(origin_host, room_id)
+            await self.check_server_matches_acl(origin_host, room_id)
 
             logger.info(
                 "on_get_missing_events: earliest_events: %r, latest_events: %r,"
@@ -553,7 +529,7 @@ class FederationServer(FederationBase):
                 limit,
             )
 
-            missing_events = yield self.handler.on_get_missing_events(
+            missing_events = await self.handler.on_get_missing_events(
                 origin, room_id, earliest_events, latest_events, limit
             )
 
@@ -586,8 +562,7 @@ class FederationServer(FederationBase):
             destination=None,
         )
 
-    @defer.inlineCallbacks
-    def _handle_received_pdu(self, origin, pdu):
+    async def _handle_received_pdu(self, origin, pdu):
         """ Process a PDU received in a federation /send/ transaction.
 
         If the event is invalid, then this method throws a FederationError.
@@ -640,37 +615,34 @@ class FederationServer(FederationBase):
                 logger.info("Accepting join PDU %s from %s", pdu.event_id, origin)
 
         # We've already checked that we know the room version by this point
-        room_version = yield self.store.get_room_version(pdu.room_id)
+        room_version = await self.store.get_room_version(pdu.room_id)
 
         # Check signature.
         try:
-            pdu = yield self._check_sigs_and_hash(room_version, pdu)
+            pdu = await self._check_sigs_and_hash(room_version, pdu)
         except SynapseError as e:
             raise FederationError("ERROR", e.code, e.msg, affected=pdu.event_id)
 
-        yield self.handler.on_receive_pdu(origin, pdu, sent_to_us_directly=True)
+        await self.handler.on_receive_pdu(origin, pdu, sent_to_us_directly=True)
 
     def __str__(self):
         return "<ReplicationLayer(%s)>" % self.server_name
 
-    @defer.inlineCallbacks
-    def exchange_third_party_invite(
+    async def exchange_third_party_invite(
         self, sender_user_id, target_user_id, room_id, signed
     ):
-        ret = yield self.handler.exchange_third_party_invite(
+        ret = await self.handler.exchange_third_party_invite(
             sender_user_id, target_user_id, room_id, signed
         )
         return ret
 
-    @defer.inlineCallbacks
-    def on_exchange_third_party_invite_request(self, room_id, event_dict):
-        ret = yield self.handler.on_exchange_third_party_invite_request(
+    async def on_exchange_third_party_invite_request(self, room_id, event_dict):
+        ret = await self.handler.on_exchange_third_party_invite_request(
             room_id, event_dict
         )
         return ret
 
-    @defer.inlineCallbacks
-    def check_server_matches_acl(self, server_name, room_id):
+    async def check_server_matches_acl(self, server_name, room_id):
         """Check if the given server is allowed by the server ACLs in the room
 
         Args:
@@ -680,13 +652,13 @@ class FederationServer(FederationBase):
         Raises:
             AuthError if the server does not match the ACL
         """
-        state_ids = yield self.store.get_current_state_ids(room_id)
+        state_ids = await self.store.get_current_state_ids(room_id)
         acl_event_id = state_ids.get((EventTypes.ServerACL, ""))
 
         if not acl_event_id:
             return
 
-        acl_event = yield self.store.get_event(acl_event_id)
+        acl_event = await self.store.get_event(acl_event_id)
         if server_matches_acl_event(server_name, acl_event):
             return
 
@@ -709,7 +681,7 @@ def server_matches_acl_event(server_name, acl_event):
     # server name is a literal IP
     allow_ip_literals = acl_event.content.get("allow_ip_literals", True)
     if not isinstance(allow_ip_literals, bool):
-        logger.warn("Ignorning non-bool allow_ip_literals flag")
+        logger.warning("Ignorning non-bool allow_ip_literals flag")
         allow_ip_literals = True
     if not allow_ip_literals:
         # check for ipv6 literals. These start with '['.
@@ -723,7 +695,7 @@ def server_matches_acl_event(server_name, acl_event):
     # next,  check the deny list
     deny = acl_event.content.get("deny", [])
     if not isinstance(deny, (list, tuple)):
-        logger.warn("Ignorning non-list deny ACL %s", deny)
+        logger.warning("Ignorning non-list deny ACL %s", deny)
         deny = []
     for e in deny:
         if _acl_entry_matches(server_name, e):
@@ -733,7 +705,7 @@ def server_matches_acl_event(server_name, acl_event):
     # then the allow list.
     allow = acl_event.content.get("allow", [])
     if not isinstance(allow, (list, tuple)):
-        logger.warn("Ignorning non-list allow ACL %s", allow)
+        logger.warning("Ignorning non-list allow ACL %s", allow)
         allow = []
     for e in allow:
         if _acl_entry_matches(server_name, e):
@@ -747,7 +719,7 @@ def server_matches_acl_event(server_name, acl_event):
 
 def _acl_entry_matches(server_name, acl_entry):
     if not isinstance(acl_entry, six.string_types):
-        logger.warn(
+        logger.warning(
             "Ignoring non-str ACL entry '%s' (is %s)", acl_entry, type(acl_entry)
         )
         return False
@@ -799,15 +771,14 @@ class FederationHandlerRegistry(object):
 
         self.query_handlers[query_type] = handler
 
-    @defer.inlineCallbacks
-    def on_edu(self, edu_type, origin, content):
+    async def on_edu(self, edu_type, origin, content):
         handler = self.edu_handlers.get(edu_type)
         if not handler:
-            logger.warn("No handler registered for EDU type %s", edu_type)
+            logger.warning("No handler registered for EDU type %s", edu_type)
 
         with start_active_span_from_edu(content, "handle_edu"):
             try:
-                yield handler(origin, content)
+                await handler(origin, content)
             except SynapseError as e:
                 logger.info("Failed to handle edu %r: %r", edu_type, e)
             except Exception:
@@ -816,7 +787,7 @@ class FederationHandlerRegistry(object):
     def on_query(self, query_type, args):
         handler = self.query_handlers.get(query_type)
         if not handler:
-            logger.warn("No handler registered for query type %s", query_type)
+            logger.warning("No handler registered for query type %s", query_type)
             raise NotFoundError("No handler for Query type '%s'" % (query_type,))
 
         return handler(args)
@@ -840,7 +811,7 @@ class ReplicationFederationHandlerRegistry(FederationHandlerRegistry):
 
         super(ReplicationFederationHandlerRegistry, self).__init__()
 
-    def on_edu(self, edu_type, origin, content):
+    async def on_edu(self, edu_type, origin, content):
         """Overrides FederationHandlerRegistry
         """
         if not self.config.use_presence and edu_type == "m.presence":
@@ -848,17 +819,17 @@ class ReplicationFederationHandlerRegistry(FederationHandlerRegistry):
 
         handler = self.edu_handlers.get(edu_type)
         if handler:
-            return super(ReplicationFederationHandlerRegistry, self).on_edu(
+            return await super(ReplicationFederationHandlerRegistry, self).on_edu(
                 edu_type, origin, content
             )
 
-        return self._send_edu(edu_type=edu_type, origin=origin, content=content)
+        return await self._send_edu(edu_type=edu_type, origin=origin, content=content)
 
-    def on_query(self, query_type, args):
+    async def on_query(self, query_type, args):
         """Overrides FederationHandlerRegistry
         """
         handler = self.query_handlers.get(query_type)
         if handler:
-            return handler(args)
+            return await handler(args)
 
-        return self._get_query_client(query_type=query_type, args=args)
+        return await self._get_query_client(query_type=query_type, args=args)
diff --git a/synapse/federation/send_queue.py b/synapse/federation/send_queue.py
index 454456a52d..ced4925a98 100644
--- a/synapse/federation/send_queue.py
+++ b/synapse/federation/send_queue.py
@@ -36,6 +36,8 @@ from six import iteritems
 
 from sortedcontainers import SortedDict
 
+from twisted.internet import defer
+
 from synapse.metrics import LaterGauge
 from synapse.storage.presence import UserPresenceState
 from synapse.util.metrics import Measure
@@ -212,7 +214,7 @@ class FederationRemoteSendQueue(object):
             receipt (synapse.types.ReadReceipt):
         """
         # nothing to do here: the replication listener will handle it.
-        pass
+        return defer.succeed(None)
 
     def send_presence(self, states):
         """As per FederationSender
diff --git a/synapse/federation/sender/per_destination_queue.py b/synapse/federation/sender/per_destination_queue.py
index cc75c39476..a5b36b1827 100644
--- a/synapse/federation/sender/per_destination_queue.py
+++ b/synapse/federation/sender/per_destination_queue.py
@@ -192,15 +192,16 @@ class PerDestinationQueue(object):
                 # We have to keep 2 free slots for presence and rr_edus
                 limit = MAX_EDUS_PER_TRANSACTION - 2
 
-                device_update_edus, dev_list_id = (
-                    yield self._get_device_update_edus(limit)
+                device_update_edus, dev_list_id = yield self._get_device_update_edus(
+                    limit
                 )
 
                 limit -= len(device_update_edus)
 
-                to_device_edus, device_stream_id = (
-                    yield self._get_to_device_message_edus(limit)
-                )
+                (
+                    to_device_edus,
+                    device_stream_id,
+                ) = yield self._get_to_device_message_edus(limit)
 
                 pending_edus = device_update_edus + to_device_edus
 
@@ -359,20 +360,20 @@ class PerDestinationQueue(object):
         last_device_list = self._last_device_list_stream_id
 
         # Retrieve list of new device updates to send to the destination
-        now_stream_id, results = yield self._store.get_devices_by_remote(
+        now_stream_id, results = yield self._store.get_device_updates_by_remote(
             self._destination, last_device_list, limit=limit
         )
         edus = [
             Edu(
                 origin=self._server_name,
                 destination=self._destination,
-                edu_type="m.device_list_update",
+                edu_type=edu_type,
                 content=content,
             )
-            for content in results
+            for (edu_type, content) in results
         ]
 
-        assert len(edus) <= limit, "get_devices_by_remote returned too many EDUs"
+        assert len(edus) <= limit, "get_device_updates_by_remote returned too many EDUs"
 
         return (edus, now_stream_id)
 
diff --git a/synapse/federation/sender/transaction_manager.py b/synapse/federation/sender/transaction_manager.py
index 5b6c79c51a..67b3e1ab6e 100644
--- a/synapse/federation/sender/transaction_manager.py
+++ b/synapse/federation/sender/transaction_manager.py
@@ -146,7 +146,7 @@ class TransactionManager(object):
             if code == 200:
                 for e_id, r in response.get("pdus", {}).items():
                     if "error" in r:
-                        logger.warn(
+                        logger.warning(
                             "TX [%s] {%s} Remote returned error for %s: %s",
                             destination,
                             txn_id,
@@ -155,7 +155,7 @@ class TransactionManager(object):
                         )
             else:
                 for p in pdus:
-                    logger.warn(
+                    logger.warning(
                         "TX [%s] {%s} Failed to send event %s",
                         destination,
                         txn_id,
diff --git a/synapse/federation/transport/client.py b/synapse/federation/transport/client.py
index 7b18408144..920fa86853 100644
--- a/synapse/federation/transport/client.py
+++ b/synapse/federation/transport/client.py
@@ -122,10 +122,10 @@ class TransportLayerClient(object):
             Deferred: Results in a dict received from the remote homeserver.
         """
         logger.debug(
-            "backfill dest=%s, room_id=%s, event_tuples=%s, limit=%s",
+            "backfill dest=%s, room_id=%s, event_tuples=%r, limit=%s",
             destination,
             room_id,
-            repr(event_tuples),
+            event_tuples,
             str(limit),
         )
 
diff --git a/synapse/federation/transport/server.py b/synapse/federation/transport/server.py
index 0f16f21c2d..d6c23f22bd 100644
--- a/synapse/federation/transport/server.py
+++ b/synapse/federation/transport/server.py
@@ -202,7 +202,7 @@ def _parse_auth_header(header_bytes):
         sig = strip_quotes(param_dict["sig"])
         return origin, key, sig
     except Exception as e:
-        logger.warn(
+        logger.warning(
             "Error parsing auth header '%s': %s",
             header_bytes.decode("ascii", "replace"),
             e,
@@ -287,10 +287,12 @@ class BaseFederationServlet(object):
             except NoAuthenticationError:
                 origin = None
                 if self.REQUIRE_AUTH:
-                    logger.warn("authenticate_request failed: missing authentication")
+                    logger.warning(
+                        "authenticate_request failed: missing authentication"
+                    )
                     raise
             except Exception as e:
-                logger.warn("authenticate_request failed: %s", e)
+                logger.warning("authenticate_request failed: %s", e)
                 raise
 
             request_tags = {
diff --git a/synapse/groups/attestations.py b/synapse/groups/attestations.py
index dfd7ae041b..d950a8b246 100644
--- a/synapse/groups/attestations.py
+++ b/synapse/groups/attestations.py
@@ -181,7 +181,7 @@ class GroupAttestionRenewer(object):
                 elif not self.is_mine_id(user_id):
                     destination = get_domain_from_id(user_id)
                 else:
-                    logger.warn(
+                    logger.warning(
                         "Incorrectly trying to do attestations for user: %r in %r",
                         user_id,
                         group_id,
diff --git a/synapse/groups/groups_server.py b/synapse/groups/groups_server.py
index 8f10b6adbb..29e8ffc295 100644
--- a/synapse/groups/groups_server.py
+++ b/synapse/groups/groups_server.py
@@ -488,7 +488,7 @@ class GroupsServerHandler(object):
                 profile = yield self.profile_handler.get_profile_from_cache(user_id)
                 user_profile.update(profile)
             except Exception as e:
-                logger.warn("Error getting profile for %s: %s", user_id, e)
+                logger.warning("Error getting profile for %s: %s", user_id, e)
             user_profiles.append(user_profile)
 
         return {"chunk": user_profiles, "total_user_count_estimate": len(invited_users)}
diff --git a/synapse/handlers/account_data.py b/synapse/handlers/account_data.py
index 38bc67191c..2d7e6df6e4 100644
--- a/synapse/handlers/account_data.py
+++ b/synapse/handlers/account_data.py
@@ -38,9 +38,10 @@ class AccountDataEventSource(object):
                 {"type": "m.tag", "content": {"tags": room_tags}, "room_id": room_id}
             )
 
-        account_data, room_account_data = (
-            yield self.store.get_updated_account_data_for_user(user_id, last_stream_id)
-        )
+        (
+            account_data,
+            room_account_data,
+        ) = yield self.store.get_updated_account_data_for_user(user_id, last_stream_id)
 
         for account_data_type, content in account_data.items():
             results.append({"type": account_data_type, "content": content})
diff --git a/synapse/handlers/admin.py b/synapse/handlers/admin.py
index 1a87b58838..6407d56f8e 100644
--- a/synapse/handlers/admin.py
+++ b/synapse/handlers/admin.py
@@ -30,6 +30,9 @@ class AdminHandler(BaseHandler):
     def __init__(self, hs):
         super(AdminHandler, self).__init__(hs)
 
+        self.storage = hs.get_storage()
+        self.state_store = self.storage.state
+
     @defer.inlineCallbacks
     def get_whois(self, user):
         connections = []
@@ -205,7 +208,7 @@ class AdminHandler(BaseHandler):
 
                 from_key = events[-1].internal_metadata.after
 
-                events = yield filter_events_for_client(self.store, user_id, events)
+                events = yield filter_events_for_client(self.storage, user_id, events)
 
                 writer.write_events(room_id, events)
 
@@ -241,7 +244,7 @@ class AdminHandler(BaseHandler):
             for event_id in extremities:
                 if not event_to_unseen_prevs[event_id]:
                     continue
-                state = yield self.store.get_state_for_event(event_id)
+                state = yield self.state_store.get_state_for_event(event_id)
                 writer.write_state(room_id, event_id, state)
 
         return writer.finished()
diff --git a/synapse/handlers/appservice.py b/synapse/handlers/appservice.py
index 3e9b298154..fe62f78e67 100644
--- a/synapse/handlers/appservice.py
+++ b/synapse/handlers/appservice.py
@@ -73,7 +73,10 @@ class ApplicationServicesHandler(object):
             try:
                 limit = 100
                 while True:
-                    upper_bound, events = yield self.store.get_new_events_for_appservice(
+                    (
+                        upper_bound,
+                        events,
+                    ) = yield self.store.get_new_events_for_appservice(
                         self.current_max, limit
                     )
 
diff --git a/synapse/handlers/auth.py b/synapse/handlers/auth.py
index 333eb30625..7a0f54ca24 100644
--- a/synapse/handlers/auth.py
+++ b/synapse/handlers/auth.py
@@ -525,7 +525,7 @@ class AuthHandler(BaseHandler):
 
         result = None
         if not user_infos:
-            logger.warn("Attempted to login as %s but they do not exist", user_id)
+            logger.warning("Attempted to login as %s but they do not exist", user_id)
         elif len(user_infos) == 1:
             # a single match (possibly not exact)
             result = user_infos.popitem()
@@ -534,7 +534,7 @@ class AuthHandler(BaseHandler):
             result = (user_id, user_infos[user_id])
         else:
             # multiple matches, none of them exact
-            logger.warn(
+            logger.warning(
                 "Attempted to login as %s but it matches more than one user "
                 "inexactly: %r",
                 user_id,
@@ -728,7 +728,7 @@ class AuthHandler(BaseHandler):
 
         result = yield self.validate_hash(password, password_hash)
         if not result:
-            logger.warn("Failed password login for user %s", user_id)
+            logger.warning("Failed password login for user %s", user_id)
             return None
         return user_id
 
diff --git a/synapse/handlers/device.py b/synapse/handlers/device.py
index 5f23ee4488..26ef5e150c 100644
--- a/synapse/handlers/device.py
+++ b/synapse/handlers/device.py
@@ -46,6 +46,7 @@ class DeviceWorkerHandler(BaseHandler):
 
         self.hs = hs
         self.state = hs.get_state_handler()
+        self.state_store = hs.get_storage().state
         self._auth_handler = hs.get_auth_handler()
 
     @trace
@@ -178,7 +179,7 @@ class DeviceWorkerHandler(BaseHandler):
                 continue
 
             # mapping from event_id -> state_dict
-            prev_state_ids = yield self.store.get_state_ids_for_events(event_ids)
+            prev_state_ids = yield self.state_store.get_state_ids_for_events(event_ids)
 
             # Check if we've joined the room? If so we just blindly add all the users to
             # the "possibly changed" users.
@@ -458,7 +459,18 @@ class DeviceHandler(DeviceWorkerHandler):
     @defer.inlineCallbacks
     def on_federation_query_user_devices(self, user_id):
         stream_id, devices = yield self.store.get_devices_with_keys_by_user(user_id)
-        return {"user_id": user_id, "stream_id": stream_id, "devices": devices}
+        master_key = yield self.store.get_e2e_cross_signing_key(user_id, "master")
+        self_signing_key = yield self.store.get_e2e_cross_signing_key(
+            user_id, "self_signing"
+        )
+
+        return {
+            "user_id": user_id,
+            "stream_id": stream_id,
+            "devices": devices,
+            "master_key": master_key,
+            "self_signing_key": self_signing_key,
+        }
 
     @defer.inlineCallbacks
     def user_left_room(self, user, room_id):
@@ -656,7 +668,7 @@ class DeviceListUpdater(object):
         except (NotRetryingDestination, RequestSendFailed, HttpResponseException):
             # TODO: Remember that we are now out of sync and try again
             # later
-            logger.warn("Failed to handle device list update for %s", user_id)
+            logger.warning("Failed to handle device list update for %s", user_id)
             # We abort on exceptions rather than accepting the update
             # as otherwise synapse will 'forget' that its device list
             # is out of date. If we bail then we will retry the resync
@@ -694,7 +706,7 @@ class DeviceListUpdater(object):
         # up on storing the total list of devices and only handle the
         # delta instead.
         if len(devices) > 1000:
-            logger.warn(
+            logger.warning(
                 "Ignoring device list snapshot for %s as it has >1K devs (%d)",
                 user_id,
                 len(devices),
diff --git a/synapse/handlers/devicemessage.py b/synapse/handlers/devicemessage.py
index 0043cbea17..73b9e120f5 100644
--- a/synapse/handlers/devicemessage.py
+++ b/synapse/handlers/devicemessage.py
@@ -52,7 +52,7 @@ class DeviceMessageHandler(object):
         local_messages = {}
         sender_user_id = content["sender"]
         if origin != get_domain_from_id(sender_user_id):
-            logger.warn(
+            logger.warning(
                 "Dropping device message from %r with spoofed sender %r",
                 origin,
                 sender_user_id,
diff --git a/synapse/handlers/directory.py b/synapse/handlers/directory.py
index 526379c6f7..c4632f8984 100644
--- a/synapse/handlers/directory.py
+++ b/synapse/handlers/directory.py
@@ -250,7 +250,7 @@ class DirectoryHandler(BaseHandler):
                     ignore_backoff=True,
                 )
             except CodeMessageException as e:
-                logging.warn("Error retrieving alias")
+                logging.warning("Error retrieving alias")
                 if e.code == 404:
                     result = None
                 else:
diff --git a/synapse/handlers/e2e_keys.py b/synapse/handlers/e2e_keys.py
index 5ea54f60be..f09a0b73c8 100644
--- a/synapse/handlers/e2e_keys.py
+++ b/synapse/handlers/e2e_keys.py
@@ -36,6 +36,8 @@ from synapse.types import (
     get_verify_key_from_cross_signing_key,
 )
 from synapse.util import unwrapFirstError
+from synapse.util.async_helpers import Linearizer
+from synapse.util.caches.expiringcache import ExpiringCache
 from synapse.util.retryutils import NotRetryingDestination
 
 logger = logging.getLogger(__name__)
@@ -49,10 +51,19 @@ class E2eKeysHandler(object):
         self.is_mine = hs.is_mine
         self.clock = hs.get_clock()
 
+        self._edu_updater = SigningKeyEduUpdater(hs, self)
+
+        federation_registry = hs.get_federation_registry()
+
+        # FIXME: switch to m.signing_key_update when MSC1756 is merged into the spec
+        federation_registry.register_edu_handler(
+            "org.matrix.signing_key_update",
+            self._edu_updater.incoming_signing_key_update,
+        )
         # doesn't really work as part of the generic query API, because the
         # query request requires an object POST, but we abuse the
         # "query handler" interface.
-        hs.get_federation_registry().register_query_handler(
+        federation_registry.register_query_handler(
             "client_keys", self.on_federation_query_client_keys
         )
 
@@ -119,9 +130,10 @@ class E2eKeysHandler(object):
                 else:
                     query_list.append((user_id, None))
 
-            user_ids_not_in_cache, remote_results = (
-                yield self.store.get_user_devices_from_cache(query_list)
-            )
+            (
+                user_ids_not_in_cache,
+                remote_results,
+            ) = yield self.store.get_user_devices_from_cache(query_list)
             for user_id, devices in iteritems(remote_results):
                 user_devices = results.setdefault(user_id, {})
                 for device_id, device in iteritems(devices):
@@ -207,13 +219,15 @@ class E2eKeysHandler(object):
                     if user_id in destination_query:
                         results[user_id] = keys
 
-                for user_id, key in remote_result["master_keys"].items():
-                    if user_id in destination_query:
-                        cross_signing_keys["master_keys"][user_id] = key
+                if "master_keys" in remote_result:
+                    for user_id, key in remote_result["master_keys"].items():
+                        if user_id in destination_query:
+                            cross_signing_keys["master_keys"][user_id] = key
 
-                for user_id, key in remote_result["self_signing_keys"].items():
-                    if user_id in destination_query:
-                        cross_signing_keys["self_signing_keys"][user_id] = key
+                if "self_signing_keys" in remote_result:
+                    for user_id, key in remote_result["self_signing_keys"].items():
+                        if user_id in destination_query:
+                            cross_signing_keys["self_signing_keys"][user_id] = key
 
             except Exception as e:
                 failure = _exception_to_failure(e)
@@ -251,7 +265,7 @@ class E2eKeysHandler(object):
 
         Returns:
             defer.Deferred[dict[str, dict[str, dict]]]: map from
-                (master|self_signing|user_signing) -> user_id -> key
+                (master_keys|self_signing_keys|user_signing_keys) -> user_id -> key
         """
         master_keys = {}
         self_signing_keys = {}
@@ -343,7 +357,16 @@ class E2eKeysHandler(object):
         """
         device_keys_query = query_body.get("device_keys", {})
         res = yield self.query_local_devices(device_keys_query)
-        return {"device_keys": res}
+        ret = {"device_keys": res}
+
+        # add in the cross-signing keys
+        cross_signing_keys = yield self.get_cross_signing_keys_from_cache(
+            device_keys_query, None
+        )
+
+        ret.update(cross_signing_keys)
+
+        return ret
 
     @trace
     @defer.inlineCallbacks
@@ -688,17 +711,21 @@ class E2eKeysHandler(object):
 
         try:
             # get our self-signing key to verify the signatures
-            _, self_signing_key_id, self_signing_verify_key = yield self._get_e2e_cross_signing_verify_key(
-                user_id, "self_signing"
-            )
+            (
+                _,
+                self_signing_key_id,
+                self_signing_verify_key,
+            ) = yield self._get_e2e_cross_signing_verify_key(user_id, "self_signing")
 
             # get our master key, since we may have received a signature of it.
             # We need to fetch it here so that we know what its key ID is, so
             # that we can check if a signature that was sent is a signature of
             # the master key or of a device
-            master_key, _, master_verify_key = yield self._get_e2e_cross_signing_verify_key(
-                user_id, "master"
-            )
+            (
+                master_key,
+                _,
+                master_verify_key,
+            ) = yield self._get_e2e_cross_signing_verify_key(user_id, "master")
 
             # fetch our stored devices.  This is used to 1. verify
             # signatures on the master key, and 2. to compare with what
@@ -838,9 +865,11 @@ class E2eKeysHandler(object):
 
         try:
             # get our user-signing key to verify the signatures
-            user_signing_key, user_signing_key_id, user_signing_verify_key = yield self._get_e2e_cross_signing_verify_key(
-                user_id, "user_signing"
-            )
+            (
+                user_signing_key,
+                user_signing_key_id,
+                user_signing_verify_key,
+            ) = yield self._get_e2e_cross_signing_verify_key(user_id, "user_signing")
         except SynapseError as e:
             failure = _exception_to_failure(e)
             for user, devicemap in signatures.items():
@@ -859,7 +888,11 @@ class E2eKeysHandler(object):
             try:
                 # get the target user's master key, to make sure it matches
                 # what was sent
-                master_key, master_key_id, _ = yield self._get_e2e_cross_signing_verify_key(
+                (
+                    master_key,
+                    master_key_id,
+                    _,
+                ) = yield self._get_e2e_cross_signing_verify_key(
                     target_user, "master", user_id
                 )
 
@@ -1047,3 +1080,100 @@ class SignatureListItem:
     target_user_id = attr.ib()
     target_device_id = attr.ib()
     signature = attr.ib()
+
+
+class SigningKeyEduUpdater(object):
+    """Handles incoming signing key updates from federation and updates the DB"""
+
+    def __init__(self, hs, e2e_keys_handler):
+        self.store = hs.get_datastore()
+        self.federation = hs.get_federation_client()
+        self.clock = hs.get_clock()
+        self.e2e_keys_handler = e2e_keys_handler
+
+        self._remote_edu_linearizer = Linearizer(name="remote_signing_key")
+
+        # user_id -> list of updates waiting to be handled.
+        self._pending_updates = {}
+
+        # Recently seen stream ids. We don't bother keeping these in the DB,
+        # but they're useful to have them about to reduce the number of spurious
+        # resyncs.
+        self._seen_updates = ExpiringCache(
+            cache_name="signing_key_update_edu",
+            clock=self.clock,
+            max_len=10000,
+            expiry_ms=30 * 60 * 1000,
+            iterable=True,
+        )
+
+    @defer.inlineCallbacks
+    def incoming_signing_key_update(self, origin, edu_content):
+        """Called on incoming signing key update from federation. Responsible for
+        parsing the EDU and adding to pending updates list.
+
+        Args:
+            origin (string): the server that sent the EDU
+            edu_content (dict): the contents of the EDU
+        """
+
+        user_id = edu_content.pop("user_id")
+        master_key = edu_content.pop("master_key", None)
+        self_signing_key = edu_content.pop("self_signing_key", None)
+
+        if get_domain_from_id(user_id) != origin:
+            logger.warning("Got signing key update edu for %r from %r", user_id, origin)
+            return
+
+        room_ids = yield self.store.get_rooms_for_user(user_id)
+        if not room_ids:
+            # We don't share any rooms with this user. Ignore update, as we
+            # probably won't get any further updates.
+            return
+
+        self._pending_updates.setdefault(user_id, []).append(
+            (master_key, self_signing_key)
+        )
+
+        yield self._handle_signing_key_updates(user_id)
+
+    @defer.inlineCallbacks
+    def _handle_signing_key_updates(self, user_id):
+        """Actually handle pending updates.
+
+        Args:
+            user_id (string): the user whose updates we are processing
+        """
+
+        device_handler = self.e2e_keys_handler.device_handler
+
+        with (yield self._remote_edu_linearizer.queue(user_id)):
+            pending_updates = self._pending_updates.pop(user_id, [])
+            if not pending_updates:
+                # This can happen since we batch updates
+                return
+
+            device_ids = []
+
+            logger.info("pending updates: %r", pending_updates)
+
+            for master_key, self_signing_key in pending_updates:
+                if master_key:
+                    yield self.store.set_e2e_cross_signing_key(
+                        user_id, "master", master_key
+                    )
+                    _, verify_key = get_verify_key_from_cross_signing_key(master_key)
+                    # verify_key is a VerifyKey from signedjson, which uses
+                    # .version to denote the portion of the key ID after the
+                    # algorithm and colon, which is the device ID
+                    device_ids.append(verify_key.version)
+                if self_signing_key:
+                    yield self.store.set_e2e_cross_signing_key(
+                        user_id, "self_signing", self_signing_key
+                    )
+                    _, verify_key = get_verify_key_from_cross_signing_key(
+                        self_signing_key
+                    )
+                    device_ids.append(verify_key.version)
+
+            yield device_handler.notify_device_update(user_id, device_ids)
diff --git a/synapse/handlers/events.py b/synapse/handlers/events.py
index 5e748687e3..45fe13c62f 100644
--- a/synapse/handlers/events.py
+++ b/synapse/handlers/events.py
@@ -147,6 +147,10 @@ class EventStreamHandler(BaseHandler):
 
 
 class EventHandler(BaseHandler):
+    def __init__(self, hs):
+        super(EventHandler, self).__init__(hs)
+        self.storage = hs.get_storage()
+
     @defer.inlineCallbacks
     def get_event(self, user, room_id, event_id):
         """Retrieve a single specified event.
@@ -172,7 +176,7 @@ class EventHandler(BaseHandler):
         is_peeking = user.to_string() not in users
 
         filtered = yield filter_events_for_client(
-            self.store, user.to_string(), [event], is_peeking=is_peeking
+            self.storage, user.to_string(), [event], is_peeking=is_peeking
         )
 
         if not filtered:
diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py
index 488058fe68..05dd8d2671 100644
--- a/synapse/handlers/federation.py
+++ b/synapse/handlers/federation.py
@@ -45,6 +45,7 @@ from synapse.api.errors import (
 from synapse.api.room_versions import KNOWN_ROOM_VERSIONS, RoomVersions
 from synapse.crypto.event_signing import compute_event_signature
 from synapse.event_auth import auth_types_for_event
+from synapse.events.snapshot import EventContext
 from synapse.events.validator import EventValidator
 from synapse.logging.context import (
     make_deferred_yieldable,
@@ -109,6 +110,8 @@ class FederationHandler(BaseHandler):
         self.hs = hs
 
         self.store = hs.get_datastore()
+        self.storage = hs.get_storage()
+        self.state_store = self.storage.state
         self.federation_client = hs.get_federation_client()
         self.state_handler = hs.get_state_handler()
         self.server_name = hs.hostname
@@ -180,7 +183,7 @@ class FederationHandler(BaseHandler):
         try:
             self._sanity_check_event(pdu)
         except SynapseError as err:
-            logger.warn(
+            logger.warning(
                 "[%s %s] Received event failed sanity checks", room_id, event_id
             )
             raise FederationError("ERROR", err.code, err.msg, affected=pdu.event_id)
@@ -301,7 +304,7 @@ class FederationHandler(BaseHandler):
                 # following.
 
                 if sent_to_us_directly:
-                    logger.warn(
+                    logger.warning(
                         "[%s %s] Rejecting: failed to fetch %d prev events: %s",
                         room_id,
                         event_id,
@@ -324,7 +327,7 @@ class FederationHandler(BaseHandler):
                 event_map = {event_id: pdu}
                 try:
                     # Get the state of the events we know about
-                    ours = yield self.store.get_state_groups_ids(room_id, seen)
+                    ours = yield self.state_store.get_state_groups_ids(room_id, seen)
 
                     # state_maps is a list of mappings from (type, state_key) to event_id
                     state_maps = list(
@@ -350,10 +353,11 @@ class FederationHandler(BaseHandler):
                             # note that if any of the missing prevs share missing state or
                             # auth events, the requests to fetch those events are deduped
                             # by the get_pdu_cache in federation_client.
-                            remote_state, got_auth_chain = (
-                                yield self.federation_client.get_state_for_room(
-                                    origin, room_id, p
-                                )
+                            (
+                                remote_state,
+                                got_auth_chain,
+                            ) = yield self.federation_client.get_state_for_room(
+                                origin, room_id, p
                             )
 
                             # we want the state *after* p; get_state_for_room returns the
@@ -405,7 +409,7 @@ class FederationHandler(BaseHandler):
                     state = [event_map[e] for e in six.itervalues(state_map)]
                     auth_chain = list(auth_chains)
                 except Exception:
-                    logger.warn(
+                    logger.warning(
                         "[%s %s] Error attempting to resolve state at missing "
                         "prev_events",
                         room_id,
@@ -518,7 +522,9 @@ class FederationHandler(BaseHandler):
             # We failed to get the missing events, but since we need to handle
             # the case of `get_missing_events` not returning the necessary
             # events anyway, it is safe to simply log the error and continue.
-            logger.warn("[%s %s]: Failed to get prev_events: %s", room_id, event_id, e)
+            logger.warning(
+                "[%s %s]: Failed to get prev_events: %s", room_id, event_id, e
+            )
             return
 
         logger.info(
@@ -545,7 +551,7 @@ class FederationHandler(BaseHandler):
                     yield self.on_receive_pdu(origin, ev, sent_to_us_directly=False)
                 except FederationError as e:
                     if e.code == 403:
-                        logger.warn(
+                        logger.warning(
                             "[%s %s] Received prev_event %s failed history check.",
                             room_id,
                             event_id,
@@ -888,7 +894,7 @@ class FederationHandler(BaseHandler):
         # We set `check_history_visibility_only` as we might otherwise get false
         # positives from users having been erased.
         filtered_extremities = yield filter_events_for_server(
-            self.store,
+            self.storage,
             self.server_name,
             list(extremities_events.values()),
             redact=False,
@@ -1059,7 +1065,7 @@ class FederationHandler(BaseHandler):
             SynapseError if the event does not pass muster
         """
         if len(ev.prev_event_ids()) > 20:
-            logger.warn(
+            logger.warning(
                 "Rejecting event %s which has %i prev_events",
                 ev.event_id,
                 len(ev.prev_event_ids()),
@@ -1067,7 +1073,7 @@ class FederationHandler(BaseHandler):
             raise SynapseError(http_client.BAD_REQUEST, "Too many prev_events")
 
         if len(ev.auth_event_ids()) > 10:
-            logger.warn(
+            logger.warning(
                 "Rejecting event %s which has %i auth_events",
                 ev.event_id,
                 len(ev.auth_event_ids()),
@@ -1101,7 +1107,7 @@ class FederationHandler(BaseHandler):
     @defer.inlineCallbacks
     def do_invite_join(self, target_hosts, room_id, joinee, content):
         """ Attempts to join the `joinee` to the room `room_id` via the
-        server `target_host`.
+        servers contained in `target_hosts`.
 
         This first triggers a /make_join/ request that returns a partial
         event that we can fill out and sign. This is then sent to the
@@ -1110,6 +1116,15 @@ class FederationHandler(BaseHandler):
 
         We suspend processing of any received events from this room until we
         have finished processing the join.
+
+        Args:
+            target_hosts (Iterable[str]): List of servers to attempt to join the room with.
+
+            room_id (str): The ID of the room to join.
+
+            joinee (str): The User ID of the joining user.
+
+            content (dict): The event content to use for the join event.
         """
         logger.debug("Joining %s to %s", joinee, room_id)
 
@@ -1169,6 +1184,22 @@ class FederationHandler(BaseHandler):
 
             yield self._persist_auth_tree(origin, auth_chain, state, event)
 
+            # Check whether this room is the result of an upgrade of a room we already know
+            # about. If so, migrate over user information
+            predecessor = yield self.store.get_room_predecessor(room_id)
+            if not predecessor:
+                return
+            old_room_id = predecessor["room_id"]
+            logger.debug(
+                "Found predecessor for %s during remote join: %s", room_id, old_room_id
+            )
+
+            # We retrieve the room member handler here as to not cause a cyclic dependency
+            member_handler = self.hs.get_room_member_handler()
+            yield member_handler.transfer_room_state_on_room_upgrade(
+                old_room_id, room_id
+            )
+
             logger.debug("Finished joining %s to %s", joinee, room_id)
         finally:
             room_queue = self.room_queues[room_id]
@@ -1203,7 +1234,7 @@ class FederationHandler(BaseHandler):
                 with nested_logging_context(p.event_id):
                     yield self.on_receive_pdu(origin, p, sent_to_us_directly=True)
             except Exception as e:
-                logger.warn(
+                logger.warning(
                     "Error handling queued PDU %s from %s: %s", p.event_id, origin, e
                 )
 
@@ -1250,7 +1281,7 @@ class FederationHandler(BaseHandler):
                 builder=builder
             )
         except AuthError as e:
-            logger.warn("Failed to create join %r because %s", event, e)
+            logger.warning("Failed to create join to %s because %s", room_id, e)
             raise e
 
         event_allowed = yield self.third_party_event_rules.check_event_allowed(
@@ -1494,7 +1525,7 @@ class FederationHandler(BaseHandler):
                 room_version, event, context, do_sig_check=False
             )
         except AuthError as e:
-            logger.warn("Failed to create new leave %r because %s", event, e)
+            logger.warning("Failed to create new leave %r because %s", event, e)
             raise e
 
         return event
@@ -1549,7 +1580,7 @@ class FederationHandler(BaseHandler):
             event_id, allow_none=False, check_room_id=room_id
         )
 
-        state_groups = yield self.store.get_state_groups(room_id, [event_id])
+        state_groups = yield self.state_store.get_state_groups(room_id, [event_id])
 
         if state_groups:
             _, state = list(iteritems(state_groups)).pop()
@@ -1578,7 +1609,7 @@ class FederationHandler(BaseHandler):
             event_id, allow_none=False, check_room_id=room_id
         )
 
-        state_groups = yield self.store.get_state_groups_ids(room_id, [event_id])
+        state_groups = yield self.state_store.get_state_groups_ids(room_id, [event_id])
 
         if state_groups:
             _, state = list(state_groups.items()).pop()
@@ -1606,7 +1637,7 @@ class FederationHandler(BaseHandler):
 
         events = yield self.store.get_backfill_events(room_id, pdu_list, limit)
 
-        events = yield filter_events_for_server(self.store, origin, events)
+        events = yield filter_events_for_server(self.storage, origin, events)
 
         return events
 
@@ -1636,7 +1667,7 @@ class FederationHandler(BaseHandler):
             if not in_room:
                 raise AuthError(403, "Host not in room.")
 
-            events = yield filter_events_for_server(self.store, origin, [event])
+            events = yield filter_events_for_server(self.storage, origin, [event])
             event = events[0]
             return event
         else:
@@ -1657,7 +1688,11 @@ class FederationHandler(BaseHandler):
         # hack around with a try/finally instead.
         success = False
         try:
-            if not event.internal_metadata.is_outlier() and not backfilled:
+            if (
+                not event.internal_metadata.is_outlier()
+                and not backfilled
+                and not context.rejected
+            ):
                 yield self.action_generator.handle_push_actions_for_event(
                     event, context
                 )
@@ -1788,7 +1823,7 @@ class FederationHandler(BaseHandler):
                 # cause SynapseErrors in auth.check. We don't want to give up
                 # the attempt to federate altogether in such cases.
 
-                logger.warn("Rejecting %s because %s", e.event_id, err.msg)
+                logger.warning("Rejecting %s because %s", e.event_id, err.msg)
 
                 if e == event:
                     raise
@@ -1841,12 +1876,7 @@ class FederationHandler(BaseHandler):
                 if c and c.type == EventTypes.Create:
                     auth_events[(c.type, c.state_key)] = c
 
-        try:
-            yield self.do_auth(origin, event, context, auth_events=auth_events)
-        except AuthError as e:
-            logger.warn("[%s %s] Rejecting: %s", event.room_id, event.event_id, e.msg)
-
-            context.rejected = RejectedReason.AUTH_ERROR
+        context = yield self.do_auth(origin, event, context, auth_events=auth_events)
 
         if not context.rejected:
             yield self._check_for_soft_fail(event, state, backfilled)
@@ -1902,7 +1932,7 @@ class FederationHandler(BaseHandler):
                 # given state at the event. This should correctly handle cases
                 # like bans, especially with state res v2.
 
-                state_sets = yield self.store.get_state_groups(
+                state_sets = yield self.state_store.get_state_groups(
                     event.room_id, extrem_ids
                 )
                 state_sets = list(state_sets.values())
@@ -1938,7 +1968,7 @@ class FederationHandler(BaseHandler):
             try:
                 event_auth.check(room_version, event, auth_events=current_auth_events)
             except AuthError as e:
-                logger.warn("Soft-failing %r because %s", event, e)
+                logger.warning("Soft-failing %r because %s", event, e)
                 event.internal_metadata.soft_failed = True
 
     @defer.inlineCallbacks
@@ -1993,7 +2023,7 @@ class FederationHandler(BaseHandler):
         )
 
         missing_events = yield filter_events_for_server(
-            self.store, origin, missing_events
+            self.storage, origin, missing_events
         )
 
         return missing_events
@@ -2015,12 +2045,12 @@ class FederationHandler(BaseHandler):
 
                 Also NB that this function adds entries to it.
         Returns:
-            defer.Deferred[None]
+            defer.Deferred[EventContext]: updated context object
         """
         room_version = yield self.store.get_room_version(event.room_id)
 
         try:
-            yield self._update_auth_events_and_context_for_auth(
+            context = yield self._update_auth_events_and_context_for_auth(
                 origin, event, context, auth_events
             )
         except Exception:
@@ -2037,8 +2067,10 @@ class FederationHandler(BaseHandler):
         try:
             event_auth.check(room_version, event, auth_events=auth_events)
         except AuthError as e:
-            logger.warn("Failed auth resolution for %r because %s", event, e)
-            raise e
+            logger.warning("Failed auth resolution for %r because %s", event, e)
+            context.rejected = RejectedReason.AUTH_ERROR
+
+        return context
 
     @defer.inlineCallbacks
     def _update_auth_events_and_context_for_auth(
@@ -2062,7 +2094,7 @@ class FederationHandler(BaseHandler):
             auth_events (dict[(str, str)->synapse.events.EventBase]):
 
         Returns:
-            defer.Deferred[None]
+            defer.Deferred[EventContext]: updated context
         """
         event_auth_events = set(event.auth_event_ids())
 
@@ -2101,7 +2133,7 @@ class FederationHandler(BaseHandler):
                     # The other side isn't around or doesn't implement the
                     # endpoint, so lets just bail out.
                     logger.info("Failed to get event auth from remote: %s", e)
-                    return
+                    return context
 
                 seen_remotes = yield self.store.have_seen_events(
                     [e.event_id for e in remote_auth_chain]
@@ -2142,7 +2174,7 @@ class FederationHandler(BaseHandler):
 
         if event.internal_metadata.is_outlier():
             logger.info("Skipping auth_event fetch for outlier")
-            return
+            return context
 
         # FIXME: Assumes we have and stored all the state for all the
         # prev_events
@@ -2151,7 +2183,7 @@ class FederationHandler(BaseHandler):
         )
 
         if not different_auth:
-            return
+            return context
 
         logger.info(
             "auth_events refers to events which are not in our calculated auth "
@@ -2198,10 +2230,12 @@ class FederationHandler(BaseHandler):
 
             auth_events.update(new_state)
 
-            yield self._update_context_for_auth_events(
+            context = yield self._update_context_for_auth_events(
                 event, context, auth_events, event_key
             )
 
+        return context
+
     @defer.inlineCallbacks
     def _update_context_for_auth_events(self, event, context, auth_events, event_key):
         """Update the state_ids in an event context after auth event resolution,
@@ -2210,14 +2244,16 @@ class FederationHandler(BaseHandler):
         Args:
             event (Event): The event we're handling the context for
 
-            context (synapse.events.snapshot.EventContext): event context
-                to be updated
+            context (synapse.events.snapshot.EventContext): initial event context
 
             auth_events (dict[(str, str)->str]): Events to update in the event
                 context.
 
             event_key ((str, str)): (type, state_key) for the current event.
                 this will not be included in the current_state in the context.
+
+        Returns:
+            Deferred[EventContext]: new event context
         """
         state_updates = {
             k: a.event_id for k, a in iteritems(auth_events) if k != event_key
@@ -2234,7 +2270,7 @@ class FederationHandler(BaseHandler):
 
         # create a new state group as a delta from the existing one.
         prev_group = context.state_group
-        state_group = yield self.store.store_state_group(
+        state_group = yield self.state_store.store_state_group(
             event.event_id,
             event.room_id,
             prev_group=prev_group,
@@ -2242,8 +2278,9 @@ class FederationHandler(BaseHandler):
             current_state_ids=current_state_ids,
         )
 
-        yield context.update_state(
+        return EventContext.with_state(
             state_group=state_group,
+            state_group_before_event=context.state_group_before_event,
             current_state_ids=current_state_ids,
             prev_state_ids=prev_state_ids,
             prev_group=prev_group,
@@ -2431,10 +2468,12 @@ class FederationHandler(BaseHandler):
             try:
                 yield self.auth.check_from_context(room_version, event, context)
             except AuthError as e:
-                logger.warn("Denying new third party invite %r because %s", event, e)
+                logger.warning("Denying new third party invite %r because %s", event, e)
                 raise e
 
             yield self._check_signature(event, context)
+
+            # We retrieve the room member handler here as to not cause a cyclic dependency
             member_handler = self.hs.get_room_member_handler()
             yield member_handler.send_membership_event(None, event, context)
         else:
@@ -2487,7 +2526,7 @@ class FederationHandler(BaseHandler):
         try:
             yield self.auth.check_from_context(room_version, event, context)
         except AuthError as e:
-            logger.warn("Denying third party invite %r because %s", event, e)
+            logger.warning("Denying third party invite %r because %s", event, e)
             raise e
         yield self._check_signature(event, context)
 
@@ -2495,6 +2534,7 @@ class FederationHandler(BaseHandler):
         # though the sender isn't a local user.
         event.internal_metadata.send_on_behalf_of = get_domain_from_id(event.sender)
 
+        # We retrieve the room member handler here as to not cause a cyclic dependency
         member_handler = self.hs.get_room_member_handler()
         yield member_handler.send_membership_event(None, event, context)
 
@@ -2664,7 +2704,7 @@ class FederationHandler(BaseHandler):
                 backfilled=backfilled,
             )
         else:
-            max_stream_id = yield self.store.persist_events(
+            max_stream_id = yield self.storage.persistence.persist_events(
                 event_and_contexts, backfilled=backfilled
             )
 
diff --git a/synapse/handlers/groups_local.py b/synapse/handlers/groups_local.py
index 46eb9ee88b..92fecbfc44 100644
--- a/synapse/handlers/groups_local.py
+++ b/synapse/handlers/groups_local.py
@@ -392,7 +392,7 @@ class GroupsLocalHandler(object):
         try:
             user_profile = yield self.profile_handler.get_profile(user_id)
         except Exception as e:
-            logger.warn("No profile for user %s: %s", user_id, e)
+            logger.warning("No profile for user %s: %s", user_id, e)
             user_profile = {}
 
         return {"state": "invite", "user_profile": user_profile}
diff --git a/synapse/handlers/identity.py b/synapse/handlers/identity.py
index ba99ddf76d..000fbf090f 100644
--- a/synapse/handlers/identity.py
+++ b/synapse/handlers/identity.py
@@ -272,7 +272,7 @@ class IdentityHandler(BaseHandler):
             changed = False
             if e.code in (400, 404, 501):
                 # The remote server probably doesn't support unbinding (yet)
-                logger.warn("Received %d response while unbinding threepid", e.code)
+                logger.warning("Received %d response while unbinding threepid", e.code)
             else:
                 logger.error("Failed to unbind threepid on identity server: %s", e)
                 raise SynapseError(500, "Failed to contact identity server")
@@ -403,7 +403,7 @@ class IdentityHandler(BaseHandler):
 
         if self.hs.config.using_identity_server_from_trusted_list:
             # Warn that a deprecated config option is in use
-            logger.warn(
+            logger.warning(
                 'The config option "trust_identity_server_for_password_resets" '
                 'has been replaced by "account_threepid_delegate". '
                 "Please consult the sample config at docs/sample_config.yaml for "
@@ -457,7 +457,7 @@ class IdentityHandler(BaseHandler):
 
         if self.hs.config.using_identity_server_from_trusted_list:
             # Warn that a deprecated config option is in use
-            logger.warn(
+            logger.warning(
                 'The config option "trust_identity_server_for_password_resets" '
                 'has been replaced by "account_threepid_delegate". '
                 "Please consult the sample config at docs/sample_config.yaml for "
diff --git a/synapse/handlers/initial_sync.py b/synapse/handlers/initial_sync.py
index f991efeee3..81dce96f4b 100644
--- a/synapse/handlers/initial_sync.py
+++ b/synapse/handlers/initial_sync.py
@@ -43,6 +43,8 @@ class InitialSyncHandler(BaseHandler):
         self.validator = EventValidator()
         self.snapshot_cache = SnapshotCache()
         self._event_serializer = hs.get_event_client_serializer()
+        self.storage = hs.get_storage()
+        self.state_store = self.storage.state
 
     def snapshot_all_rooms(
         self,
@@ -126,8 +128,8 @@ class InitialSyncHandler(BaseHandler):
 
         tags_by_room = yield self.store.get_tags_for_user(user_id)
 
-        account_data, account_data_by_room = (
-            yield self.store.get_account_data_for_user(user_id)
+        account_data, account_data_by_room = yield self.store.get_account_data_for_user(
+            user_id
         )
 
         public_room_ids = yield self.store.get_public_room_ids()
@@ -169,7 +171,7 @@ class InitialSyncHandler(BaseHandler):
                 elif event.membership == Membership.LEAVE:
                     room_end_token = "s%d" % (event.stream_ordering,)
                     deferred_room_state = run_in_background(
-                        self.store.get_state_for_events, [event.event_id]
+                        self.state_store.get_state_for_events, [event.event_id]
                     )
                     deferred_room_state.addCallback(
                         lambda states: states[event.event_id]
@@ -189,7 +191,9 @@ class InitialSyncHandler(BaseHandler):
                     )
                 ).addErrback(unwrapFirstError)
 
-                messages = yield filter_events_for_client(self.store, user_id, messages)
+                messages = yield filter_events_for_client(
+                    self.storage, user_id, messages
+                )
 
                 start_token = now_token.copy_and_replace("room_key", token)
                 end_token = now_token.copy_and_replace("room_key", room_end_token)
@@ -307,7 +311,7 @@ class InitialSyncHandler(BaseHandler):
     def _room_initial_sync_parted(
         self, user_id, room_id, pagin_config, membership, member_event_id, is_peeking
     ):
-        room_state = yield self.store.get_state_for_events([member_event_id])
+        room_state = yield self.state_store.get_state_for_events([member_event_id])
 
         room_state = room_state[member_event_id]
 
@@ -322,7 +326,7 @@ class InitialSyncHandler(BaseHandler):
         )
 
         messages = yield filter_events_for_client(
-            self.store, user_id, messages, is_peeking=is_peeking
+            self.storage, user_id, messages, is_peeking=is_peeking
         )
 
         start_token = StreamToken.START.copy_and_replace("room_key", token)
@@ -414,7 +418,7 @@ class InitialSyncHandler(BaseHandler):
         )
 
         messages = yield filter_events_for_client(
-            self.store, user_id, messages, is_peeking=is_peeking
+            self.storage, user_id, messages, is_peeking=is_peeking
         )
 
         start_token = now_token.copy_and_replace("room_key", token)
diff --git a/synapse/handlers/message.py b/synapse/handlers/message.py
index 0f8cce8ffe..d682dc2b7a 100644
--- a/synapse/handlers/message.py
+++ b/synapse/handlers/message.py
@@ -59,6 +59,8 @@ class MessageHandler(object):
         self.clock = hs.get_clock()
         self.state = hs.get_state_handler()
         self.store = hs.get_datastore()
+        self.storage = hs.get_storage()
+        self.state_store = self.storage.state
         self._event_serializer = hs.get_event_client_serializer()
 
     @defer.inlineCallbacks
@@ -74,15 +76,16 @@ class MessageHandler(object):
         Raises:
             SynapseError if something went wrong.
         """
-        membership, membership_event_id = yield self.auth.check_in_room_or_world_readable(
-            room_id, user_id
-        )
+        (
+            membership,
+            membership_event_id,
+        ) = yield self.auth.check_in_room_or_world_readable(room_id, user_id)
 
         if membership == Membership.JOIN:
             data = yield self.state.get_current_state(room_id, event_type, state_key)
         elif membership == Membership.LEAVE:
             key = (event_type, state_key)
-            room_state = yield self.store.get_state_for_events(
+            room_state = yield self.state_store.get_state_for_events(
                 [membership_event_id], StateFilter.from_types([key])
             )
             data = room_state[membership_event_id].get(key)
@@ -135,12 +138,12 @@ class MessageHandler(object):
                 raise NotFoundError("Can't find event for token %s" % (at_token,))
 
             visible_events = yield filter_events_for_client(
-                self.store, user_id, last_events
+                self.storage, user_id, last_events
             )
 
             event = last_events[0]
             if visible_events:
-                room_state = yield self.store.get_state_for_events(
+                room_state = yield self.state_store.get_state_for_events(
                     [event.event_id], state_filter=state_filter
                 )
                 room_state = room_state[event.event_id]
@@ -151,9 +154,10 @@ class MessageHandler(object):
                     % (user_id, room_id, at_token),
                 )
         else:
-            membership, membership_event_id = (
-                yield self.auth.check_in_room_or_world_readable(room_id, user_id)
-            )
+            (
+                membership,
+                membership_event_id,
+            ) = yield self.auth.check_in_room_or_world_readable(room_id, user_id)
 
             if membership == Membership.JOIN:
                 state_ids = yield self.store.get_filtered_current_state_ids(
@@ -161,7 +165,7 @@ class MessageHandler(object):
                 )
                 room_state = yield self.store.get_events(state_ids.values())
             elif membership == Membership.LEAVE:
-                room_state = yield self.store.get_state_for_events(
+                room_state = yield self.state_store.get_state_for_events(
                     [membership_event_id], state_filter=state_filter
                 )
                 room_state = room_state[membership_event_id]
@@ -234,6 +238,7 @@ class EventCreationHandler(object):
         self.hs = hs
         self.auth = hs.get_auth()
         self.store = hs.get_datastore()
+        self.storage = hs.get_storage()
         self.state = hs.get_state_handler()
         self.clock = hs.get_clock()
         self.validator = EventValidator()
@@ -687,7 +692,7 @@ class EventCreationHandler(object):
         try:
             yield self.auth.check_from_context(room_version, event, context)
         except AuthError as err:
-            logger.warn("Denying new event %r because %s", event, err)
+            logger.warning("Denying new event %r because %s", event, err)
             raise err
 
         # Ensure that we can round trip before trying to persist in db
@@ -868,7 +873,7 @@ class EventCreationHandler(object):
             if prev_state_ids:
                 raise AuthError(403, "Changing the room create event is forbidden")
 
-        (event_stream_id, max_stream_id) = yield self.store.persist_event(
+        event_stream_id, max_stream_id = yield self.storage.persistence.persist_event(
             event, context=context
         )
 
diff --git a/synapse/handlers/pagination.py b/synapse/handlers/pagination.py
index 5744f4579d..97f15a1c32 100644
--- a/synapse/handlers/pagination.py
+++ b/synapse/handlers/pagination.py
@@ -69,6 +69,8 @@ class PaginationHandler(object):
         self.hs = hs
         self.auth = hs.get_auth()
         self.store = hs.get_datastore()
+        self.storage = hs.get_storage()
+        self.state_store = self.storage.state
         self.clock = hs.get_clock()
         self._server_name = hs.hostname
 
@@ -210,9 +212,10 @@ class PaginationHandler(object):
         source_config = pagin_config.get_source_config("room")
 
         with (yield self.pagination_lock.read(room_id)):
-            membership, member_event_id = yield self.auth.check_in_room_or_world_readable(
-                room_id, user_id
-            )
+            (
+                membership,
+                member_event_id,
+            ) = yield self.auth.check_in_room_or_world_readable(room_id, user_id)
 
             if source_config.direction == "b":
                 # if we're going backwards, we might need to backfill. This
@@ -255,7 +258,7 @@ class PaginationHandler(object):
                 events = event_filter.filter(events)
 
             events = yield filter_events_for_client(
-                self.store, user_id, events, is_peeking=(member_event_id is None)
+                self.storage, user_id, events, is_peeking=(member_event_id is None)
             )
 
         if not events:
@@ -274,7 +277,7 @@ class PaginationHandler(object):
                 (EventTypes.Member, event.sender) for event in events
             )
 
-            state_ids = yield self.store.get_state_ids_for_event(
+            state_ids = yield self.state_store.get_state_ids_for_event(
                 events[0].event_id, state_filter=state_filter
             )
 
@@ -295,10 +298,8 @@ class PaginationHandler(object):
         }
 
         if state:
-            chunk["state"] = (
-                yield self._event_serializer.serialize_events(
-                    state, time_now, as_client_event=as_client_event
-                )
+            chunk["state"] = yield self._event_serializer.serialize_events(
+                state, time_now, as_client_event=as_client_event
             )
 
         return chunk
diff --git a/synapse/handlers/profile.py b/synapse/handlers/profile.py
index 8690f69d45..22e0a04da4 100644
--- a/synapse/handlers/profile.py
+++ b/synapse/handlers/profile.py
@@ -275,7 +275,7 @@ class BaseProfileHandler(BaseHandler):
                     ratelimit=False,  # Try to hide that these events aren't atomic.
                 )
             except Exception as e:
-                logger.warn(
+                logger.warning(
                     "Failed to update join event for room %s - %s", room_id, str(e)
                 )
 
diff --git a/synapse/handlers/read_marker.py b/synapse/handlers/read_marker.py
index 3e4d8c93a4..e3b528d271 100644
--- a/synapse/handlers/read_marker.py
+++ b/synapse/handlers/read_marker.py
@@ -15,8 +15,6 @@
 
 import logging
 
-from twisted.internet import defer
-
 from synapse.util.async_helpers import Linearizer
 
 from ._base import BaseHandler
@@ -32,8 +30,7 @@ class ReadMarkerHandler(BaseHandler):
         self.read_marker_linearizer = Linearizer(name="read_marker")
         self.notifier = hs.get_notifier()
 
-    @defer.inlineCallbacks
-    def received_client_read_marker(self, room_id, user_id, event_id):
+    async def received_client_read_marker(self, room_id, user_id, event_id):
         """Updates the read marker for a given user in a given room if the event ID given
         is ahead in the stream relative to the current read marker.
 
@@ -41,8 +38,8 @@ class ReadMarkerHandler(BaseHandler):
         the read marker has changed.
         """
 
-        with (yield self.read_marker_linearizer.queue((room_id, user_id))):
-            existing_read_marker = yield self.store.get_account_data_for_room_and_type(
+        with await self.read_marker_linearizer.queue((room_id, user_id)):
+            existing_read_marker = await self.store.get_account_data_for_room_and_type(
                 user_id, room_id, "m.fully_read"
             )
 
@@ -50,13 +47,13 @@ class ReadMarkerHandler(BaseHandler):
 
             if existing_read_marker:
                 # Only update if the new marker is ahead in the stream
-                should_update = yield self.store.is_event_after(
+                should_update = await self.store.is_event_after(
                     event_id, existing_read_marker["event_id"]
                 )
 
             if should_update:
                 content = {"event_id": event_id}
-                max_id = yield self.store.add_account_data_to_room(
+                max_id = await self.store.add_account_data_to_room(
                     user_id, room_id, "m.fully_read", content
                 )
                 self.notifier.on_new_event("account_data_key", max_id, users=[user_id])
diff --git a/synapse/handlers/receipts.py b/synapse/handlers/receipts.py
index 6854c751a6..9283c039e3 100644
--- a/synapse/handlers/receipts.py
+++ b/synapse/handlers/receipts.py
@@ -18,6 +18,7 @@ from twisted.internet import defer
 
 from synapse.handlers._base import BaseHandler
 from synapse.types import ReadReceipt, get_domain_from_id
+from synapse.util.async_helpers import maybe_awaitable
 
 logger = logging.getLogger(__name__)
 
@@ -36,8 +37,7 @@ class ReceiptsHandler(BaseHandler):
         self.clock = self.hs.get_clock()
         self.state = hs.get_state_handler()
 
-    @defer.inlineCallbacks
-    def _received_remote_receipt(self, origin, content):
+    async def _received_remote_receipt(self, origin, content):
         """Called when we receive an EDU of type m.receipt from a remote HS.
         """
         receipts = []
@@ -62,17 +62,16 @@ class ReceiptsHandler(BaseHandler):
                         )
                     )
 
-        yield self._handle_new_receipts(receipts)
+        await self._handle_new_receipts(receipts)
 
-    @defer.inlineCallbacks
-    def _handle_new_receipts(self, receipts):
+    async def _handle_new_receipts(self, receipts):
         """Takes a list of receipts, stores them and informs the notifier.
         """
         min_batch_id = None
         max_batch_id = None
 
         for receipt in receipts:
-            res = yield self.store.insert_receipt(
+            res = await self.store.insert_receipt(
                 receipt.room_id,
                 receipt.receipt_type,
                 receipt.user_id,
@@ -99,14 +98,15 @@ class ReceiptsHandler(BaseHandler):
 
         self.notifier.on_new_event("receipt_key", max_batch_id, rooms=affected_room_ids)
         # Note that the min here shouldn't be relied upon to be accurate.
-        yield self.hs.get_pusherpool().on_new_receipts(
-            min_batch_id, max_batch_id, affected_room_ids
+        await maybe_awaitable(
+            self.hs.get_pusherpool().on_new_receipts(
+                min_batch_id, max_batch_id, affected_room_ids
+            )
         )
 
         return True
 
-    @defer.inlineCallbacks
-    def received_client_receipt(self, room_id, receipt_type, user_id, event_id):
+    async def received_client_receipt(self, room_id, receipt_type, user_id, event_id):
         """Called when a client tells us a local user has read up to the given
         event_id in the room.
         """
@@ -118,24 +118,11 @@ class ReceiptsHandler(BaseHandler):
             data={"ts": int(self.clock.time_msec())},
         )
 
-        is_new = yield self._handle_new_receipts([receipt])
+        is_new = await self._handle_new_receipts([receipt])
         if not is_new:
             return
 
-        yield self.federation.send_read_receipt(receipt)
-
-    @defer.inlineCallbacks
-    def get_receipts_for_room(self, room_id, to_key):
-        """Gets all receipts for a room, upto the given key.
-        """
-        result = yield self.store.get_linearized_receipts_for_room(
-            room_id, to_key=to_key
-        )
-
-        if not result:
-            return []
-
-        return result
+        await self.federation.send_read_receipt(receipt)
 
 
 class ReceiptEventSource(object):
diff --git a/synapse/handlers/register.py b/synapse/handlers/register.py
index 53410f120b..cff6b0d375 100644
--- a/synapse/handlers/register.py
+++ b/synapse/handlers/register.py
@@ -396,8 +396,8 @@ class RegistrationHandler(BaseHandler):
             room_id = room_identifier
         elif RoomAlias.is_valid(room_identifier):
             room_alias = RoomAlias.from_string(room_identifier)
-            room_id, remote_room_hosts = (
-                yield room_member_handler.lookup_room_alias(room_alias)
+            room_id, remote_room_hosts = yield room_member_handler.lookup_room_alias(
+                room_alias
             )
             room_id = room_id.to_string()
         else:
diff --git a/synapse/handlers/room.py b/synapse/handlers/room.py
index 2816bd8f87..e92b2eafd5 100644
--- a/synapse/handlers/room.py
+++ b/synapse/handlers/room.py
@@ -129,6 +129,7 @@ class RoomCreationHandler(BaseHandler):
             old_room_id,
             new_version,  # args for _upgrade_room
         )
+
         return ret
 
     @defer.inlineCallbacks
@@ -147,21 +148,22 @@ class RoomCreationHandler(BaseHandler):
 
         # we create and auth the tombstone event before properly creating the new
         # room, to check our user has perms in the old room.
-        tombstone_event, tombstone_context = (
-            yield self.event_creation_handler.create_event(
-                requester,
-                {
-                    "type": EventTypes.Tombstone,
-                    "state_key": "",
-                    "room_id": old_room_id,
-                    "sender": user_id,
-                    "content": {
-                        "body": "This room has been replaced",
-                        "replacement_room": new_room_id,
-                    },
+        (
+            tombstone_event,
+            tombstone_context,
+        ) = yield self.event_creation_handler.create_event(
+            requester,
+            {
+                "type": EventTypes.Tombstone,
+                "state_key": "",
+                "room_id": old_room_id,
+                "sender": user_id,
+                "content": {
+                    "body": "This room has been replaced",
+                    "replacement_room": new_room_id,
                 },
-                token_id=requester.access_token_id,
-            )
+            },
+            token_id=requester.access_token_id,
         )
         old_room_version = yield self.store.get_room_version(old_room_id)
         yield self.auth.check_from_context(
@@ -188,7 +190,12 @@ class RoomCreationHandler(BaseHandler):
             requester, old_room_id, new_room_id, old_room_state
         )
 
-        # and finally, shut down the PLs in the old room, and update them in the new
+        # Copy over user push rules, tags and migrate room directory state
+        yield self.room_member_handler.transfer_room_state_on_room_upgrade(
+            old_room_id, new_room_id
+        )
+
+        # finally, shut down the PLs in the old room, and update them in the new
         # room.
         yield self._update_upgraded_room_pls(
             requester, old_room_id, new_room_id, old_room_state
@@ -822,6 +829,8 @@ class RoomContextHandler(object):
     def __init__(self, hs):
         self.hs = hs
         self.store = hs.get_datastore()
+        self.storage = hs.get_storage()
+        self.state_store = self.storage.state
 
     @defer.inlineCallbacks
     def get_event_context(self, user, room_id, event_id, limit, event_filter):
@@ -848,7 +857,7 @@ class RoomContextHandler(object):
 
         def filter_evts(events):
             return filter_events_for_client(
-                self.store, user.to_string(), events, is_peeking=is_peeking
+                self.storage, user.to_string(), events, is_peeking=is_peeking
             )
 
         event = yield self.store.get_event(
@@ -890,7 +899,7 @@ class RoomContextHandler(object):
         # first? Shouldn't we be consistent with /sync?
         # https://github.com/matrix-org/matrix-doc/issues/687
 
-        state = yield self.store.get_state_for_events(
+        state = yield self.state_store.get_state_for_events(
             [last_event_id], state_filter=state_filter
         )
         results["state"] = list(state[last_event_id].values())
@@ -922,7 +931,7 @@ class RoomEventSource(object):
 
         from_token = RoomStreamToken.parse(from_key)
         if from_token.topological:
-            logger.warn("Stream has topological part!!!! %r", from_key)
+            logger.warning("Stream has topological part!!!! %r", from_key)
             from_key = "s%s" % (from_token.stream,)
 
         app_service = self.store.get_app_service_by_user_id(user.to_string())
diff --git a/synapse/handlers/room_member.py b/synapse/handlers/room_member.py
index 380e2fad5e..06d09c2947 100644
--- a/synapse/handlers/room_member.py
+++ b/synapse/handlers/room_member.py
@@ -203,10 +203,6 @@ class RoomMemberHandler(object):
                 prev_member_event = yield self.store.get_event(prev_member_event_id)
                 newly_joined = prev_member_event.membership != Membership.JOIN
             if newly_joined:
-                # Copy over user state if we're joining an upgraded room
-                yield self.copy_user_state_if_room_upgrade(
-                    room_id, requester.user.to_string()
-                )
                 yield self._user_joined_room(target, room_id)
         elif event.membership == Membership.LEAVE:
             if prev_member_event_id:
@@ -455,11 +451,6 @@ class RoomMemberHandler(object):
                     requester, remote_room_hosts, room_id, target, content
                 )
 
-                # Copy over user state if this is a join on an remote upgraded room
-                yield self.copy_user_state_if_room_upgrade(
-                    room_id, requester.user.to_string()
-                )
-
                 return remote_join_response
 
         elif effective_membership_state == Membership.LEAVE:
@@ -498,36 +489,72 @@ class RoomMemberHandler(object):
         return res
 
     @defer.inlineCallbacks
-    def copy_user_state_if_room_upgrade(self, new_room_id, user_id):
-        """Copy user-specific information when they join a new room if that new room is the
+    def transfer_room_state_on_room_upgrade(self, old_room_id, room_id):
+        """Upon our server becoming aware of an upgraded room, either by upgrading a room
+        ourselves or joining one, we can transfer over information from the previous room.
+
+        Copies user state (tags/push rules) for every local user that was in the old room, as
+        well as migrating the room directory state.
+
+        Args:
+            old_room_id (str): The ID of the old room
+
+            room_id (str): The ID of the new room
+
+        Returns:
+            Deferred
+        """
+        # Find all local users that were in the old room and copy over each user's state
+        users = yield self.store.get_users_in_room(old_room_id)
+        yield self.copy_user_state_on_room_upgrade(old_room_id, room_id, users)
+
+        # Add new room to the room directory if the old room was there
+        # Remove old room from the room directory
+        old_room = yield self.store.get_room(old_room_id)
+        if old_room and old_room["is_public"]:
+            yield self.store.set_room_is_public(old_room_id, False)
+            yield self.store.set_room_is_public(room_id, True)
+
+    @defer.inlineCallbacks
+    def copy_user_state_on_room_upgrade(self, old_room_id, new_room_id, user_ids):
+        """Copy user-specific information when they join a new room when that new room is the
         result of a room upgrade
 
         Args:
-            new_room_id (str): The ID of the room the user is joining
-            user_id (str): The ID of the user
+            old_room_id (str): The ID of upgraded room
+            new_room_id (str): The ID of the new room
+            user_ids (Iterable[str]): User IDs to copy state for
 
         Returns:
             Deferred
         """
-        # Check if the new room is an upgraded room
-        predecessor = yield self.store.get_room_predecessor(new_room_id)
-        if not predecessor:
-            return
 
         logger.debug(
-            "Found predecessor for %s: %s. Copying over room tags and push " "rules",
+            "Copying over room tags and push rules from %s to %s for users %s",
+            old_room_id,
             new_room_id,
-            predecessor,
+            user_ids,
         )
 
-        # It is an upgraded room. Copy over old tags
-        yield self.copy_room_tags_and_direct_to_room(
-            predecessor["room_id"], new_room_id, user_id
-        )
-        # Copy over push rules
-        yield self.store.copy_push_rules_from_room_to_room_for_user(
-            predecessor["room_id"], new_room_id, user_id
-        )
+        for user_id in user_ids:
+            try:
+                # It is an upgraded room. Copy over old tags
+                yield self.copy_room_tags_and_direct_to_room(
+                    old_room_id, new_room_id, user_id
+                )
+                # Copy over push rules
+                yield self.store.copy_push_rules_from_room_to_room_for_user(
+                    old_room_id, new_room_id, user_id
+                )
+            except Exception:
+                logger.exception(
+                    "Error copying tags and/or push rules from rooms %s to %s for user %s. "
+                    "Skipping...",
+                    old_room_id,
+                    new_room_id,
+                    user_id,
+                )
+                continue
 
     @defer.inlineCallbacks
     def send_membership_event(self, requester, event, context, ratelimit=True):
@@ -759,22 +786,25 @@ class RoomMemberHandler(object):
         if room_avatar_event:
             room_avatar_url = room_avatar_event.content.get("url", "")
 
-        token, public_keys, fallback_public_key, display_name = (
-            yield self.identity_handler.ask_id_server_for_third_party_invite(
-                requester=requester,
-                id_server=id_server,
-                medium=medium,
-                address=address,
-                room_id=room_id,
-                inviter_user_id=user.to_string(),
-                room_alias=canonical_room_alias,
-                room_avatar_url=room_avatar_url,
-                room_join_rules=room_join_rules,
-                room_name=room_name,
-                inviter_display_name=inviter_display_name,
-                inviter_avatar_url=inviter_avatar_url,
-                id_access_token=id_access_token,
-            )
+        (
+            token,
+            public_keys,
+            fallback_public_key,
+            display_name,
+        ) = yield self.identity_handler.ask_id_server_for_third_party_invite(
+            requester=requester,
+            id_server=id_server,
+            medium=medium,
+            address=address,
+            room_id=room_id,
+            inviter_user_id=user.to_string(),
+            room_alias=canonical_room_alias,
+            room_avatar_url=room_avatar_url,
+            room_join_rules=room_join_rules,
+            room_name=room_name,
+            inviter_display_name=inviter_display_name,
+            inviter_avatar_url=inviter_avatar_url,
+            id_access_token=id_access_token,
         )
 
         yield self.event_creation_handler.create_and_send_nonmember_event(
diff --git a/synapse/handlers/search.py b/synapse/handlers/search.py
index cd5e90bacb..56ed262a1f 100644
--- a/synapse/handlers/search.py
+++ b/synapse/handlers/search.py
@@ -35,6 +35,8 @@ class SearchHandler(BaseHandler):
     def __init__(self, hs):
         super(SearchHandler, self).__init__(hs)
         self._event_serializer = hs.get_event_client_serializer()
+        self.storage = hs.get_storage()
+        self.state_store = self.storage.state
 
     @defer.inlineCallbacks
     def get_old_rooms_from_upgraded_room(self, room_id):
@@ -221,7 +223,7 @@ class SearchHandler(BaseHandler):
             filtered_events = search_filter.filter([r["event"] for r in results])
 
             events = yield filter_events_for_client(
-                self.store, user.to_string(), filtered_events
+                self.storage, user.to_string(), filtered_events
             )
 
             events.sort(key=lambda e: -rank_map[e.event_id])
@@ -271,7 +273,7 @@ class SearchHandler(BaseHandler):
                 filtered_events = search_filter.filter([r["event"] for r in results])
 
                 events = yield filter_events_for_client(
-                    self.store, user.to_string(), filtered_events
+                    self.storage, user.to_string(), filtered_events
                 )
 
                 room_events.extend(events)
@@ -340,11 +342,11 @@ class SearchHandler(BaseHandler):
                 )
 
                 res["events_before"] = yield filter_events_for_client(
-                    self.store, user.to_string(), res["events_before"]
+                    self.storage, user.to_string(), res["events_before"]
                 )
 
                 res["events_after"] = yield filter_events_for_client(
-                    self.store, user.to_string(), res["events_after"]
+                    self.storage, user.to_string(), res["events_after"]
                 )
 
                 res["start"] = now_token.copy_and_replace(
@@ -372,7 +374,7 @@ class SearchHandler(BaseHandler):
                         [(EventTypes.Member, sender) for sender in senders]
                     )
 
-                    state = yield self.store.get_state_for_event(
+                    state = yield self.state_store.get_state_for_event(
                         last_event_id, state_filter
                     )
 
@@ -394,15 +396,11 @@ class SearchHandler(BaseHandler):
         time_now = self.clock.time_msec()
 
         for context in contexts.values():
-            context["events_before"] = (
-                yield self._event_serializer.serialize_events(
-                    context["events_before"], time_now
-                )
+            context["events_before"] = yield self._event_serializer.serialize_events(
+                context["events_before"], time_now
             )
-            context["events_after"] = (
-                yield self._event_serializer.serialize_events(
-                    context["events_after"], time_now
-                )
+            context["events_after"] = yield self._event_serializer.serialize_events(
+                context["events_after"], time_now
             )
 
         state_results = {}
diff --git a/synapse/handlers/stats.py b/synapse/handlers/stats.py
index 26bc276692..7f7d56390e 100644
--- a/synapse/handlers/stats.py
+++ b/synapse/handlers/stats.py
@@ -108,7 +108,10 @@ class StatsHandler(StateDeltasHandler):
                 user_deltas = {}
 
             # Then count deltas for total_events and total_event_bytes.
-            room_count, user_count = yield self.store.get_changes_room_total_events_and_bytes(
+            (
+                room_count,
+                user_count,
+            ) = yield self.store.get_changes_room_total_events_and_bytes(
                 self.pos, max_pos
             )
 
diff --git a/synapse/handlers/sync.py b/synapse/handlers/sync.py
index d99160e9d7..b536d410e5 100644
--- a/synapse/handlers/sync.py
+++ b/synapse/handlers/sync.py
@@ -230,6 +230,8 @@ class SyncHandler(object):
         self.response_cache = ResponseCache(hs, "sync")
         self.state = hs.get_state_handler()
         self.auth = hs.get_auth()
+        self.storage = hs.get_storage()
+        self.state_store = self.storage.state
 
         # ExpiringCache((User, Device)) -> LruCache(state_key => event_id)
         self.lazy_loaded_members_cache = ExpiringCache(
@@ -417,7 +419,7 @@ class SyncHandler(object):
                     current_state_ids = frozenset(itervalues(current_state_ids))
 
                 recents = yield filter_events_for_client(
-                    self.store,
+                    self.storage,
                     sync_config.user.to_string(),
                     recents,
                     always_include_ids=current_state_ids,
@@ -470,7 +472,7 @@ class SyncHandler(object):
                     current_state_ids = frozenset(itervalues(current_state_ids))
 
                 loaded_recents = yield filter_events_for_client(
-                    self.store,
+                    self.storage,
                     sync_config.user.to_string(),
                     loaded_recents,
                     always_include_ids=current_state_ids,
@@ -509,7 +511,7 @@ class SyncHandler(object):
         Returns:
             A Deferred map from ((type, state_key)->Event)
         """
-        state_ids = yield self.store.get_state_ids_for_event(
+        state_ids = yield self.state_store.get_state_ids_for_event(
             event.event_id, state_filter=state_filter
         )
         if event.is_state():
@@ -580,7 +582,7 @@ class SyncHandler(object):
             return None
 
         last_event = last_events[-1]
-        state_ids = yield self.store.get_state_ids_for_event(
+        state_ids = yield self.state_store.get_state_ids_for_event(
             last_event.event_id,
             state_filter=StateFilter.from_types(
                 [(EventTypes.Name, ""), (EventTypes.CanonicalAlias, "")]
@@ -757,11 +759,11 @@ class SyncHandler(object):
 
             if full_state:
                 if batch:
-                    current_state_ids = yield self.store.get_state_ids_for_event(
+                    current_state_ids = yield self.state_store.get_state_ids_for_event(
                         batch.events[-1].event_id, state_filter=state_filter
                     )
 
-                    state_ids = yield self.store.get_state_ids_for_event(
+                    state_ids = yield self.state_store.get_state_ids_for_event(
                         batch.events[0].event_id, state_filter=state_filter
                     )
 
@@ -781,7 +783,7 @@ class SyncHandler(object):
                 )
             elif batch.limited:
                 if batch:
-                    state_at_timeline_start = yield self.store.get_state_ids_for_event(
+                    state_at_timeline_start = yield self.state_store.get_state_ids_for_event(
                         batch.events[0].event_id, state_filter=state_filter
                     )
                 else:
@@ -810,7 +812,7 @@ class SyncHandler(object):
                 )
 
                 if batch:
-                    current_state_ids = yield self.store.get_state_ids_for_event(
+                    current_state_ids = yield self.state_store.get_state_ids_for_event(
                         batch.events[-1].event_id, state_filter=state_filter
                     )
                 else:
@@ -841,7 +843,7 @@ class SyncHandler(object):
                         # So we fish out all the member events corresponding to the
                         # timeline here, and then dedupe any redundant ones below.
 
-                        state_ids = yield self.store.get_state_ids_for_event(
+                        state_ids = yield self.state_store.get_state_ids_for_event(
                             batch.events[0].event_id,
                             # we only want members!
                             state_filter=StateFilter.from_types(
@@ -1204,10 +1206,11 @@ class SyncHandler(object):
         since_token = sync_result_builder.since_token
 
         if since_token and not sync_result_builder.full_state:
-            account_data, account_data_by_room = (
-                yield self.store.get_updated_account_data_for_user(
-                    user_id, since_token.account_data_key
-                )
+            (
+                account_data,
+                account_data_by_room,
+            ) = yield self.store.get_updated_account_data_for_user(
+                user_id, since_token.account_data_key
             )
 
             push_rules_changed = yield self.store.have_push_rules_changed_for_user(
@@ -1219,9 +1222,10 @@ class SyncHandler(object):
                     sync_config.user
                 )
         else:
-            account_data, account_data_by_room = (
-                yield self.store.get_account_data_for_user(sync_config.user.to_string())
-            )
+            (
+                account_data,
+                account_data_by_room,
+            ) = yield self.store.get_account_data_for_user(sync_config.user.to_string())
 
             account_data["m.push_rules"] = yield self.push_rules_for_user(
                 sync_config.user
diff --git a/synapse/handlers/ui_auth/checkers.py b/synapse/handlers/ui_auth/checkers.py
index 29aa1e5aaf..8363d887a9 100644
--- a/synapse/handlers/ui_auth/checkers.py
+++ b/synapse/handlers/ui_auth/checkers.py
@@ -81,7 +81,7 @@ class RecaptchaAuthChecker(UserInteractiveAuthChecker):
     def __init__(self, hs):
         super().__init__(hs)
         self._enabled = bool(hs.config.recaptcha_private_key)
-        self._http_client = hs.get_simple_http_client()
+        self._http_client = hs.get_proxied_http_client()
         self._url = hs.config.recaptcha_siteverify_api
         self._secret = hs.config.recaptcha_private_key
 
diff --git a/synapse/http/client.py b/synapse/http/client.py
index cdf828a4ff..d4c285445e 100644
--- a/synapse/http/client.py
+++ b/synapse/http/client.py
@@ -45,6 +45,7 @@ from synapse.http import (
     cancelled_to_request_timed_out_error,
     redact_uri,
 )
+from synapse.http.proxyagent import ProxyAgent
 from synapse.logging.context import make_deferred_yieldable
 from synapse.logging.opentracing import set_tag, start_active_span, tags
 from synapse.util.async_helpers import timeout_deferred
@@ -183,7 +184,15 @@ class SimpleHttpClient(object):
     using HTTP in Matrix
     """
 
-    def __init__(self, hs, treq_args={}, ip_whitelist=None, ip_blacklist=None):
+    def __init__(
+        self,
+        hs,
+        treq_args={},
+        ip_whitelist=None,
+        ip_blacklist=None,
+        http_proxy=None,
+        https_proxy=None,
+    ):
         """
         Args:
             hs (synapse.server.HomeServer)
@@ -192,6 +201,8 @@ class SimpleHttpClient(object):
                 we may not request.
             ip_whitelist (netaddr.IPSet): The whitelisted IP addresses, that we can
                request if it were otherwise caught in a blacklist.
+            http_proxy (bytes): proxy server to use for http connections. host[:port]
+            https_proxy (bytes): proxy server to use for https connections. host[:port]
         """
         self.hs = hs
 
@@ -236,11 +247,13 @@ class SimpleHttpClient(object):
         # The default context factory in Twisted 14.0.0 (which we require) is
         # BrowserLikePolicyForHTTPS which will do regular cert validation
         # 'like a browser'
-        self.agent = Agent(
+        self.agent = ProxyAgent(
             self.reactor,
             connectTimeout=15,
             contextFactory=self.hs.get_http_client_context_factory(),
             pool=pool,
+            http_proxy=http_proxy,
+            https_proxy=https_proxy,
         )
 
         if self._ip_blacklist:
@@ -535,7 +548,7 @@ class SimpleHttpClient(object):
             b"Content-Length" in resp_headers
             and int(resp_headers[b"Content-Length"][0]) > max_size
         ):
-            logger.warn("Requested URL is too large > %r bytes" % (self.max_size,))
+            logger.warning("Requested URL is too large > %r bytes" % (self.max_size,))
             raise SynapseError(
                 502,
                 "Requested file is too large > %r bytes" % (self.max_size,),
@@ -543,7 +556,7 @@ class SimpleHttpClient(object):
             )
 
         if response.code > 299:
-            logger.warn("Got %d when downloading %s" % (response.code, url))
+            logger.warning("Got %d when downloading %s" % (response.code, url))
             raise SynapseError(502, "Got error %d" % (response.code,), Codes.UNKNOWN)
 
         # TODO: if our Content-Type is HTML or something, just read the first
diff --git a/synapse/http/connectproxyclient.py b/synapse/http/connectproxyclient.py
new file mode 100644
index 0000000000..be7b2ceb8e
--- /dev/null
+++ b/synapse/http/connectproxyclient.py
@@ -0,0 +1,195 @@
+# -*- coding: utf-8 -*-
+# Copyright 2019 The Matrix.org Foundation C.I.C.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import logging
+
+from zope.interface import implementer
+
+from twisted.internet import defer, protocol
+from twisted.internet.error import ConnectError
+from twisted.internet.interfaces import IStreamClientEndpoint
+from twisted.internet.protocol import connectionDone
+from twisted.web import http
+
+logger = logging.getLogger(__name__)
+
+
+class ProxyConnectError(ConnectError):
+    pass
+
+
+@implementer(IStreamClientEndpoint)
+class HTTPConnectProxyEndpoint(object):
+    """An Endpoint implementation which will send a CONNECT request to an http proxy
+
+    Wraps an existing HostnameEndpoint for the proxy.
+
+    When we get the connect() request from the connection pool (via the TLS wrapper),
+    we'll first connect to the proxy endpoint with a ProtocolFactory which will make the
+    CONNECT request. Once that completes, we invoke the protocolFactory which was passed
+    in.
+
+    Args:
+        reactor: the Twisted reactor to use for the connection
+        proxy_endpoint (IStreamClientEndpoint): the endpoint to use to connect to the
+            proxy
+        host (bytes): hostname that we want to CONNECT to
+        port (int): port that we want to connect to
+    """
+
+    def __init__(self, reactor, proxy_endpoint, host, port):
+        self._reactor = reactor
+        self._proxy_endpoint = proxy_endpoint
+        self._host = host
+        self._port = port
+
+    def __repr__(self):
+        return "<HTTPConnectProxyEndpoint %s>" % (self._proxy_endpoint,)
+
+    def connect(self, protocolFactory):
+        f = HTTPProxiedClientFactory(self._host, self._port, protocolFactory)
+        d = self._proxy_endpoint.connect(f)
+        # once the tcp socket connects successfully, we need to wait for the
+        # CONNECT to complete.
+        d.addCallback(lambda conn: f.on_connection)
+        return d
+
+
+class HTTPProxiedClientFactory(protocol.ClientFactory):
+    """ClientFactory wrapper that triggers an HTTP proxy CONNECT on connect.
+
+    Once the CONNECT completes, invokes the original ClientFactory to build the
+    HTTP Protocol object and run the rest of the connection.
+
+    Args:
+        dst_host (bytes): hostname that we want to CONNECT to
+        dst_port (int): port that we want to connect to
+        wrapped_factory (protocol.ClientFactory): The original Factory
+    """
+
+    def __init__(self, dst_host, dst_port, wrapped_factory):
+        self.dst_host = dst_host
+        self.dst_port = dst_port
+        self.wrapped_factory = wrapped_factory
+        self.on_connection = defer.Deferred()
+
+    def startedConnecting(self, connector):
+        return self.wrapped_factory.startedConnecting(connector)
+
+    def buildProtocol(self, addr):
+        wrapped_protocol = self.wrapped_factory.buildProtocol(addr)
+
+        return HTTPConnectProtocol(
+            self.dst_host, self.dst_port, wrapped_protocol, self.on_connection
+        )
+
+    def clientConnectionFailed(self, connector, reason):
+        logger.debug("Connection to proxy failed: %s", reason)
+        if not self.on_connection.called:
+            self.on_connection.errback(reason)
+        return self.wrapped_factory.clientConnectionFailed(connector, reason)
+
+    def clientConnectionLost(self, connector, reason):
+        logger.debug("Connection to proxy lost: %s", reason)
+        if not self.on_connection.called:
+            self.on_connection.errback(reason)
+        return self.wrapped_factory.clientConnectionLost(connector, reason)
+
+
+class HTTPConnectProtocol(protocol.Protocol):
+    """Protocol that wraps an existing Protocol to do a CONNECT handshake at connect
+
+    Args:
+        host (bytes): The original HTTP(s) hostname or IPv4 or IPv6 address literal
+            to put in the CONNECT request
+
+        port (int): The original HTTP(s) port to put in the CONNECT request
+
+        wrapped_protocol (interfaces.IProtocol): the original protocol (probably
+            HTTPChannel or TLSMemoryBIOProtocol, but could be anything really)
+
+        connected_deferred (Deferred): a Deferred which will be callbacked with
+            wrapped_protocol when the CONNECT completes
+    """
+
+    def __init__(self, host, port, wrapped_protocol, connected_deferred):
+        self.host = host
+        self.port = port
+        self.wrapped_protocol = wrapped_protocol
+        self.connected_deferred = connected_deferred
+        self.http_setup_client = HTTPConnectSetupClient(self.host, self.port)
+        self.http_setup_client.on_connected.addCallback(self.proxyConnected)
+
+    def connectionMade(self):
+        self.http_setup_client.makeConnection(self.transport)
+
+    def connectionLost(self, reason=connectionDone):
+        if self.wrapped_protocol.connected:
+            self.wrapped_protocol.connectionLost(reason)
+
+        self.http_setup_client.connectionLost(reason)
+
+        if not self.connected_deferred.called:
+            self.connected_deferred.errback(reason)
+
+    def proxyConnected(self, _):
+        self.wrapped_protocol.makeConnection(self.transport)
+
+        self.connected_deferred.callback(self.wrapped_protocol)
+
+        # Get any pending data from the http buf and forward it to the original protocol
+        buf = self.http_setup_client.clearLineBuffer()
+        if buf:
+            self.wrapped_protocol.dataReceived(buf)
+
+    def dataReceived(self, data):
+        # if we've set up the HTTP protocol, we can send the data there
+        if self.wrapped_protocol.connected:
+            return self.wrapped_protocol.dataReceived(data)
+
+        # otherwise, we must still be setting up the connection: send the data to the
+        # setup client
+        return self.http_setup_client.dataReceived(data)
+
+
+class HTTPConnectSetupClient(http.HTTPClient):
+    """HTTPClient protocol to send a CONNECT message for proxies and read the response.
+
+    Args:
+        host (bytes): The hostname to send in the CONNECT message
+        port (int): The port to send in the CONNECT message
+    """
+
+    def __init__(self, host, port):
+        self.host = host
+        self.port = port
+        self.on_connected = defer.Deferred()
+
+    def connectionMade(self):
+        logger.debug("Connected to proxy, sending CONNECT")
+        self.sendCommand(b"CONNECT", b"%s:%d" % (self.host, self.port))
+        self.endHeaders()
+
+    def handleStatus(self, version, status, message):
+        logger.debug("Got Status: %s %s %s", status, message, version)
+        if status != b"200":
+            raise ProxyConnectError("Unexpected status on CONNECT: %s" % status)
+
+    def handleEndHeaders(self):
+        logger.debug("End Headers")
+        self.on_connected.callback(None)
+
+    def handleResponse(self, body):
+        pass
diff --git a/synapse/http/federation/srv_resolver.py b/synapse/http/federation/srv_resolver.py
index 3fe4ffb9e5..021b233a7d 100644
--- a/synapse/http/federation/srv_resolver.py
+++ b/synapse/http/federation/srv_resolver.py
@@ -148,7 +148,7 @@ class SrvResolver(object):
             # Try something in the cache, else rereaise
             cache_entry = self._cache.get(service_name, None)
             if cache_entry:
-                logger.warn(
+                logger.warning(
                     "Failed to resolve %r, falling back to cache. %r", service_name, e
                 )
                 return list(cache_entry)
diff --git a/synapse/http/matrixfederationclient.py b/synapse/http/matrixfederationclient.py
index 3f7c93ffcb..691380abda 100644
--- a/synapse/http/matrixfederationclient.py
+++ b/synapse/http/matrixfederationclient.py
@@ -149,7 +149,7 @@ def _handle_json_response(reactor, timeout_sec, request, response):
 
         body = yield make_deferred_yieldable(d)
     except Exception as e:
-        logger.warn(
+        logger.warning(
             "{%s} [%s] Error reading response: %s",
             request.txn_id,
             request.destination,
@@ -457,7 +457,7 @@ class MatrixFederationHttpClient(object):
                         except Exception as e:
                             # Eh, we're already going to raise an exception so lets
                             # ignore if this fails.
-                            logger.warn(
+                            logger.warning(
                                 "{%s} [%s] Failed to get error response: %s %s: %s",
                                 request.txn_id,
                                 request.destination,
@@ -478,7 +478,7 @@ class MatrixFederationHttpClient(object):
 
                     break
                 except RequestSendFailed as e:
-                    logger.warn(
+                    logger.warning(
                         "{%s} [%s] Request failed: %s %s: %s",
                         request.txn_id,
                         request.destination,
@@ -513,7 +513,7 @@ class MatrixFederationHttpClient(object):
                         raise
 
                 except Exception as e:
-                    logger.warn(
+                    logger.warning(
                         "{%s} [%s] Request failed: %s %s: %s",
                         request.txn_id,
                         request.destination,
@@ -889,7 +889,7 @@ class MatrixFederationHttpClient(object):
             d.addTimeout(self.default_timeout, self.reactor)
             length = yield make_deferred_yieldable(d)
         except Exception as e:
-            logger.warn(
+            logger.warning(
                 "{%s} [%s] Error reading response: %s",
                 request.txn_id,
                 request.destination,
diff --git a/synapse/http/proxyagent.py b/synapse/http/proxyagent.py
new file mode 100644
index 0000000000..332da02a8d
--- /dev/null
+++ b/synapse/http/proxyagent.py
@@ -0,0 +1,195 @@
+# -*- coding: utf-8 -*-
+# Copyright 2019 The Matrix.org Foundation C.I.C.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+import logging
+import re
+
+from zope.interface import implementer
+
+from twisted.internet import defer
+from twisted.internet.endpoints import HostnameEndpoint, wrapClientTLS
+from twisted.python.failure import Failure
+from twisted.web.client import URI, BrowserLikePolicyForHTTPS, _AgentBase
+from twisted.web.error import SchemeNotSupported
+from twisted.web.iweb import IAgent
+
+from synapse.http.connectproxyclient import HTTPConnectProxyEndpoint
+
+logger = logging.getLogger(__name__)
+
+_VALID_URI = re.compile(br"\A[\x21-\x7e]+\Z")
+
+
+@implementer(IAgent)
+class ProxyAgent(_AgentBase):
+    """An Agent implementation which will use an HTTP proxy if one was requested
+
+    Args:
+        reactor: twisted reactor to place outgoing
+            connections.
+
+        contextFactory (IPolicyForHTTPS): A factory for TLS contexts, to control the
+            verification parameters of OpenSSL.  The default is to use a
+            `BrowserLikePolicyForHTTPS`, so unless you have special
+            requirements you can leave this as-is.
+
+        connectTimeout (float): The amount of time that this Agent will wait
+            for the peer to accept a connection.
+
+        bindAddress (bytes): The local address for client sockets to bind to.
+
+        pool (HTTPConnectionPool|None): connection pool to be used. If None, a
+            non-persistent pool instance will be created.
+    """
+
+    def __init__(
+        self,
+        reactor,
+        contextFactory=BrowserLikePolicyForHTTPS(),
+        connectTimeout=None,
+        bindAddress=None,
+        pool=None,
+        http_proxy=None,
+        https_proxy=None,
+    ):
+        _AgentBase.__init__(self, reactor, pool)
+
+        self._endpoint_kwargs = {}
+        if connectTimeout is not None:
+            self._endpoint_kwargs["timeout"] = connectTimeout
+        if bindAddress is not None:
+            self._endpoint_kwargs["bindAddress"] = bindAddress
+
+        self.http_proxy_endpoint = _http_proxy_endpoint(
+            http_proxy, reactor, **self._endpoint_kwargs
+        )
+
+        self.https_proxy_endpoint = _http_proxy_endpoint(
+            https_proxy, reactor, **self._endpoint_kwargs
+        )
+
+        self._policy_for_https = contextFactory
+        self._reactor = reactor
+
+    def request(self, method, uri, headers=None, bodyProducer=None):
+        """
+        Issue a request to the server indicated by the given uri.
+
+        Supports `http` and `https` schemes.
+
+        An existing connection from the connection pool may be used or a new one may be
+        created.
+
+        See also: twisted.web.iweb.IAgent.request
+
+        Args:
+            method (bytes): The request method to use, such as `GET`, `POST`, etc
+
+            uri (bytes): The location of the resource to request.
+
+            headers (Headers|None): Extra headers to send with the request
+
+            bodyProducer (IBodyProducer|None): An object which can generate bytes to
+                make up the body of this request (for example, the properly encoded
+                contents of a file for a file upload). Or, None if the request is to
+                have no body.
+
+        Returns:
+            Deferred[IResponse]: completes when the header of the response has
+                 been received (regardless of the response status code).
+        """
+        uri = uri.strip()
+        if not _VALID_URI.match(uri):
+            raise ValueError("Invalid URI {!r}".format(uri))
+
+        parsed_uri = URI.fromBytes(uri)
+        pool_key = (parsed_uri.scheme, parsed_uri.host, parsed_uri.port)
+        request_path = parsed_uri.originForm
+
+        if parsed_uri.scheme == b"http" and self.http_proxy_endpoint:
+            # Cache *all* connections under the same key, since we are only
+            # connecting to a single destination, the proxy:
+            pool_key = ("http-proxy", self.http_proxy_endpoint)
+            endpoint = self.http_proxy_endpoint
+            request_path = uri
+        elif parsed_uri.scheme == b"https" and self.https_proxy_endpoint:
+            endpoint = HTTPConnectProxyEndpoint(
+                self._reactor,
+                self.https_proxy_endpoint,
+                parsed_uri.host,
+                parsed_uri.port,
+            )
+        else:
+            # not using a proxy
+            endpoint = HostnameEndpoint(
+                self._reactor, parsed_uri.host, parsed_uri.port, **self._endpoint_kwargs
+            )
+
+        logger.debug("Requesting %s via %s", uri, endpoint)
+
+        if parsed_uri.scheme == b"https":
+            tls_connection_creator = self._policy_for_https.creatorForNetloc(
+                parsed_uri.host, parsed_uri.port
+            )
+            endpoint = wrapClientTLS(tls_connection_creator, endpoint)
+        elif parsed_uri.scheme == b"http":
+            pass
+        else:
+            return defer.fail(
+                Failure(
+                    SchemeNotSupported("Unsupported scheme: %r" % (parsed_uri.scheme,))
+                )
+            )
+
+        return self._requestWithEndpoint(
+            pool_key, endpoint, method, parsed_uri, headers, bodyProducer, request_path
+        )
+
+
+def _http_proxy_endpoint(proxy, reactor, **kwargs):
+    """Parses an http proxy setting and returns an endpoint for the proxy
+
+    Args:
+        proxy (bytes|None):  the proxy setting
+        reactor: reactor to be used to connect to the proxy
+        kwargs: other args to be passed to HostnameEndpoint
+
+    Returns:
+        interfaces.IStreamClientEndpoint|None: endpoint to use to connect to the proxy,
+            or None
+    """
+    if proxy is None:
+        return None
+
+    # currently we only support hostname:port. Some apps also support
+    # protocol://<host>[:port], which allows a way of requiring a TLS connection to the
+    # proxy.
+
+    host, port = parse_host_port(proxy, default_port=1080)
+    return HostnameEndpoint(reactor, host, port, **kwargs)
+
+
+def parse_host_port(hostport, default_port=None):
+    # could have sworn we had one of these somewhere else...
+    if b":" in hostport:
+        host, port = hostport.rsplit(b":", 1)
+        try:
+            port = int(port)
+            return host, port
+        except ValueError:
+            # the thing after the : wasn't a valid port; presumably this is an
+            # IPv6 address.
+            pass
+
+    return hostport, default_port
diff --git a/synapse/http/request_metrics.py b/synapse/http/request_metrics.py
index 46af27c8f6..58f9cc61c8 100644
--- a/synapse/http/request_metrics.py
+++ b/synapse/http/request_metrics.py
@@ -170,7 +170,7 @@ class RequestMetrics(object):
             tag = context.tag
 
             if context != self.start_context:
-                logger.warn(
+                logger.warning(
                     "Context have unexpectedly changed %r, %r",
                     context,
                     self.start_context,
diff --git a/synapse/http/server.py b/synapse/http/server.py
index 2ccb210fd6..943d12c907 100644
--- a/synapse/http/server.py
+++ b/synapse/http/server.py
@@ -454,7 +454,7 @@ def respond_with_json(
     # the Deferred fires, but since the flag is RIGHT THERE it seems like
     # a waste.
     if request._disconnected:
-        logger.warn(
+        logger.warning(
             "Not sending response to request %s, already disconnected.", request
         )
         return
diff --git a/synapse/http/servlet.py b/synapse/http/servlet.py
index 274c1a6a87..e9a5e46ced 100644
--- a/synapse/http/servlet.py
+++ b/synapse/http/servlet.py
@@ -219,13 +219,13 @@ def parse_json_value_from_request(request, allow_empty_body=False):
     try:
         content_unicode = content_bytes.decode("utf8")
     except UnicodeDecodeError:
-        logger.warn("Unable to decode UTF-8")
+        logger.warning("Unable to decode UTF-8")
         raise SynapseError(400, "Content not JSON.", errcode=Codes.NOT_JSON)
 
     try:
         content = json.loads(content_unicode)
     except Exception as e:
-        logger.warn("Unable to parse JSON: %s", e)
+        logger.warning("Unable to parse JSON: %s", e)
         raise SynapseError(400, "Content not JSON.", errcode=Codes.NOT_JSON)
 
     return content
diff --git a/synapse/http/site.py b/synapse/http/site.py
index df5274c177..ff8184a3d0 100644
--- a/synapse/http/site.py
+++ b/synapse/http/site.py
@@ -199,7 +199,7 @@ class SynapseRequest(Request):
         # It's useful to log it here so that we can get an idea of when
         # the client disconnects.
         with PreserveLoggingContext(self.logcontext):
-            logger.warn(
+            logger.warning(
                 "Error processing request %r: %s %s", self, reason.type, reason.value
             )
 
@@ -305,7 +305,7 @@ class SynapseRequest(Request):
         try:
             self.request_metrics.stop(self.finish_time, self.code, self.sentLength)
         except Exception as e:
-            logger.warn("Failed to stop metrics: %r", e)
+            logger.warning("Failed to stop metrics: %r", e)
 
 
 class XForwardedForRequest(SynapseRequest):
diff --git a/synapse/logging/_structured.py b/synapse/logging/_structured.py
index 3220e985a9..334ddaf39a 100644
--- a/synapse/logging/_structured.py
+++ b/synapse/logging/_structured.py
@@ -185,7 +185,7 @@ DEFAULT_LOGGERS = {"synapse": {"level": "INFO"}}
 
 
 def parse_drain_configs(
-    drains: dict
+    drains: dict,
 ) -> typing.Generator[DrainConfiguration, None, None]:
     """
     Parse the drain configurations.
diff --git a/synapse/logging/context.py b/synapse/logging/context.py
index 370000e377..2c1fb9ddac 100644
--- a/synapse/logging/context.py
+++ b/synapse/logging/context.py
@@ -294,7 +294,7 @@ class LoggingContext(object):
         """Enters this logging context into thread local storage"""
         old_context = self.set_current_context(self)
         if self.previous_context != old_context:
-            logger.warn(
+            logger.warning(
                 "Expected previous context %r, found %r",
                 self.previous_context,
                 old_context,
diff --git a/synapse/notifier.py b/synapse/notifier.py
index 4e091314e6..af161a81d7 100644
--- a/synapse/notifier.py
+++ b/synapse/notifier.py
@@ -159,6 +159,7 @@ class Notifier(object):
         self.room_to_user_streams = {}
 
         self.hs = hs
+        self.storage = hs.get_storage()
         self.event_sources = hs.get_event_sources()
         self.store = hs.get_datastore()
         self.pending_new_room_events = []
@@ -425,7 +426,10 @@ class Notifier(object):
 
                 if name == "room":
                     new_events = yield filter_events_for_client(
-                        self.store, user.to_string(), new_events, is_peeking=is_peeking
+                        self.storage,
+                        user.to_string(),
+                        new_events,
+                        is_peeking=is_peeking,
                     )
                 elif name == "presence":
                     now = self.clock.time_msec()
diff --git a/synapse/push/bulk_push_rule_evaluator.py b/synapse/push/bulk_push_rule_evaluator.py
index 22491f3700..1ba7bcd4d8 100644
--- a/synapse/push/bulk_push_rule_evaluator.py
+++ b/synapse/push/bulk_push_rule_evaluator.py
@@ -79,7 +79,7 @@ class BulkPushRuleEvaluator(object):
             dict of user_id -> push_rules
         """
         room_id = event.room_id
-        rules_for_room = self._get_rules_for_room(room_id)
+        rules_for_room = yield self._get_rules_for_room(room_id)
 
         rules_by_user = yield rules_for_room.get_rules(event, context)
 
@@ -149,9 +149,10 @@ class BulkPushRuleEvaluator(object):
 
         room_members = yield self.store.get_joined_users_from_context(event, context)
 
-        (power_levels, sender_power_level) = (
-            yield self._get_power_levels_and_sender_level(event, context)
-        )
+        (
+            power_levels,
+            sender_power_level,
+        ) = yield self._get_power_levels_and_sender_level(event, context)
 
         evaluator = PushRuleEvaluatorForEvent(
             event, len(room_members), sender_power_level, power_levels
diff --git a/synapse/push/emailpusher.py b/synapse/push/emailpusher.py
index 42e5b0c0a5..8c818a86bf 100644
--- a/synapse/push/emailpusher.py
+++ b/synapse/push/emailpusher.py
@@ -234,14 +234,12 @@ class EmailPusher(object):
             return
 
         self.last_stream_ordering = last_stream_ordering
-        pusher_still_exists = (
-            yield self.store.update_pusher_last_stream_ordering_and_success(
-                self.app_id,
-                self.email,
-                self.user_id,
-                last_stream_ordering,
-                self.clock.time_msec(),
-            )
+        pusher_still_exists = yield self.store.update_pusher_last_stream_ordering_and_success(
+            self.app_id,
+            self.email,
+            self.user_id,
+            last_stream_ordering,
+            self.clock.time_msec(),
         )
         if not pusher_still_exists:
             # The pusher has been deleted while we were processing, so
diff --git a/synapse/push/httppusher.py b/synapse/push/httppusher.py
index 6299587808..e994037be6 100644
--- a/synapse/push/httppusher.py
+++ b/synapse/push/httppusher.py
@@ -64,6 +64,7 @@ class HttpPusher(object):
     def __init__(self, hs, pusherdict):
         self.hs = hs
         self.store = self.hs.get_datastore()
+        self.storage = self.hs.get_storage()
         self.clock = self.hs.get_clock()
         self.state_handler = self.hs.get_state_handler()
         self.user_id = pusherdict["user_name"]
@@ -102,7 +103,7 @@ class HttpPusher(object):
         if "url" not in self.data:
             raise PusherConfigException("'url' required in data for HTTP pusher")
         self.url = self.data["url"]
-        self.http_client = hs.get_simple_http_client()
+        self.http_client = hs.get_proxied_http_client()
         self.data_minus_url = {}
         self.data_minus_url.update(self.data)
         del self.data_minus_url["url"]
@@ -210,14 +211,12 @@ class HttpPusher(object):
                 http_push_processed_counter.inc()
                 self.backoff_delay = HttpPusher.INITIAL_BACKOFF_SEC
                 self.last_stream_ordering = push_action["stream_ordering"]
-                pusher_still_exists = (
-                    yield self.store.update_pusher_last_stream_ordering_and_success(
-                        self.app_id,
-                        self.pushkey,
-                        self.user_id,
-                        self.last_stream_ordering,
-                        self.clock.time_msec(),
-                    )
+                pusher_still_exists = yield self.store.update_pusher_last_stream_ordering_and_success(
+                    self.app_id,
+                    self.pushkey,
+                    self.user_id,
+                    self.last_stream_ordering,
+                    self.clock.time_msec(),
                 )
                 if not pusher_still_exists:
                     # The pusher has been deleted while we were processing, so
@@ -246,7 +245,7 @@ class HttpPusher(object):
                     # we really only give up so that if the URL gets
                     # fixed, we don't suddenly deliver a load
                     # of old notifications.
-                    logger.warn(
+                    logger.warning(
                         "Giving up on a notification to user %s, " "pushkey %s",
                         self.user_id,
                         self.pushkey,
@@ -299,7 +298,7 @@ class HttpPusher(object):
                 if pk != self.pushkey:
                     # for sanity, we only remove the pushkey if it
                     # was the one we actually sent...
-                    logger.warn(
+                    logger.warning(
                         ("Ignoring rejected pushkey %s because we" " didn't send it"),
                         pk,
                     )
@@ -329,7 +328,7 @@ class HttpPusher(object):
             return d
 
         ctx = yield push_tools.get_context_for_event(
-            self.store, self.state_handler, event, self.user_id
+            self.storage, self.state_handler, event, self.user_id
         )
 
         d = {
diff --git a/synapse/push/mailer.py b/synapse/push/mailer.py
index 5b16ab4ae8..1d15a06a58 100644
--- a/synapse/push/mailer.py
+++ b/synapse/push/mailer.py
@@ -119,6 +119,7 @@ class Mailer(object):
         self.store = self.hs.get_datastore()
         self.macaroon_gen = self.hs.get_macaroon_generator()
         self.state_handler = self.hs.get_state_handler()
+        self.storage = hs.get_storage()
         self.app_name = app_name
 
         logger.info("Created Mailer for app_name %s" % app_name)
@@ -389,7 +390,7 @@ class Mailer(object):
         }
 
         the_events = yield filter_events_for_client(
-            self.store, user_id, results["events_before"]
+            self.storage, user_id, results["events_before"]
         )
         the_events.append(notif_event)
 
diff --git a/synapse/push/push_rule_evaluator.py b/synapse/push/push_rule_evaluator.py
index 5ed9147de4..b1587183a8 100644
--- a/synapse/push/push_rule_evaluator.py
+++ b/synapse/push/push_rule_evaluator.py
@@ -117,7 +117,7 @@ class PushRuleEvaluatorForEvent(object):
                 pattern = UserID.from_string(user_id).localpart
 
         if not pattern:
-            logger.warn("event_match condition with no pattern")
+            logger.warning("event_match condition with no pattern")
             return False
 
         # XXX: optimisation: cache our pattern regexps
@@ -173,7 +173,7 @@ def _glob_matches(glob, value, word_boundary=False):
             regex_cache[(glob, word_boundary)] = r
         return r.search(value)
     except re.error:
-        logger.warn("Failed to parse glob to regex: %r", glob)
+        logger.warning("Failed to parse glob to regex: %r", glob)
         return False
 
 
diff --git a/synapse/push/push_tools.py b/synapse/push/push_tools.py
index a54051a726..de5c101a58 100644
--- a/synapse/push/push_tools.py
+++ b/synapse/push/push_tools.py
@@ -16,6 +16,7 @@
 from twisted.internet import defer
 
 from synapse.push.presentable_names import calculate_room_name, name_from_member_event
+from synapse.storage import Storage
 
 
 @defer.inlineCallbacks
@@ -43,22 +44,22 @@ def get_badge_count(store, user_id):
 
 
 @defer.inlineCallbacks
-def get_context_for_event(store, state_handler, ev, user_id):
+def get_context_for_event(storage: Storage, state_handler, ev, user_id):
     ctx = {}
 
-    room_state_ids = yield store.get_state_ids_for_event(ev.event_id)
+    room_state_ids = yield storage.state.get_state_ids_for_event(ev.event_id)
 
     # we no longer bother setting room_alias, and make room_name the
     # human-readable name instead, be that m.room.name, an alias or
     # a list of people in the room
     name = yield calculate_room_name(
-        store, room_state_ids, user_id, fallback_to_single_member=False
+        storage.main, room_state_ids, user_id, fallback_to_single_member=False
     )
     if name:
         ctx["name"] = name
 
     sender_state_event_id = room_state_ids[("m.room.member", ev.sender)]
-    sender_state_event = yield store.get_event(sender_state_event_id)
+    sender_state_event = yield storage.main.get_event(sender_state_event_id)
     ctx["sender_display_name"] = name_from_member_event(sender_state_event)
 
     return ctx
diff --git a/synapse/push/pusherpool.py b/synapse/push/pusherpool.py
index 08e840fdc2..0f6992202d 100644
--- a/synapse/push/pusherpool.py
+++ b/synapse/push/pusherpool.py
@@ -103,9 +103,7 @@ class PusherPool:
         # create the pusher setting last_stream_ordering to the current maximum
         # stream ordering in event_push_actions, so it will process
         # pushes from this point onwards.
-        last_stream_ordering = (
-            yield self.store.get_latest_push_action_stream_ordering()
-        )
+        last_stream_ordering = yield self.store.get_latest_push_action_stream_ordering()
 
         yield self.store.add_pusher(
             user_id=user_id,
diff --git a/synapse/python_dependencies.py b/synapse/python_dependencies.py
index aa7da1c543..5871feaafd 100644
--- a/synapse/python_dependencies.py
+++ b/synapse/python_dependencies.py
@@ -61,7 +61,6 @@ REQUIREMENTS = [
     "bcrypt>=3.1.0",
     "pillow>=4.3.0",
     "sortedcontainers>=1.4.4",
-    "psutil>=2.0.0",
     "pymacaroons>=0.13.0",
     "msgpack>=0.5.2",
     "phonenumbers>=8.2.0",
diff --git a/synapse/replication/http/_base.py b/synapse/replication/http/_base.py
index 03560c1f0e..c8056b0c0c 100644
--- a/synapse/replication/http/_base.py
+++ b/synapse/replication/http/_base.py
@@ -110,14 +110,14 @@ class ReplicationEndpoint(object):
         return {}
 
     @abc.abstractmethod
-    def _handle_request(self, request, **kwargs):
+    async def _handle_request(self, request, **kwargs):
         """Handle incoming request.
 
         This is called with the request object and PATH_ARGS.
 
         Returns:
-            Deferred[dict]: A JSON serialisable dict to be used as response
-            body of request.
+            tuple[int, dict]: HTTP status code and a JSON serialisable dict
+            to be used as response body of request.
         """
         pass
 
@@ -180,7 +180,7 @@ class ReplicationEndpoint(object):
                         if e.code != 504 or not cls.RETRY_ON_TIMEOUT:
                             raise
 
-                    logger.warn("%s request timed out", cls.NAME)
+                    logger.warning("%s request timed out", cls.NAME)
 
                     # If we timed out we probably don't need to worry about backing
                     # off too much, but lets just wait a little anyway.
diff --git a/synapse/replication/http/federation.py b/synapse/replication/http/federation.py
index 2f16955954..9af4e7e173 100644
--- a/synapse/replication/http/federation.py
+++ b/synapse/replication/http/federation.py
@@ -82,8 +82,7 @@ class ReplicationFederationSendEventsRestServlet(ReplicationEndpoint):
 
         return payload
 
-    @defer.inlineCallbacks
-    def _handle_request(self, request):
+    async def _handle_request(self, request):
         with Measure(self.clock, "repl_fed_send_events_parse"):
             content = parse_json_object_from_request(request)
 
@@ -101,15 +100,13 @@ class ReplicationFederationSendEventsRestServlet(ReplicationEndpoint):
                 EventType = event_type_from_format_version(format_ver)
                 event = EventType(event_dict, internal_metadata, rejected_reason)
 
-                context = yield EventContext.deserialize(
-                    self.store, event_payload["context"]
-                )
+                context = EventContext.deserialize(self.store, event_payload["context"])
 
                 event_and_contexts.append((event, context))
 
         logger.info("Got %d events from federation", len(event_and_contexts))
 
-        yield self.federation_handler.persist_events_and_notify(
+        await self.federation_handler.persist_events_and_notify(
             event_and_contexts, backfilled
         )
 
@@ -144,8 +141,7 @@ class ReplicationFederationSendEduRestServlet(ReplicationEndpoint):
     def _serialize_payload(edu_type, origin, content):
         return {"origin": origin, "content": content}
 
-    @defer.inlineCallbacks
-    def _handle_request(self, request, edu_type):
+    async def _handle_request(self, request, edu_type):
         with Measure(self.clock, "repl_fed_send_edu_parse"):
             content = parse_json_object_from_request(request)
 
@@ -154,7 +150,7 @@ class ReplicationFederationSendEduRestServlet(ReplicationEndpoint):
 
         logger.info("Got %r edu from %s", edu_type, origin)
 
-        result = yield self.registry.on_edu(edu_type, origin, edu_content)
+        result = await self.registry.on_edu(edu_type, origin, edu_content)
 
         return 200, result
 
@@ -193,8 +189,7 @@ class ReplicationGetQueryRestServlet(ReplicationEndpoint):
         """
         return {"args": args}
 
-    @defer.inlineCallbacks
-    def _handle_request(self, request, query_type):
+    async def _handle_request(self, request, query_type):
         with Measure(self.clock, "repl_fed_query_parse"):
             content = parse_json_object_from_request(request)
 
@@ -202,7 +197,7 @@ class ReplicationGetQueryRestServlet(ReplicationEndpoint):
 
         logger.info("Got %r query", query_type)
 
-        result = yield self.registry.on_query(query_type, args)
+        result = await self.registry.on_query(query_type, args)
 
         return 200, result
 
@@ -234,9 +229,8 @@ class ReplicationCleanRoomRestServlet(ReplicationEndpoint):
         """
         return {}
 
-    @defer.inlineCallbacks
-    def _handle_request(self, request, room_id):
-        yield self.store.clean_room_for_join(room_id)
+    async def _handle_request(self, request, room_id):
+        await self.store.clean_room_for_join(room_id)
 
         return 200, {}
 
diff --git a/synapse/replication/http/login.py b/synapse/replication/http/login.py
index 786f5232b2..798b9d3af5 100644
--- a/synapse/replication/http/login.py
+++ b/synapse/replication/http/login.py
@@ -15,8 +15,6 @@
 
 import logging
 
-from twisted.internet import defer
-
 from synapse.http.servlet import parse_json_object_from_request
 from synapse.replication.http._base import ReplicationEndpoint
 
@@ -52,15 +50,14 @@ class RegisterDeviceReplicationServlet(ReplicationEndpoint):
             "is_guest": is_guest,
         }
 
-    @defer.inlineCallbacks
-    def _handle_request(self, request, user_id):
+    async def _handle_request(self, request, user_id):
         content = parse_json_object_from_request(request)
 
         device_id = content["device_id"]
         initial_display_name = content["initial_display_name"]
         is_guest = content["is_guest"]
 
-        device_id, access_token = yield self.registration_handler.register_device(
+        device_id, access_token = await self.registration_handler.register_device(
             user_id, device_id, initial_display_name, is_guest
         )
 
diff --git a/synapse/replication/http/membership.py b/synapse/replication/http/membership.py
index b9ce3477ad..cc1f249740 100644
--- a/synapse/replication/http/membership.py
+++ b/synapse/replication/http/membership.py
@@ -15,8 +15,6 @@
 
 import logging
 
-from twisted.internet import defer
-
 from synapse.http.servlet import parse_json_object_from_request
 from synapse.replication.http._base import ReplicationEndpoint
 from synapse.types import Requester, UserID
@@ -65,8 +63,7 @@ class ReplicationRemoteJoinRestServlet(ReplicationEndpoint):
             "content": content,
         }
 
-    @defer.inlineCallbacks
-    def _handle_request(self, request, room_id, user_id):
+    async def _handle_request(self, request, room_id, user_id):
         content = parse_json_object_from_request(request)
 
         remote_room_hosts = content["remote_room_hosts"]
@@ -79,7 +76,7 @@ class ReplicationRemoteJoinRestServlet(ReplicationEndpoint):
 
         logger.info("remote_join: %s into room: %s", user_id, room_id)
 
-        yield self.federation_handler.do_invite_join(
+        await self.federation_handler.do_invite_join(
             remote_room_hosts, room_id, user_id, event_content
         )
 
@@ -123,8 +120,7 @@ class ReplicationRemoteRejectInviteRestServlet(ReplicationEndpoint):
             "remote_room_hosts": remote_room_hosts,
         }
 
-    @defer.inlineCallbacks
-    def _handle_request(self, request, room_id, user_id):
+    async def _handle_request(self, request, room_id, user_id):
         content = parse_json_object_from_request(request)
 
         remote_room_hosts = content["remote_room_hosts"]
@@ -137,7 +133,7 @@ class ReplicationRemoteRejectInviteRestServlet(ReplicationEndpoint):
         logger.info("remote_reject_invite: %s out of room: %s", user_id, room_id)
 
         try:
-            event = yield self.federation_handler.do_remotely_reject_invite(
+            event = await self.federation_handler.do_remotely_reject_invite(
                 remote_room_hosts, room_id, user_id
             )
             ret = event.get_pdu_json()
@@ -148,9 +144,9 @@ class ReplicationRemoteRejectInviteRestServlet(ReplicationEndpoint):
             # The 'except' clause is very broad, but we need to
             # capture everything from DNS failures upwards
             #
-            logger.warn("Failed to reject invite: %s", e)
+            logger.warning("Failed to reject invite: %s", e)
 
-            yield self.store.locally_reject_invite(user_id, room_id)
+            await self.store.locally_reject_invite(user_id, room_id)
             ret = {}
 
         return 200, ret
diff --git a/synapse/replication/http/register.py b/synapse/replication/http/register.py
index 38260256cf..915cfb9430 100644
--- a/synapse/replication/http/register.py
+++ b/synapse/replication/http/register.py
@@ -15,8 +15,6 @@
 
 import logging
 
-from twisted.internet import defer
-
 from synapse.http.servlet import parse_json_object_from_request
 from synapse.replication.http._base import ReplicationEndpoint
 
@@ -74,11 +72,10 @@ class ReplicationRegisterServlet(ReplicationEndpoint):
             "address": address,
         }
 
-    @defer.inlineCallbacks
-    def _handle_request(self, request, user_id):
+    async def _handle_request(self, request, user_id):
         content = parse_json_object_from_request(request)
 
-        yield self.registration_handler.register_with_store(
+        await self.registration_handler.register_with_store(
             user_id=user_id,
             password_hash=content["password_hash"],
             was_guest=content["was_guest"],
@@ -117,14 +114,13 @@ class ReplicationPostRegisterActionsServlet(ReplicationEndpoint):
         """
         return {"auth_result": auth_result, "access_token": access_token}
 
-    @defer.inlineCallbacks
-    def _handle_request(self, request, user_id):
+    async def _handle_request(self, request, user_id):
         content = parse_json_object_from_request(request)
 
         auth_result = content["auth_result"]
         access_token = content["access_token"]
 
-        yield self.registration_handler.post_registration_actions(
+        await self.registration_handler.post_registration_actions(
             user_id=user_id, auth_result=auth_result, access_token=access_token
         )
 
diff --git a/synapse/replication/http/send_event.py b/synapse/replication/http/send_event.py
index adb9b2f7f4..9bafd60b14 100644
--- a/synapse/replication/http/send_event.py
+++ b/synapse/replication/http/send_event.py
@@ -87,8 +87,7 @@ class ReplicationSendEventRestServlet(ReplicationEndpoint):
 
         return payload
 
-    @defer.inlineCallbacks
-    def _handle_request(self, request, event_id):
+    async def _handle_request(self, request, event_id):
         with Measure(self.clock, "repl_send_event_parse"):
             content = parse_json_object_from_request(request)
 
@@ -101,7 +100,7 @@ class ReplicationSendEventRestServlet(ReplicationEndpoint):
             event = EventType(event_dict, internal_metadata, rejected_reason)
 
             requester = Requester.deserialize(self.store, content["requester"])
-            context = yield EventContext.deserialize(self.store, content["context"])
+            context = EventContext.deserialize(self.store, content["context"])
 
             ratelimit = content["ratelimit"]
             extra_users = [UserID.from_string(u) for u in content["extra_users"]]
@@ -113,7 +112,7 @@ class ReplicationSendEventRestServlet(ReplicationEndpoint):
             "Got event to send with ID: %s into room: %s", event.event_id, event.room_id
         )
 
-        yield self.event_creation_handler.persist_and_notify_client_event(
+        await self.event_creation_handler.persist_and_notify_client_event(
             requester, event, context, ratelimit=ratelimit, extra_users=extra_users
         )
 
diff --git a/synapse/replication/slave/storage/_base.py b/synapse/replication/slave/storage/_base.py
index 182cb2a1d8..456bc005a0 100644
--- a/synapse/replication/slave/storage/_base.py
+++ b/synapse/replication/slave/storage/_base.py
@@ -14,6 +14,7 @@
 # limitations under the License.
 
 import logging
+from typing import Dict
 
 import six
 
@@ -44,7 +45,14 @@ class BaseSlavedStore(SQLBaseStore):
 
         self.hs = hs
 
-    def stream_positions(self):
+    def stream_positions(self) -> Dict[str, int]:
+        """
+        Get the current positions of all the streams this store wants to subscribe to
+
+        Returns:
+            map from stream name to the most recent update we have for
+            that stream (ie, the point we want to start replicating from)
+        """
         pos = {}
         if self._cache_id_gen:
             pos["caches"] = self._cache_id_gen.get_current_token()
diff --git a/synapse/replication/slave/storage/devices.py b/synapse/replication/slave/storage/devices.py
index 61557665a7..de50748c30 100644
--- a/synapse/replication/slave/storage/devices.py
+++ b/synapse/replication/slave/storage/devices.py
@@ -15,6 +15,7 @@
 
 from synapse.replication.slave.storage._base import BaseSlavedStore
 from synapse.replication.slave.storage._slaved_id_tracker import SlavedIdTracker
+from synapse.replication.tcp.streams._base import DeviceListsStream, UserSignatureStream
 from synapse.storage.data_stores.main.devices import DeviceWorkerStore
 from synapse.storage.data_stores.main.end_to_end_keys import EndToEndKeyWorkerStore
 from synapse.util.caches.stream_change_cache import StreamChangeCache
@@ -42,14 +43,22 @@ class SlavedDeviceStore(EndToEndKeyWorkerStore, DeviceWorkerStore, BaseSlavedSto
 
     def stream_positions(self):
         result = super(SlavedDeviceStore, self).stream_positions()
-        result["device_lists"] = self._device_list_id_gen.get_current_token()
+        # The user signature stream uses the same stream ID generator as the
+        # device list stream, so set them both to the device list ID
+        # generator's current token.
+        current_token = self._device_list_id_gen.get_current_token()
+        result[DeviceListsStream.NAME] = current_token
+        result[UserSignatureStream.NAME] = current_token
         return result
 
     def process_replication_rows(self, stream_name, token, rows):
-        if stream_name == "device_lists":
+        if stream_name == DeviceListsStream.NAME:
             self._device_list_id_gen.advance(token)
             for row in rows:
                 self._invalidate_caches_for_devices(token, row.user_id, row.destination)
+        elif stream_name == UserSignatureStream.NAME:
+            for row in rows:
+                self._user_signature_stream_cache.entity_has_changed(row.user_id, token)
         return super(SlavedDeviceStore, self).process_replication_rows(
             stream_name, token, rows
         )
diff --git a/synapse/replication/tcp/client.py b/synapse/replication/tcp/client.py
index a44ceb00e7..fead78388c 100644
--- a/synapse/replication/tcp/client.py
+++ b/synapse/replication/tcp/client.py
@@ -16,10 +16,17 @@
 """
 
 import logging
+from typing import Dict
 
 from twisted.internet import defer
 from twisted.internet.protocol import ReconnectingClientFactory
 
+from synapse.replication.slave.storage._base import BaseSlavedStore
+from synapse.replication.tcp.protocol import (
+    AbstractReplicationClientHandler,
+    ClientReplicationStreamProtocol,
+)
+
 from .commands import (
     FederationAckCommand,
     InvalidateCacheCommand,
@@ -27,7 +34,6 @@ from .commands import (
     UserIpCommand,
     UserSyncCommand,
 )
-from .protocol import ClientReplicationStreamProtocol
 
 logger = logging.getLogger(__name__)
 
@@ -42,7 +48,7 @@ class ReplicationClientFactory(ReconnectingClientFactory):
 
     maxDelay = 30  # Try at least once every N seconds
 
-    def __init__(self, hs, client_name, handler):
+    def __init__(self, hs, client_name, handler: AbstractReplicationClientHandler):
         self.client_name = client_name
         self.handler = handler
         self.server_name = hs.config.server_name
@@ -68,13 +74,13 @@ class ReplicationClientFactory(ReconnectingClientFactory):
         ReconnectingClientFactory.clientConnectionFailed(self, connector, reason)
 
 
-class ReplicationClientHandler(object):
+class ReplicationClientHandler(AbstractReplicationClientHandler):
     """A base handler that can be passed to the ReplicationClientFactory.
 
     By default proxies incoming replication data to the SlaveStore.
     """
 
-    def __init__(self, store):
+    def __init__(self, store: BaseSlavedStore):
         self.store = store
 
         # The current connection. None if we are currently (re)connecting
@@ -138,11 +144,13 @@ class ReplicationClientHandler(object):
         if d:
             d.callback(data)
 
-    def get_streams_to_replicate(self):
+    def get_streams_to_replicate(self) -> Dict[str, int]:
         """Called when a new connection has been established and we need to
         subscribe to streams.
 
-        Returns a dictionary of stream name to token.
+        Returns:
+            map from stream name to the most recent update we have for
+            that stream (ie, the point we want to start replicating from)
         """
         args = self.store.stream_positions()
         user_account_data = args.pop("user_account_data", None)
@@ -168,7 +176,7 @@ class ReplicationClientHandler(object):
         if self.connection:
             self.connection.send_command(cmd)
         else:
-            logger.warn("Queuing command as not connected: %r", cmd.NAME)
+            logger.warning("Queuing command as not connected: %r", cmd.NAME)
             self.pending_commands.append(cmd)
 
     def send_federation_ack(self, token):
diff --git a/synapse/replication/tcp/protocol.py b/synapse/replication/tcp/protocol.py
index 5ffdf2675d..afaf002fe6 100644
--- a/synapse/replication/tcp/protocol.py
+++ b/synapse/replication/tcp/protocol.py
@@ -48,7 +48,7 @@ indicate which side is sending, these are *not* included on the wire::
     > ERROR server stopping
     * connection closed by server *
 """
-
+import abc
 import fcntl
 import logging
 import struct
@@ -65,6 +65,7 @@ from twisted.python.failure import Failure
 from synapse.logging.context import make_deferred_yieldable, run_in_background
 from synapse.metrics import LaterGauge
 from synapse.metrics.background_process_metrics import run_as_background_process
+from synapse.util import Clock
 from synapse.util.stringutils import random_string
 
 from .commands import (
@@ -249,7 +250,7 @@ class BaseReplicationStreamProtocol(LineOnlyReceiver):
         return handler(cmd)
 
     def close(self):
-        logger.warn("[%s] Closing connection", self.id())
+        logger.warning("[%s] Closing connection", self.id())
         self.time_we_closed = self.clock.time_msec()
         self.transport.loseConnection()
         self.on_connection_closed()
@@ -558,11 +559,80 @@ class ServerReplicationStreamProtocol(BaseReplicationStreamProtocol):
         self.streamer.lost_connection(self)
 
 
+class AbstractReplicationClientHandler(metaclass=abc.ABCMeta):
+    """
+    The interface for the handler that should be passed to
+    ClientReplicationStreamProtocol
+    """
+
+    @abc.abstractmethod
+    def on_rdata(self, stream_name, token, rows):
+        """Called to handle a batch of replication data with a given stream token.
+
+        Args:
+            stream_name (str): name of the replication stream for this batch of rows
+            token (int): stream token for this batch of rows
+            rows (list): a list of Stream.ROW_TYPE objects as returned by
+                Stream.parse_row.
+
+        Returns:
+            Deferred|None
+        """
+        raise NotImplementedError()
+
+    @abc.abstractmethod
+    def on_position(self, stream_name, token):
+        """Called when we get new position data."""
+        raise NotImplementedError()
+
+    @abc.abstractmethod
+    def on_sync(self, data):
+        """Called when get a new SYNC command."""
+        raise NotImplementedError()
+
+    @abc.abstractmethod
+    def get_streams_to_replicate(self):
+        """Called when a new connection has been established and we need to
+        subscribe to streams.
+
+        Returns:
+            map from stream name to the most recent update we have for
+            that stream (ie, the point we want to start replicating from)
+        """
+        raise NotImplementedError()
+
+    @abc.abstractmethod
+    def get_currently_syncing_users(self):
+        """Get the list of currently syncing users (if any). This is called
+        when a connection has been established and we need to send the
+        currently syncing users."""
+        raise NotImplementedError()
+
+    @abc.abstractmethod
+    def update_connection(self, connection):
+        """Called when a connection has been established (or lost with None).
+        """
+        raise NotImplementedError()
+
+    @abc.abstractmethod
+    def finished_connecting(self):
+        """Called when we have successfully subscribed and caught up to all
+        streams we're interested in.
+        """
+        raise NotImplementedError()
+
+
 class ClientReplicationStreamProtocol(BaseReplicationStreamProtocol):
     VALID_INBOUND_COMMANDS = VALID_SERVER_COMMANDS
     VALID_OUTBOUND_COMMANDS = VALID_CLIENT_COMMANDS
 
-    def __init__(self, client_name, server_name, clock, handler):
+    def __init__(
+        self,
+        client_name: str,
+        server_name: str,
+        clock: Clock,
+        handler: AbstractReplicationClientHandler,
+    ):
         BaseReplicationStreamProtocol.__init__(self, clock)
 
         self.client_name = client_name
diff --git a/synapse/replication/tcp/streams/__init__.py b/synapse/replication/tcp/streams/__init__.py
index 634f636dc9..5f52264e84 100644
--- a/synapse/replication/tcp/streams/__init__.py
+++ b/synapse/replication/tcp/streams/__init__.py
@@ -45,5 +45,6 @@ STREAMS_MAP = {
         _base.TagAccountDataStream,
         _base.AccountDataStream,
         _base.GroupServerStream,
+        _base.UserSignatureStream,
     )
 }
diff --git a/synapse/replication/tcp/streams/_base.py b/synapse/replication/tcp/streams/_base.py
index f03111c259..9e45429d49 100644
--- a/synapse/replication/tcp/streams/_base.py
+++ b/synapse/replication/tcp/streams/_base.py
@@ -95,6 +95,7 @@ GroupsStreamRow = namedtuple(
     "GroupsStreamRow",
     ("group_id", "user_id", "type", "content"),  # str  # str  # str  # dict
 )
+UserSignatureStreamRow = namedtuple("UserSignatureStreamRow", ("user_id"))  # str
 
 
 class Stream(object):
@@ -438,3 +439,20 @@ class GroupServerStream(Stream):
         self.update_function = store.get_all_groups_changes
 
         super(GroupServerStream, self).__init__(hs)
+
+
+class UserSignatureStream(Stream):
+    """A user has signed their own device with their user-signing key
+    """
+
+    NAME = "user_signature"
+    _LIMITED = False
+    ROW_TYPE = UserSignatureStreamRow
+
+    def __init__(self, hs):
+        store = hs.get_datastore()
+
+        self.current_token = store.get_device_stream_token
+        self.update_function = store.get_all_user_signature_changes_for_remotes
+
+        super(UserSignatureStream, self).__init__(hs)
diff --git a/synapse/rest/admin/__init__.py b/synapse/rest/admin/__init__.py
index 939418ee2b..5c2a2eb593 100644
--- a/synapse/rest/admin/__init__.py
+++ b/synapse/rest/admin/__init__.py
@@ -286,7 +286,7 @@ class PurgeHistoryRestServlet(RestServlet):
                 room_id, stream_ordering
             )
             if not r:
-                logger.warn(
+                logger.warning(
                     "[purge] purging events not possible: No event found "
                     "(received_ts %i => stream_ordering %i)",
                     ts,
diff --git a/synapse/rest/client/v1/login.py b/synapse/rest/client/v1/login.py
index 8414af08cb..24a0ce74f2 100644
--- a/synapse/rest/client/v1/login.py
+++ b/synapse/rest/client/v1/login.py
@@ -203,10 +203,11 @@ class LoginRestServlet(RestServlet):
                 address = address.lower()
 
             # Check for login providers that support 3pid login types
-            canonical_user_id, callback_3pid = (
-                yield self.auth_handler.check_password_provider_3pid(
-                    medium, address, login_submission["password"]
-                )
+            (
+                canonical_user_id,
+                callback_3pid,
+            ) = yield self.auth_handler.check_password_provider_3pid(
+                medium, address, login_submission["password"]
             )
             if canonical_user_id:
                 # Authentication through password provider and 3pid succeeded
@@ -221,7 +222,7 @@ class LoginRestServlet(RestServlet):
                 medium, address
             )
             if not user_id:
-                logger.warn(
+                logger.warning(
                     "unknown 3pid identifier medium %s, address %r", medium, address
                 )
                 raise LoginError(403, "", errcode=Codes.FORBIDDEN)
@@ -280,8 +281,8 @@ class LoginRestServlet(RestServlet):
     def do_token_login(self, login_submission):
         token = login_submission["token"]
         auth_handler = self.auth_handler
-        user_id = (
-            yield auth_handler.validate_short_term_login_token_and_get_user_id(token)
+        user_id = yield auth_handler.validate_short_term_login_token_and_get_user_id(
+            token
         )
 
         result = yield self._register_device_with_callback(user_id, login_submission)
@@ -380,7 +381,7 @@ class CasTicketServlet(RestServlet):
         self.cas_displayname_attribute = hs.config.cas_displayname_attribute
         self.cas_required_attributes = hs.config.cas_required_attributes
         self._sso_auth_handler = SSOAuthHandler(hs)
-        self._http_client = hs.get_simple_http_client()
+        self._http_client = hs.get_proxied_http_client()
 
     @defer.inlineCallbacks
     def on_GET(self, request):
diff --git a/synapse/rest/client/v1/room.py b/synapse/rest/client/v1/room.py
index 9c1d41421c..86bbcc0eea 100644
--- a/synapse/rest/client/v1/room.py
+++ b/synapse/rest/client/v1/room.py
@@ -21,8 +21,6 @@ from six.moves.urllib import parse as urlparse
 
 from canonicaljson import json
 
-from twisted.internet import defer
-
 from synapse.api.constants import EventTypes, Membership
 from synapse.api.errors import (
     AuthError,
@@ -85,11 +83,10 @@ class RoomCreateRestServlet(TransactionRestServlet):
         set_tag("txn_id", txn_id)
         return self.txns.fetch_or_execute_request(request, self.on_POST, request)
 
-    @defer.inlineCallbacks
-    def on_POST(self, request):
-        requester = yield self.auth.get_user_by_req(request)
+    async def on_POST(self, request):
+        requester = await self.auth.get_user_by_req(request)
 
-        info = yield self._room_creation_handler.create_room(
+        info = await self._room_creation_handler.create_room(
             requester, self.get_room_config(request)
         )
 
@@ -154,15 +151,14 @@ class RoomStateEventRestServlet(TransactionRestServlet):
     def on_PUT_no_state_key(self, request, room_id, event_type):
         return self.on_PUT(request, room_id, event_type, "")
 
-    @defer.inlineCallbacks
-    def on_GET(self, request, room_id, event_type, state_key):
-        requester = yield self.auth.get_user_by_req(request, allow_guest=True)
+    async def on_GET(self, request, room_id, event_type, state_key):
+        requester = await self.auth.get_user_by_req(request, allow_guest=True)
         format = parse_string(
             request, "format", default="content", allowed_values=["content", "event"]
         )
 
         msg_handler = self.message_handler
-        data = yield msg_handler.get_room_data(
+        data = await msg_handler.get_room_data(
             user_id=requester.user.to_string(),
             room_id=room_id,
             event_type=event_type,
@@ -179,9 +175,8 @@ class RoomStateEventRestServlet(TransactionRestServlet):
         elif format == "content":
             return 200, data.get_dict()["content"]
 
-    @defer.inlineCallbacks
-    def on_PUT(self, request, room_id, event_type, state_key, txn_id=None):
-        requester = yield self.auth.get_user_by_req(request)
+    async def on_PUT(self, request, room_id, event_type, state_key, txn_id=None):
+        requester = await self.auth.get_user_by_req(request)
 
         if txn_id:
             set_tag("txn_id", txn_id)
@@ -200,7 +195,7 @@ class RoomStateEventRestServlet(TransactionRestServlet):
 
         if event_type == EventTypes.Member:
             membership = content.get("membership", None)
-            event = yield self.room_member_handler.update_membership(
+            event = await self.room_member_handler.update_membership(
                 requester,
                 target=UserID.from_string(state_key),
                 room_id=room_id,
@@ -208,7 +203,7 @@ class RoomStateEventRestServlet(TransactionRestServlet):
                 content=content,
             )
         else:
-            event = yield self.event_creation_handler.create_and_send_nonmember_event(
+            event = await self.event_creation_handler.create_and_send_nonmember_event(
                 requester, event_dict, txn_id=txn_id
             )
 
@@ -231,9 +226,8 @@ class RoomSendEventRestServlet(TransactionRestServlet):
         PATTERNS = "/rooms/(?P<room_id>[^/]*)/send/(?P<event_type>[^/]*)"
         register_txn_path(self, PATTERNS, http_server, with_get=True)
 
-    @defer.inlineCallbacks
-    def on_POST(self, request, room_id, event_type, txn_id=None):
-        requester = yield self.auth.get_user_by_req(request, allow_guest=True)
+    async def on_POST(self, request, room_id, event_type, txn_id=None):
+        requester = await self.auth.get_user_by_req(request, allow_guest=True)
         content = parse_json_object_from_request(request)
 
         event_dict = {
@@ -246,7 +240,7 @@ class RoomSendEventRestServlet(TransactionRestServlet):
         if b"ts" in request.args and requester.app_service:
             event_dict["origin_server_ts"] = parse_integer(request, "ts", 0)
 
-        event = yield self.event_creation_handler.create_and_send_nonmember_event(
+        event = await self.event_creation_handler.create_and_send_nonmember_event(
             requester, event_dict, txn_id=txn_id
         )
 
@@ -276,9 +270,8 @@ class JoinRoomAliasServlet(TransactionRestServlet):
         PATTERNS = "/join/(?P<room_identifier>[^/]*)"
         register_txn_path(self, PATTERNS, http_server)
 
-    @defer.inlineCallbacks
-    def on_POST(self, request, room_identifier, txn_id=None):
-        requester = yield self.auth.get_user_by_req(request, allow_guest=True)
+    async def on_POST(self, request, room_identifier, txn_id=None):
+        requester = await self.auth.get_user_by_req(request, allow_guest=True)
 
         try:
             content = parse_json_object_from_request(request)
@@ -298,14 +291,14 @@ class JoinRoomAliasServlet(TransactionRestServlet):
         elif RoomAlias.is_valid(room_identifier):
             handler = self.room_member_handler
             room_alias = RoomAlias.from_string(room_identifier)
-            room_id, remote_room_hosts = yield handler.lookup_room_alias(room_alias)
+            room_id, remote_room_hosts = await handler.lookup_room_alias(room_alias)
             room_id = room_id.to_string()
         else:
             raise SynapseError(
                 400, "%s was not legal room ID or room alias" % (room_identifier,)
             )
 
-        yield self.room_member_handler.update_membership(
+        await self.room_member_handler.update_membership(
             requester=requester,
             target=requester.user,
             room_id=room_id,
@@ -335,12 +328,11 @@ class PublicRoomListRestServlet(TransactionRestServlet):
         self.hs = hs
         self.auth = hs.get_auth()
 
-    @defer.inlineCallbacks
-    def on_GET(self, request):
+    async def on_GET(self, request):
         server = parse_string(request, "server", default=None)
 
         try:
-            yield self.auth.get_user_by_req(request, allow_guest=True)
+            await self.auth.get_user_by_req(request, allow_guest=True)
         except InvalidClientCredentialsError as e:
             # Option to allow servers to require auth when accessing
             # /publicRooms via CS API. This is especially helpful in private
@@ -367,19 +359,18 @@ class PublicRoomListRestServlet(TransactionRestServlet):
 
         handler = self.hs.get_room_list_handler()
         if server:
-            data = yield handler.get_remote_public_room_list(
+            data = await handler.get_remote_public_room_list(
                 server, limit=limit, since_token=since_token
             )
         else:
-            data = yield handler.get_local_public_room_list(
+            data = await handler.get_local_public_room_list(
                 limit=limit, since_token=since_token
             )
 
         return 200, data
 
-    @defer.inlineCallbacks
-    def on_POST(self, request):
-        yield self.auth.get_user_by_req(request, allow_guest=True)
+    async def on_POST(self, request):
+        await self.auth.get_user_by_req(request, allow_guest=True)
 
         server = parse_string(request, "server", default=None)
         content = parse_json_object_from_request(request)
@@ -408,7 +399,7 @@ class PublicRoomListRestServlet(TransactionRestServlet):
 
         handler = self.hs.get_room_list_handler()
         if server:
-            data = yield handler.get_remote_public_room_list(
+            data = await handler.get_remote_public_room_list(
                 server,
                 limit=limit,
                 since_token=since_token,
@@ -417,7 +408,7 @@ class PublicRoomListRestServlet(TransactionRestServlet):
                 third_party_instance_id=third_party_instance_id,
             )
         else:
-            data = yield handler.get_local_public_room_list(
+            data = await handler.get_local_public_room_list(
                 limit=limit,
                 since_token=since_token,
                 search_filter=search_filter,
@@ -436,10 +427,9 @@ class RoomMemberListRestServlet(RestServlet):
         self.message_handler = hs.get_message_handler()
         self.auth = hs.get_auth()
 
-    @defer.inlineCallbacks
-    def on_GET(self, request, room_id):
+    async def on_GET(self, request, room_id):
         # TODO support Pagination stream API (limit/tokens)
-        requester = yield self.auth.get_user_by_req(request)
+        requester = await self.auth.get_user_by_req(request)
         handler = self.message_handler
 
         # request the state as of a given event, as identified by a stream token,
@@ -459,7 +449,7 @@ class RoomMemberListRestServlet(RestServlet):
         membership = parse_string(request, "membership")
         not_membership = parse_string(request, "not_membership")
 
-        events = yield handler.get_state_events(
+        events = await handler.get_state_events(
             room_id=room_id,
             user_id=requester.user.to_string(),
             at_token=at_token,
@@ -488,11 +478,10 @@ class JoinedRoomMemberListRestServlet(RestServlet):
         self.message_handler = hs.get_message_handler()
         self.auth = hs.get_auth()
 
-    @defer.inlineCallbacks
-    def on_GET(self, request, room_id):
-        requester = yield self.auth.get_user_by_req(request)
+    async def on_GET(self, request, room_id):
+        requester = await self.auth.get_user_by_req(request)
 
-        users_with_profile = yield self.message_handler.get_joined_members(
+        users_with_profile = await self.message_handler.get_joined_members(
             requester, room_id
         )
 
@@ -508,9 +497,8 @@ class RoomMessageListRestServlet(RestServlet):
         self.pagination_handler = hs.get_pagination_handler()
         self.auth = hs.get_auth()
 
-    @defer.inlineCallbacks
-    def on_GET(self, request, room_id):
-        requester = yield self.auth.get_user_by_req(request, allow_guest=True)
+    async def on_GET(self, request, room_id):
+        requester = await self.auth.get_user_by_req(request, allow_guest=True)
         pagination_config = PaginationConfig.from_request(request, default_limit=10)
         as_client_event = b"raw" not in request.args
         filter_bytes = parse_string(request, b"filter", encoding=None)
@@ -521,7 +509,7 @@ class RoomMessageListRestServlet(RestServlet):
                 as_client_event = False
         else:
             event_filter = None
-        msgs = yield self.pagination_handler.get_messages(
+        msgs = await self.pagination_handler.get_messages(
             room_id=room_id,
             requester=requester,
             pagin_config=pagination_config,
@@ -541,11 +529,10 @@ class RoomStateRestServlet(RestServlet):
         self.message_handler = hs.get_message_handler()
         self.auth = hs.get_auth()
 
-    @defer.inlineCallbacks
-    def on_GET(self, request, room_id):
-        requester = yield self.auth.get_user_by_req(request, allow_guest=True)
+    async def on_GET(self, request, room_id):
+        requester = await self.auth.get_user_by_req(request, allow_guest=True)
         # Get all the current state for this room
-        events = yield self.message_handler.get_state_events(
+        events = await self.message_handler.get_state_events(
             room_id=room_id,
             user_id=requester.user.to_string(),
             is_guest=requester.is_guest,
@@ -562,11 +549,10 @@ class RoomInitialSyncRestServlet(RestServlet):
         self.initial_sync_handler = hs.get_initial_sync_handler()
         self.auth = hs.get_auth()
 
-    @defer.inlineCallbacks
-    def on_GET(self, request, room_id):
-        requester = yield self.auth.get_user_by_req(request, allow_guest=True)
+    async def on_GET(self, request, room_id):
+        requester = await self.auth.get_user_by_req(request, allow_guest=True)
         pagination_config = PaginationConfig.from_request(request)
-        content = yield self.initial_sync_handler.room_initial_sync(
+        content = await self.initial_sync_handler.room_initial_sync(
             room_id=room_id, requester=requester, pagin_config=pagination_config
         )
         return 200, content
@@ -584,11 +570,10 @@ class RoomEventServlet(RestServlet):
         self._event_serializer = hs.get_event_client_serializer()
         self.auth = hs.get_auth()
 
-    @defer.inlineCallbacks
-    def on_GET(self, request, room_id, event_id):
-        requester = yield self.auth.get_user_by_req(request, allow_guest=True)
+    async def on_GET(self, request, room_id, event_id):
+        requester = await self.auth.get_user_by_req(request, allow_guest=True)
         try:
-            event = yield self.event_handler.get_event(
+            event = await self.event_handler.get_event(
                 requester.user, room_id, event_id
             )
         except AuthError:
@@ -599,7 +584,7 @@ class RoomEventServlet(RestServlet):
 
         time_now = self.clock.time_msec()
         if event:
-            event = yield self._event_serializer.serialize_event(event, time_now)
+            event = await self._event_serializer.serialize_event(event, time_now)
             return 200, event
 
         return SynapseError(404, "Event not found.", errcode=Codes.NOT_FOUND)
@@ -617,9 +602,8 @@ class RoomEventContextServlet(RestServlet):
         self._event_serializer = hs.get_event_client_serializer()
         self.auth = hs.get_auth()
 
-    @defer.inlineCallbacks
-    def on_GET(self, request, room_id, event_id):
-        requester = yield self.auth.get_user_by_req(request, allow_guest=True)
+    async def on_GET(self, request, room_id, event_id):
+        requester = await self.auth.get_user_by_req(request, allow_guest=True)
 
         limit = parse_integer(request, "limit", default=10)
 
@@ -631,7 +615,7 @@ class RoomEventContextServlet(RestServlet):
         else:
             event_filter = None
 
-        results = yield self.room_context_handler.get_event_context(
+        results = await self.room_context_handler.get_event_context(
             requester.user, room_id, event_id, limit, event_filter
         )
 
@@ -639,16 +623,16 @@ class RoomEventContextServlet(RestServlet):
             raise SynapseError(404, "Event not found.", errcode=Codes.NOT_FOUND)
 
         time_now = self.clock.time_msec()
-        results["events_before"] = yield self._event_serializer.serialize_events(
+        results["events_before"] = await self._event_serializer.serialize_events(
             results["events_before"], time_now
         )
-        results["event"] = yield self._event_serializer.serialize_event(
+        results["event"] = await self._event_serializer.serialize_event(
             results["event"], time_now
         )
-        results["events_after"] = yield self._event_serializer.serialize_events(
+        results["events_after"] = await self._event_serializer.serialize_events(
             results["events_after"], time_now
         )
-        results["state"] = yield self._event_serializer.serialize_events(
+        results["state"] = await self._event_serializer.serialize_events(
             results["state"], time_now
         )
 
@@ -665,11 +649,10 @@ class RoomForgetRestServlet(TransactionRestServlet):
         PATTERNS = "/rooms/(?P<room_id>[^/]*)/forget"
         register_txn_path(self, PATTERNS, http_server)
 
-    @defer.inlineCallbacks
-    def on_POST(self, request, room_id, txn_id=None):
-        requester = yield self.auth.get_user_by_req(request, allow_guest=False)
+    async def on_POST(self, request, room_id, txn_id=None):
+        requester = await self.auth.get_user_by_req(request, allow_guest=False)
 
-        yield self.room_member_handler.forget(user=requester.user, room_id=room_id)
+        await self.room_member_handler.forget(user=requester.user, room_id=room_id)
 
         return 200, {}
 
@@ -696,9 +679,8 @@ class RoomMembershipRestServlet(TransactionRestServlet):
         )
         register_txn_path(self, PATTERNS, http_server)
 
-    @defer.inlineCallbacks
-    def on_POST(self, request, room_id, membership_action, txn_id=None):
-        requester = yield self.auth.get_user_by_req(request, allow_guest=True)
+    async def on_POST(self, request, room_id, membership_action, txn_id=None):
+        requester = await self.auth.get_user_by_req(request, allow_guest=True)
 
         if requester.is_guest and membership_action not in {
             Membership.JOIN,
@@ -714,7 +696,7 @@ class RoomMembershipRestServlet(TransactionRestServlet):
             content = {}
 
         if membership_action == "invite" and self._has_3pid_invite_keys(content):
-            yield self.room_member_handler.do_3pid_invite(
+            await self.room_member_handler.do_3pid_invite(
                 room_id,
                 requester.user,
                 content["medium"],
@@ -735,7 +717,7 @@ class RoomMembershipRestServlet(TransactionRestServlet):
         if "reason" in content and membership_action in ["kick", "ban"]:
             event_content = {"reason": content["reason"]}
 
-        yield self.room_member_handler.update_membership(
+        await self.room_member_handler.update_membership(
             requester=requester,
             target=target,
             room_id=room_id,
@@ -777,12 +759,11 @@ class RoomRedactEventRestServlet(TransactionRestServlet):
         PATTERNS = "/rooms/(?P<room_id>[^/]*)/redact/(?P<event_id>[^/]*)"
         register_txn_path(self, PATTERNS, http_server)
 
-    @defer.inlineCallbacks
-    def on_POST(self, request, room_id, event_id, txn_id=None):
-        requester = yield self.auth.get_user_by_req(request)
+    async def on_POST(self, request, room_id, event_id, txn_id=None):
+        requester = await self.auth.get_user_by_req(request)
         content = parse_json_object_from_request(request)
 
-        event = yield self.event_creation_handler.create_and_send_nonmember_event(
+        event = await self.event_creation_handler.create_and_send_nonmember_event(
             requester,
             {
                 "type": EventTypes.Redaction,
@@ -816,29 +797,28 @@ class RoomTypingRestServlet(RestServlet):
         self.typing_handler = hs.get_typing_handler()
         self.auth = hs.get_auth()
 
-    @defer.inlineCallbacks
-    def on_PUT(self, request, room_id, user_id):
-        requester = yield self.auth.get_user_by_req(request)
+    async def on_PUT(self, request, room_id, user_id):
+        requester = await self.auth.get_user_by_req(request)
 
         room_id = urlparse.unquote(room_id)
         target_user = UserID.from_string(urlparse.unquote(user_id))
 
         content = parse_json_object_from_request(request)
 
-        yield self.presence_handler.bump_presence_active_time(requester.user)
+        await self.presence_handler.bump_presence_active_time(requester.user)
 
         # Limit timeout to stop people from setting silly typing timeouts.
         timeout = min(content.get("timeout", 30000), 120000)
 
         if content["typing"]:
-            yield self.typing_handler.started_typing(
+            await self.typing_handler.started_typing(
                 target_user=target_user,
                 auth_user=requester.user,
                 room_id=room_id,
                 timeout=timeout,
             )
         else:
-            yield self.typing_handler.stopped_typing(
+            await self.typing_handler.stopped_typing(
                 target_user=target_user, auth_user=requester.user, room_id=room_id
             )
 
@@ -853,14 +833,13 @@ class SearchRestServlet(RestServlet):
         self.handlers = hs.get_handlers()
         self.auth = hs.get_auth()
 
-    @defer.inlineCallbacks
-    def on_POST(self, request):
-        requester = yield self.auth.get_user_by_req(request)
+    async def on_POST(self, request):
+        requester = await self.auth.get_user_by_req(request)
 
         content = parse_json_object_from_request(request)
 
         batch = parse_string(request, "next_batch")
-        results = yield self.handlers.search_handler.search(
+        results = await self.handlers.search_handler.search(
             requester.user, content, batch
         )
 
@@ -875,11 +854,10 @@ class JoinedRoomsRestServlet(RestServlet):
         self.store = hs.get_datastore()
         self.auth = hs.get_auth()
 
-    @defer.inlineCallbacks
-    def on_GET(self, request):
-        requester = yield self.auth.get_user_by_req(request, allow_guest=True)
+    async def on_GET(self, request):
+        requester = await self.auth.get_user_by_req(request, allow_guest=True)
 
-        room_ids = yield self.store.get_rooms_for_user(requester.user.to_string())
+        room_ids = await self.store.get_rooms_for_user(requester.user.to_string())
         return 200, {"joined_rooms": list(room_ids)}
 
 
diff --git a/synapse/rest/client/v2_alpha/account.py b/synapse/rest/client/v2_alpha/account.py
index 80cf7126a0..f26eae794c 100644
--- a/synapse/rest/client/v2_alpha/account.py
+++ b/synapse/rest/client/v2_alpha/account.py
@@ -71,7 +71,7 @@ class EmailPasswordRequestTokenRestServlet(RestServlet):
     def on_POST(self, request):
         if self.config.threepid_behaviour_email == ThreepidBehaviour.OFF:
             if self.config.local_threepid_handling_disabled_due_to_email_config:
-                logger.warn(
+                logger.warning(
                     "User password resets have been disabled due to lack of email config"
                 )
             raise SynapseError(
@@ -148,7 +148,7 @@ class PasswordResetSubmitTokenServlet(RestServlet):
         self.clock = hs.get_clock()
         self.store = hs.get_datastore()
         if self.config.threepid_behaviour_email == ThreepidBehaviour.LOCAL:
-            self.failure_email_template, = load_jinja2_templates(
+            (self.failure_email_template,) = load_jinja2_templates(
                 self.config.email_template_dir,
                 [self.config.email_password_reset_template_failure_html],
             )
@@ -162,7 +162,7 @@ class PasswordResetSubmitTokenServlet(RestServlet):
             )
         if self.config.threepid_behaviour_email == ThreepidBehaviour.OFF:
             if self.config.local_threepid_handling_disabled_due_to_email_config:
-                logger.warn(
+                logger.warning(
                     "Password reset emails have been disabled due to lack of an email config"
                 )
             raise SynapseError(
@@ -183,7 +183,7 @@ class PasswordResetSubmitTokenServlet(RestServlet):
             # Perform a 302 redirect if next_link is set
             if next_link:
                 if next_link.startswith("file:///"):
-                    logger.warn(
+                    logger.warning(
                         "Not redirecting to next_link as it is a local file: address"
                     )
                 else:
@@ -350,7 +350,7 @@ class EmailThreepidRequestTokenRestServlet(RestServlet):
     def on_POST(self, request):
         if self.config.threepid_behaviour_email == ThreepidBehaviour.OFF:
             if self.config.local_threepid_handling_disabled_due_to_email_config:
-                logger.warn(
+                logger.warning(
                     "Adding emails have been disabled due to lack of an email config"
                 )
             raise SynapseError(
@@ -441,7 +441,7 @@ class MsisdnThreepidRequestTokenRestServlet(RestServlet):
             raise SynapseError(400, "MSISDN is already in use", Codes.THREEPID_IN_USE)
 
         if not self.hs.config.account_threepid_delegate_msisdn:
-            logger.warn(
+            logger.warning(
                 "No upstream msisdn account_threepid_delegate configured on the server to "
                 "handle this request"
             )
@@ -479,7 +479,7 @@ class AddThreepidEmailSubmitTokenServlet(RestServlet):
         self.clock = hs.get_clock()
         self.store = hs.get_datastore()
         if self.config.threepid_behaviour_email == ThreepidBehaviour.LOCAL:
-            self.failure_email_template, = load_jinja2_templates(
+            (self.failure_email_template,) = load_jinja2_templates(
                 self.config.email_template_dir,
                 [self.config.email_add_threepid_template_failure_html],
             )
@@ -488,7 +488,7 @@ class AddThreepidEmailSubmitTokenServlet(RestServlet):
     def on_GET(self, request):
         if self.config.threepid_behaviour_email == ThreepidBehaviour.OFF:
             if self.config.local_threepid_handling_disabled_due_to_email_config:
-                logger.warn(
+                logger.warning(
                     "Adding emails have been disabled due to lack of an email config"
                 )
             raise SynapseError(
@@ -515,7 +515,7 @@ class AddThreepidEmailSubmitTokenServlet(RestServlet):
             # Perform a 302 redirect if next_link is set
             if next_link:
                 if next_link.startswith("file:///"):
-                    logger.warn(
+                    logger.warning(
                         "Not redirecting to next_link as it is a local file: address"
                     )
                 else:
diff --git a/synapse/rest/client/v2_alpha/read_marker.py b/synapse/rest/client/v2_alpha/read_marker.py
index b3bf8567e1..67cbc37312 100644
--- a/synapse/rest/client/v2_alpha/read_marker.py
+++ b/synapse/rest/client/v2_alpha/read_marker.py
@@ -15,8 +15,6 @@
 
 import logging
 
-from twisted.internet import defer
-
 from synapse.http.servlet import RestServlet, parse_json_object_from_request
 
 from ._base import client_patterns
@@ -34,17 +32,16 @@ class ReadMarkerRestServlet(RestServlet):
         self.read_marker_handler = hs.get_read_marker_handler()
         self.presence_handler = hs.get_presence_handler()
 
-    @defer.inlineCallbacks
-    def on_POST(self, request, room_id):
-        requester = yield self.auth.get_user_by_req(request)
+    async def on_POST(self, request, room_id):
+        requester = await self.auth.get_user_by_req(request)
 
-        yield self.presence_handler.bump_presence_active_time(requester.user)
+        await self.presence_handler.bump_presence_active_time(requester.user)
 
         body = parse_json_object_from_request(request)
 
         read_event_id = body.get("m.read", None)
         if read_event_id:
-            yield self.receipts_handler.received_client_receipt(
+            await self.receipts_handler.received_client_receipt(
                 room_id,
                 "m.read",
                 user_id=requester.user.to_string(),
@@ -53,7 +50,7 @@ class ReadMarkerRestServlet(RestServlet):
 
         read_marker_event_id = body.get("m.fully_read", None)
         if read_marker_event_id:
-            yield self.read_marker_handler.received_client_read_marker(
+            await self.read_marker_handler.received_client_read_marker(
                 room_id,
                 user_id=requester.user.to_string(),
                 event_id=read_marker_event_id,
diff --git a/synapse/rest/client/v2_alpha/receipts.py b/synapse/rest/client/v2_alpha/receipts.py
index 0dab03d227..92555bd4a9 100644
--- a/synapse/rest/client/v2_alpha/receipts.py
+++ b/synapse/rest/client/v2_alpha/receipts.py
@@ -15,8 +15,6 @@
 
 import logging
 
-from twisted.internet import defer
-
 from synapse.api.errors import SynapseError
 from synapse.http.servlet import RestServlet
 
@@ -39,16 +37,15 @@ class ReceiptRestServlet(RestServlet):
         self.receipts_handler = hs.get_receipts_handler()
         self.presence_handler = hs.get_presence_handler()
 
-    @defer.inlineCallbacks
-    def on_POST(self, request, room_id, receipt_type, event_id):
-        requester = yield self.auth.get_user_by_req(request)
+    async def on_POST(self, request, room_id, receipt_type, event_id):
+        requester = await self.auth.get_user_by_req(request)
 
         if receipt_type != "m.read":
             raise SynapseError(400, "Receipt type must be 'm.read'")
 
-        yield self.presence_handler.bump_presence_active_time(requester.user)
+        await self.presence_handler.bump_presence_active_time(requester.user)
 
-        yield self.receipts_handler.received_client_receipt(
+        await self.receipts_handler.received_client_receipt(
             room_id, receipt_type, user_id=requester.user.to_string(), event_id=event_id
         )
 
diff --git a/synapse/rest/client/v2_alpha/register.py b/synapse/rest/client/v2_alpha/register.py
index 4f24a124a6..91db923814 100644
--- a/synapse/rest/client/v2_alpha/register.py
+++ b/synapse/rest/client/v2_alpha/register.py
@@ -106,7 +106,7 @@ class EmailRegisterRequestTokenRestServlet(RestServlet):
     def on_POST(self, request):
         if self.hs.config.threepid_behaviour_email == ThreepidBehaviour.OFF:
             if self.hs.config.local_threepid_handling_disabled_due_to_email_config:
-                logger.warn(
+                logger.warning(
                     "Email registration has been disabled due to lack of email config"
                 )
             raise SynapseError(
@@ -207,7 +207,7 @@ class MsisdnRegisterRequestTokenRestServlet(RestServlet):
             )
 
         if not self.hs.config.account_threepid_delegate_msisdn:
-            logger.warn(
+            logger.warning(
                 "No upstream msisdn account_threepid_delegate configured on the server to "
                 "handle this request"
             )
@@ -247,13 +247,13 @@ class RegistrationSubmitTokenServlet(RestServlet):
         self.store = hs.get_datastore()
 
         if self.config.threepid_behaviour_email == ThreepidBehaviour.LOCAL:
-            self.failure_email_template, = load_jinja2_templates(
+            (self.failure_email_template,) = load_jinja2_templates(
                 self.config.email_template_dir,
                 [self.config.email_registration_template_failure_html],
             )
 
         if self.config.threepid_behaviour_email == ThreepidBehaviour.LOCAL:
-            self.failure_email_template, = load_jinja2_templates(
+            (self.failure_email_template,) = load_jinja2_templates(
                 self.config.email_template_dir,
                 [self.config.email_registration_template_failure_html],
             )
@@ -266,7 +266,7 @@ class RegistrationSubmitTokenServlet(RestServlet):
             )
         if self.config.threepid_behaviour_email == ThreepidBehaviour.OFF:
             if self.config.local_threepid_handling_disabled_due_to_email_config:
-                logger.warn(
+                logger.warning(
                     "User registration via email has been disabled due to lack of email config"
                 )
             raise SynapseError(
@@ -287,7 +287,7 @@ class RegistrationSubmitTokenServlet(RestServlet):
             # Perform a 302 redirect if next_link is set
             if next_link:
                 if next_link.startswith("file:///"):
-                    logger.warn(
+                    logger.warning(
                         "Not redirecting to next_link as it is a local file: address"
                     )
                 else:
@@ -480,7 +480,7 @@ class RegisterRestServlet(RestServlet):
             # a password to work around a client bug where it sent
             # the 'initial_device_display_name' param alone, wiping out
             # the original registration params
-            logger.warn("Ignoring initial_device_display_name without password")
+            logger.warning("Ignoring initial_device_display_name without password")
             del body["initial_device_display_name"]
 
         session_id = self.auth_handler.get_session_id(body)
diff --git a/synapse/rest/client/v2_alpha/sync.py b/synapse/rest/client/v2_alpha/sync.py
index a883c8adda..ccd8b17b23 100644
--- a/synapse/rest/client/v2_alpha/sync.py
+++ b/synapse/rest/client/v2_alpha/sync.py
@@ -112,9 +112,14 @@ class SyncRestServlet(RestServlet):
         full_state = parse_boolean(request, "full_state", default=False)
 
         logger.debug(
-            "/sync: user=%r, timeout=%r, since=%r,"
-            " set_presence=%r, filter_id=%r, device_id=%r"
-            % (user, timeout, since, set_presence, filter_id, device_id)
+            "/sync: user=%r, timeout=%r, since=%r, "
+            "set_presence=%r, filter_id=%r, device_id=%r",
+            user,
+            timeout,
+            since,
+            set_presence,
+            filter_id,
+            device_id,
         )
 
         request_key = (user, timeout, since, filter_id, full_state, device_id)
@@ -389,7 +394,7 @@ class SyncRestServlet(RestServlet):
             # We've had bug reports that events were coming down under the
             # wrong room.
             if event.room_id != room.room_id:
-                logger.warn(
+                logger.warning(
                     "Event %r is under room %r instead of %r",
                     event.event_id,
                     room.room_id,
diff --git a/synapse/rest/client/versions.py b/synapse/rest/client/versions.py
index 1044ae7b4e..bb30ce3f34 100644
--- a/synapse/rest/client/versions.py
+++ b/synapse/rest/client/versions.py
@@ -65,6 +65,9 @@ class VersionsRestServlet(RestServlet):
                     "m.require_identity_server": False,
                     # as per MSC2290
                     "m.separate_add_and_bind": True,
+                    # Implements support for label-based filtering as described in
+                    # MSC2326.
+                    "org.matrix.label_based_filtering": True,
                 },
             },
         )
diff --git a/synapse/rest/key/v2/remote_key_resource.py b/synapse/rest/key/v2/remote_key_resource.py
index 55580bc59e..e7fc3f0431 100644
--- a/synapse/rest/key/v2/remote_key_resource.py
+++ b/synapse/rest/key/v2/remote_key_resource.py
@@ -102,7 +102,7 @@ class RemoteKey(DirectServeResource):
     @wrap_json_request_handler
     async def _async_render_GET(self, request):
         if len(request.postpath) == 1:
-            server, = request.postpath
+            (server,) = request.postpath
             query = {server.decode("ascii"): {}}
         elif len(request.postpath) == 2:
             server, key_id = request.postpath
diff --git a/synapse/rest/media/v1/media_repository.py b/synapse/rest/media/v1/media_repository.py
index b972e152a9..bd9186fe50 100644
--- a/synapse/rest/media/v1/media_repository.py
+++ b/synapse/rest/media/v1/media_repository.py
@@ -363,7 +363,7 @@ class MediaRepository(object):
                     },
                 )
             except RequestSendFailed as e:
-                logger.warn(
+                logger.warning(
                     "Request failed fetching remote media %s/%s: %r",
                     server_name,
                     media_id,
@@ -372,7 +372,7 @@ class MediaRepository(object):
                 raise SynapseError(502, "Failed to fetch remote media")
 
             except HttpResponseException as e:
-                logger.warn(
+                logger.warning(
                     "HTTP error fetching remote media %s/%s: %s",
                     server_name,
                     media_id,
@@ -383,10 +383,12 @@ class MediaRepository(object):
                 raise SynapseError(502, "Failed to fetch remote media")
 
             except SynapseError:
-                logger.warn("Failed to fetch remote media %s/%s", server_name, media_id)
+                logger.warning(
+                    "Failed to fetch remote media %s/%s", server_name, media_id
+                )
                 raise
             except NotRetryingDestination:
-                logger.warn("Not retrying destination %r", server_name)
+                logger.warning("Not retrying destination %r", server_name)
                 raise SynapseError(502, "Failed to fetch remote media")
             except Exception:
                 logger.exception(
@@ -691,7 +693,7 @@ class MediaRepository(object):
                 try:
                     os.remove(full_path)
                 except OSError as e:
-                    logger.warn("Failed to remove file: %r", full_path)
+                    logger.warning("Failed to remove file: %r", full_path)
                     if e.errno == errno.ENOENT:
                         pass
                     else:
diff --git a/synapse/rest/media/v1/preview_url_resource.py b/synapse/rest/media/v1/preview_url_resource.py
index ec9c4619c9..15c15a12f5 100644
--- a/synapse/rest/media/v1/preview_url_resource.py
+++ b/synapse/rest/media/v1/preview_url_resource.py
@@ -77,6 +77,8 @@ class PreviewUrlResource(DirectServeResource):
             treq_args={"browser_like_redirects": True},
             ip_whitelist=hs.config.url_preview_ip_range_whitelist,
             ip_blacklist=hs.config.url_preview_ip_range_blacklist,
+            http_proxy=os.getenv("http_proxy"),
+            https_proxy=os.getenv("HTTPS_PROXY"),
         )
         self.media_repo = media_repo
         self.primary_base_path = media_repo.primary_base_path
@@ -120,8 +122,10 @@ class PreviewUrlResource(DirectServeResource):
                 pattern = entry[attrib]
                 value = getattr(url_tuple, attrib)
                 logger.debug(
-                    ("Matching attrib '%s' with value '%s' against" " pattern '%s'")
-                    % (attrib, value, pattern)
+                    "Matching attrib '%s' with value '%s' against" " pattern '%s'",
+                    attrib,
+                    value,
+                    pattern,
                 )
 
                 if value is None:
@@ -137,7 +141,7 @@ class PreviewUrlResource(DirectServeResource):
                         match = False
                         continue
             if match:
-                logger.warn("URL %s blocked by url_blacklist entry %s", url, entry)
+                logger.warning("URL %s blocked by url_blacklist entry %s", url, entry)
                 raise SynapseError(
                     403, "URL blocked by url pattern blacklist entry", Codes.UNKNOWN
                 )
@@ -189,7 +193,7 @@ class PreviewUrlResource(DirectServeResource):
 
         media_info = yield self._download_url(url, user)
 
-        logger.debug("got media_info of '%s'" % media_info)
+        logger.debug("got media_info of '%s'", media_info)
 
         if _is_media(media_info["media_type"]):
             file_id = media_info["filesystem_id"]
@@ -209,7 +213,7 @@ class PreviewUrlResource(DirectServeResource):
                 og["og:image:width"] = dims["width"]
                 og["og:image:height"] = dims["height"]
             else:
-                logger.warn("Couldn't get dims for %s" % url)
+                logger.warning("Couldn't get dims for %s" % url)
 
             # define our OG response for this media
         elif _is_html(media_info["media_type"]):
@@ -257,7 +261,7 @@ class PreviewUrlResource(DirectServeResource):
                         og["og:image:width"] = dims["width"]
                         og["og:image:height"] = dims["height"]
                     else:
-                        logger.warn("Couldn't get dims for %s" % og["og:image"])
+                        logger.warning("Couldn't get dims for %s", og["og:image"])
 
                     og["og:image"] = "mxc://%s/%s" % (
                         self.server_name,
@@ -268,7 +272,7 @@ class PreviewUrlResource(DirectServeResource):
                 else:
                     del og["og:image"]
         else:
-            logger.warn("Failed to find any OG data in %s", url)
+            logger.warning("Failed to find any OG data in %s", url)
             og = {}
 
         # filter out any stupidly long values
@@ -283,7 +287,7 @@ class PreviewUrlResource(DirectServeResource):
         for k in keys_to_remove:
             del og[k]
 
-        logger.debug("Calculated OG for %s as %s" % (url, og))
+        logger.debug("Calculated OG for %s as %s", url, og)
 
         jsonog = json.dumps(og)
 
@@ -312,7 +316,7 @@ class PreviewUrlResource(DirectServeResource):
 
         with self.media_storage.store_into_file(file_info) as (f, fname, finish):
             try:
-                logger.debug("Trying to get url '%s'" % url)
+                logger.debug("Trying to get url '%s'", url)
                 length, headers, uri, code = yield self.client.get_file(
                     url, output_stream=f, max_size=self.max_spider_size
                 )
@@ -332,7 +336,7 @@ class PreviewUrlResource(DirectServeResource):
                 )
             except Exception as e:
                 # FIXME: pass through 404s and other error messages nicely
-                logger.warn("Error downloading %s: %r", url, e)
+                logger.warning("Error downloading %s: %r", url, e)
 
                 raise SynapseError(
                     500,
@@ -413,7 +417,7 @@ class PreviewUrlResource(DirectServeResource):
             except OSError as e:
                 # If the path doesn't exist, meh
                 if e.errno != errno.ENOENT:
-                    logger.warn("Failed to remove media: %r: %s", media_id, e)
+                    logger.warning("Failed to remove media: %r: %s", media_id, e)
                     continue
 
             removed_media.append(media_id)
@@ -445,7 +449,7 @@ class PreviewUrlResource(DirectServeResource):
             except OSError as e:
                 # If the path doesn't exist, meh
                 if e.errno != errno.ENOENT:
-                    logger.warn("Failed to remove media: %r: %s", media_id, e)
+                    logger.warning("Failed to remove media: %r: %s", media_id, e)
                     continue
 
             try:
@@ -461,7 +465,7 @@ class PreviewUrlResource(DirectServeResource):
             except OSError as e:
                 # If the path doesn't exist, meh
                 if e.errno != errno.ENOENT:
-                    logger.warn("Failed to remove media: %r: %s", media_id, e)
+                    logger.warning("Failed to remove media: %r: %s", media_id, e)
                     continue
 
             removed_media.append(media_id)
diff --git a/synapse/rest/media/v1/thumbnail_resource.py b/synapse/rest/media/v1/thumbnail_resource.py
index 08329884ac..931ce79be8 100644
--- a/synapse/rest/media/v1/thumbnail_resource.py
+++ b/synapse/rest/media/v1/thumbnail_resource.py
@@ -182,7 +182,7 @@ class ThumbnailResource(DirectServeResource):
         if file_path:
             yield respond_with_file(request, desired_type, file_path)
         else:
-            logger.warn("Failed to generate thumbnail")
+            logger.warning("Failed to generate thumbnail")
             respond_404(request)
 
     @defer.inlineCallbacks
@@ -245,7 +245,7 @@ class ThumbnailResource(DirectServeResource):
         if file_path:
             yield respond_with_file(request, desired_type, file_path)
         else:
-            logger.warn("Failed to generate thumbnail")
+            logger.warning("Failed to generate thumbnail")
             respond_404(request)
 
     @defer.inlineCallbacks
diff --git a/synapse/server.py b/synapse/server.py
index 1fcc7375d3..90c3b072e8 100644
--- a/synapse/server.py
+++ b/synapse/server.py
@@ -23,6 +23,7 @@
 # Imports required for the default HomeServer() implementation
 import abc
 import logging
+import os
 
 from twisted.enterprise import adbapi
 from twisted.mail.smtp import sendmail
@@ -95,6 +96,7 @@ from synapse.server_notices.worker_server_notices_sender import (
     WorkerServerNoticesSender,
 )
 from synapse.state import StateHandler, StateResolutionHandler
+from synapse.storage import DataStores, Storage
 from synapse.streams.events import EventSources
 from synapse.util import Clock
 from synapse.util.distributor import Distributor
@@ -167,6 +169,7 @@ class HomeServer(object):
         "filtering",
         "http_client_context_factory",
         "simple_http_client",
+        "proxied_http_client",
         "media_repository",
         "media_repository_resource",
         "federation_transport_client",
@@ -196,6 +199,7 @@ class HomeServer(object):
         "account_validity_handler",
         "saml_handler",
         "event_client_serializer",
+        "storage",
     ]
 
     REQUIRED_ON_MASTER_STARTUP = ["user_directory_handler", "stats_handler"]
@@ -217,6 +221,7 @@ class HomeServer(object):
         self.hostname = hostname
         self._building = {}
         self._listening_services = []
+        self.start_time = None
 
         self.clock = Clock(reactor)
         self.distributor = Distributor()
@@ -224,7 +229,7 @@ class HomeServer(object):
         self.admin_redaction_ratelimiter = Ratelimiter()
         self.registration_ratelimiter = Ratelimiter()
 
-        self.datastore = None
+        self.datastores = None
 
         # Other kwargs are explicit dependencies
         for depname in kwargs:
@@ -233,8 +238,10 @@ class HomeServer(object):
     def setup(self):
         logger.info("Setting up.")
         with self.get_db_conn() as conn:
-            self.datastore = self.DATASTORE_CLASS(conn, self)
+            datastore = self.DATASTORE_CLASS(conn, self)
+            self.datastores = DataStores(datastore, conn, self)
             conn.commit()
+        self.start_time = int(self.get_clock().time())
         logger.info("Finished setting up.")
 
     def setup_master(self):
@@ -266,7 +273,7 @@ class HomeServer(object):
         return self.clock
 
     def get_datastore(self):
-        return self.datastore
+        return self.datastores.main
 
     def get_config(self):
         return self.config
@@ -308,6 +315,13 @@ class HomeServer(object):
     def build_simple_http_client(self):
         return SimpleHttpClient(self)
 
+    def build_proxied_http_client(self):
+        return SimpleHttpClient(
+            self,
+            http_proxy=os.getenv("http_proxy"),
+            https_proxy=os.getenv("HTTPS_PROXY"),
+        )
+
     def build_room_creation_handler(self):
         return RoomCreationHandler(self)
 
@@ -537,6 +551,9 @@ class HomeServer(object):
     def build_event_client_serializer(self):
         return EventClientSerializer(self)
 
+    def build_storage(self) -> Storage:
+        return Storage(self, self.datastores)
+
     def remove_pusher(self, app_id, push_key, user_id):
         return self.get_pusherpool().remove_pusher(app_id, push_key, user_id)
 
diff --git a/synapse/server.pyi b/synapse/server.pyi
index 16f8f6b573..b5e0b57095 100644
--- a/synapse/server.pyi
+++ b/synapse/server.pyi
@@ -12,6 +12,7 @@ import synapse.handlers.message
 import synapse.handlers.room
 import synapse.handlers.room_member
 import synapse.handlers.set_password
+import synapse.http.client
 import synapse.rest.media.v1.media_repository
 import synapse.server_notices.server_notices_manager
 import synapse.server_notices.server_notices_sender
@@ -38,8 +39,16 @@ class HomeServer(object):
         pass
     def get_state_resolution_handler(self) -> synapse.state.StateResolutionHandler:
         pass
+    def get_simple_http_client(self) -> synapse.http.client.SimpleHttpClient:
+        """Fetch an HTTP client implementation which doesn't do any blacklisting
+        or support any HTTP_PROXY settings"""
+        pass
+    def get_proxied_http_client(self) -> synapse.http.client.SimpleHttpClient:
+        """Fetch an HTTP client implementation which doesn't do any blacklisting
+        but does support HTTP_PROXY settings"""
+        pass
     def get_deactivate_account_handler(
-        self
+        self,
     ) -> synapse.handlers.deactivate_account.DeactivateAccountHandler:
         pass
     def get_room_creation_handler(self) -> synapse.handlers.room.RoomCreationHandler:
@@ -47,32 +56,32 @@ class HomeServer(object):
     def get_room_member_handler(self) -> synapse.handlers.room_member.RoomMemberHandler:
         pass
     def get_event_creation_handler(
-        self
+        self,
     ) -> synapse.handlers.message.EventCreationHandler:
         pass
     def get_set_password_handler(
-        self
+        self,
     ) -> synapse.handlers.set_password.SetPasswordHandler:
         pass
     def get_federation_sender(self) -> synapse.federation.sender.FederationSender:
         pass
     def get_federation_transport_client(
-        self
+        self,
     ) -> synapse.federation.transport.client.TransportLayerClient:
         pass
     def get_media_repository_resource(
-        self
+        self,
     ) -> synapse.rest.media.v1.media_repository.MediaRepositoryResource:
         pass
     def get_media_repository(
-        self
+        self,
     ) -> synapse.rest.media.v1.media_repository.MediaRepository:
         pass
     def get_server_notices_manager(
-        self
+        self,
     ) -> synapse.server_notices.server_notices_manager.ServerNoticesManager:
         pass
     def get_server_notices_sender(
-        self
+        self,
     ) -> synapse.server_notices.server_notices_sender.ServerNoticesSender:
         pass
diff --git a/synapse/server_notices/resource_limits_server_notices.py b/synapse/server_notices/resource_limits_server_notices.py
index c0e7f475c9..9fae2e0afe 100644
--- a/synapse/server_notices/resource_limits_server_notices.py
+++ b/synapse/server_notices/resource_limits_server_notices.py
@@ -83,7 +83,7 @@ class ResourceLimitsServerNotices(object):
         room_id = yield self._server_notices_manager.get_notice_room_for_user(user_id)
 
         if not room_id:
-            logger.warn("Failed to get server notices room")
+            logger.warning("Failed to get server notices room")
             return
 
         yield self._check_and_set_tags(user_id, room_id)
diff --git a/synapse/spam_checker_api/__init__.py b/synapse/spam_checker_api/__init__.py
new file mode 100644
index 0000000000..efcc10f808
--- /dev/null
+++ b/synapse/spam_checker_api/__init__.py
@@ -0,0 +1,51 @@
+# -*- coding: utf-8 -*-
+# Copyright 2019 The Matrix.org Foundation C.I.C.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+import logging
+
+from twisted.internet import defer
+
+from synapse.storage.state import StateFilter
+
+logger = logging.getLogger(__name__)
+
+
+class SpamCheckerApi(object):
+    """A proxy object that gets passed to spam checkers so they can get
+    access to rooms and other relevant information.
+    """
+
+    def __init__(self, hs):
+        self.hs = hs
+
+        self._store = hs.get_datastore()
+
+    @defer.inlineCallbacks
+    def get_state_events_in_room(self, room_id, types):
+        """Gets state events for the given room.
+
+        Args:
+            room_id (string): The room ID to get state events in.
+            types (tuple): The event type and state key (using None
+                to represent 'any') of the room state to acquire.
+
+        Returns:
+            twisted.internet.defer.Deferred[list(synapse.events.FrozenEvent)]:
+                The filtered state events in the room.
+        """
+        state_ids = yield self._store.get_filtered_current_state_ids(
+            room_id=room_id, state_filter=StateFilter.from_types(types)
+        )
+        state = yield self._store.get_events(state_ids.values())
+        return state.values()
diff --git a/synapse/state/__init__.py b/synapse/state/__init__.py
index dc9f5a9008..139beef8ed 100644
--- a/synapse/state/__init__.py
+++ b/synapse/state/__init__.py
@@ -16,6 +16,7 @@
 
 import logging
 from collections import namedtuple
+from typing import Iterable, Optional
 
 from six import iteritems, itervalues
 
@@ -27,6 +28,7 @@ from twisted.internet import defer
 
 from synapse.api.constants import EventTypes
 from synapse.api.room_versions import KNOWN_ROOM_VERSIONS, StateResolutionVersions
+from synapse.events import EventBase
 from synapse.events.snapshot import EventContext
 from synapse.logging.utils import log_function
 from synapse.state import v1, v2
@@ -103,6 +105,7 @@ class StateHandler(object):
     def __init__(self, hs):
         self.clock = hs.get_clock()
         self.store = hs.get_datastore()
+        self.state_store = hs.get_storage().state
         self.hs = hs
         self._state_resolution_handler = hs.get_state_resolution_handler()
 
@@ -211,15 +214,17 @@ class StateHandler(object):
         return joined_hosts
 
     @defer.inlineCallbacks
-    def compute_event_context(self, event, old_state=None):
+    def compute_event_context(
+        self, event: EventBase, old_state: Optional[Iterable[EventBase]] = None
+    ):
         """Build an EventContext structure for the event.
 
         This works out what the current state should be for the event, and
         generates a new state group if necessary.
 
         Args:
-            event (synapse.events.EventBase):
-            old_state (dict|None): The state at the event if it can't be
+            event:
+            old_state: The state at the event if it can't be
                 calculated from existing events. This is normally only specified
                 when receiving an event from federation where we don't have the
                 prev events for, e.g. when backfilling.
@@ -231,6 +236,9 @@ class StateHandler(object):
             # If this is an outlier, then we know it shouldn't have any current
             # state. Certainly store.get_current_state won't return any, and
             # persisting the event won't store the state group.
+
+            # FIXME: why do we populate current_state_ids? I thought the point was
+            # that we weren't supposed to have any state for outliers?
             if old_state:
                 prev_state_ids = {(s.type, s.state_key): s.event_id for s in old_state}
                 if event.is_state():
@@ -247,113 +255,103 @@ class StateHandler(object):
             # group for it.
             context = EventContext.with_state(
                 state_group=None,
+                state_group_before_event=None,
                 current_state_ids=current_state_ids,
                 prev_state_ids=prev_state_ids,
             )
 
             return context
 
+        #
+        # first of all, figure out the state before the event
+        #
+
         if old_state:
-            # We already have the state, so we don't need to calculate it.
-            # Let's just correctly fill out the context and create a
-            # new state group for it.
-
-            prev_state_ids = {(s.type, s.state_key): s.event_id for s in old_state}
-
-            if event.is_state():
-                key = (event.type, event.state_key)
-                if key in prev_state_ids:
-                    replaces = prev_state_ids[key]
-                    if replaces != event.event_id:  # Paranoia check
-                        event.unsigned["replaces_state"] = replaces
-                current_state_ids = dict(prev_state_ids)
-                current_state_ids[key] = event.event_id
-            else:
-                current_state_ids = prev_state_ids
+            # if we're given the state before the event, then we use that
+            state_ids_before_event = {
+                (s.type, s.state_key): s.event_id for s in old_state
+            }
+            state_group_before_event = None
+            state_group_before_event_prev_group = None
+            deltas_to_state_group_before_event = None
 
-            state_group = yield self.store.store_state_group(
-                event.event_id,
-                event.room_id,
-                prev_group=None,
-                delta_ids=None,
-                current_state_ids=current_state_ids,
-            )
+        else:
+            # otherwise, we'll need to resolve the state across the prev_events.
+            logger.debug("calling resolve_state_groups from compute_event_context")
 
-            context = EventContext.with_state(
-                state_group=state_group,
-                current_state_ids=current_state_ids,
-                prev_state_ids=prev_state_ids,
+            entry = yield self.resolve_state_groups_for_events(
+                event.room_id, event.prev_event_ids()
             )
 
-            return context
+            state_ids_before_event = entry.state
+            state_group_before_event = entry.state_group
+            state_group_before_event_prev_group = entry.prev_group
+            deltas_to_state_group_before_event = entry.delta_ids
 
-        logger.debug("calling resolve_state_groups from compute_event_context")
+        #
+        # make sure that we have a state group at that point. If it's not a state event,
+        # that will be the state group for the new event. If it *is* a state event,
+        # it might get rejected (in which case we'll need to persist it with the
+        # previous state group)
+        #
 
-        entry = yield self.resolve_state_groups_for_events(
-            event.room_id, event.prev_event_ids()
-        )
+        if not state_group_before_event:
+            state_group_before_event = yield self.state_store.store_state_group(
+                event.event_id,
+                event.room_id,
+                prev_group=state_group_before_event_prev_group,
+                delta_ids=deltas_to_state_group_before_event,
+                current_state_ids=state_ids_before_event,
+            )
 
-        prev_state_ids = entry.state
-        prev_group = None
-        delta_ids = None
+            # XXX: can we update the state cache entry for the new state group? or
+            # could we set a flag on resolve_state_groups_for_events to tell it to
+            # always make a state group?
+
+        #
+        # now if it's not a state event, we're done
+        #
+
+        if not event.is_state():
+            return EventContext.with_state(
+                state_group_before_event=state_group_before_event,
+                state_group=state_group_before_event,
+                current_state_ids=state_ids_before_event,
+                prev_state_ids=state_ids_before_event,
+                prev_group=state_group_before_event_prev_group,
+                delta_ids=deltas_to_state_group_before_event,
+            )
 
-        if event.is_state():
-            # If this is a state event then we need to create a new state
-            # group for the state after this event.
+        #
+        # otherwise, we'll need to create a new state group for after the event
+        #
 
-            key = (event.type, event.state_key)
-            if key in prev_state_ids:
-                replaces = prev_state_ids[key]
+        key = (event.type, event.state_key)
+        if key in state_ids_before_event:
+            replaces = state_ids_before_event[key]
+            if replaces != event.event_id:
                 event.unsigned["replaces_state"] = replaces
 
-            current_state_ids = dict(prev_state_ids)
-            current_state_ids[key] = event.event_id
-
-            if entry.state_group:
-                # If the state at the event has a state group assigned then
-                # we can use that as the prev group
-                prev_group = entry.state_group
-                delta_ids = {key: event.event_id}
-            elif entry.prev_group:
-                # If the state at the event only has a prev group, then we can
-                # use that as a prev group too.
-                prev_group = entry.prev_group
-                delta_ids = dict(entry.delta_ids)
-                delta_ids[key] = event.event_id
-
-            state_group = yield self.store.store_state_group(
-                event.event_id,
-                event.room_id,
-                prev_group=prev_group,
-                delta_ids=delta_ids,
-                current_state_ids=current_state_ids,
-            )
-        else:
-            current_state_ids = prev_state_ids
-            prev_group = entry.prev_group
-            delta_ids = entry.delta_ids
-
-            if entry.state_group is None:
-                entry.state_group = yield self.store.store_state_group(
-                    event.event_id,
-                    event.room_id,
-                    prev_group=entry.prev_group,
-                    delta_ids=entry.delta_ids,
-                    current_state_ids=current_state_ids,
-                )
-                entry.state_id = entry.state_group
-
-            state_group = entry.state_group
-
-        context = EventContext.with_state(
-            state_group=state_group,
-            current_state_ids=current_state_ids,
-            prev_state_ids=prev_state_ids,
-            prev_group=prev_group,
+        state_ids_after_event = dict(state_ids_before_event)
+        state_ids_after_event[key] = event.event_id
+        delta_ids = {key: event.event_id}
+
+        state_group_after_event = yield self.state_store.store_state_group(
+            event.event_id,
+            event.room_id,
+            prev_group=state_group_before_event,
             delta_ids=delta_ids,
+            current_state_ids=state_ids_after_event,
         )
 
-        return context
+        return EventContext.with_state(
+            state_group=state_group_after_event,
+            state_group_before_event=state_group_before_event,
+            current_state_ids=state_ids_after_event,
+            prev_state_ids=state_ids_before_event,
+            prev_group=state_group_before_event,
+            delta_ids=delta_ids,
+        )
 
     @measure_func()
     @defer.inlineCallbacks
@@ -376,14 +374,16 @@ class StateHandler(object):
         # map from state group id to the state in that state group (where
         # 'state' is a map from state key to event id)
         # dict[int, dict[(str, str), str]]
-        state_groups_ids = yield self.store.get_state_groups_ids(room_id, event_ids)
+        state_groups_ids = yield self.state_store.get_state_groups_ids(
+            room_id, event_ids
+        )
 
         if len(state_groups_ids) == 0:
             return _StateCacheEntry(state={}, state_group=None)
         elif len(state_groups_ids) == 1:
             name, state_list = list(state_groups_ids.items()).pop()
 
-            prev_group, delta_ids = yield self.store.get_state_group_delta(name)
+            prev_group, delta_ids = yield self.state_store.get_state_group_delta(name)
 
             return _StateCacheEntry(
                 state=state_list,
diff --git a/synapse/storage/__init__.py b/synapse/storage/__init__.py
index a249ecd219..0a1a8cc1e5 100644
--- a/synapse/storage/__init__.py
+++ b/synapse/storage/__init__.py
@@ -27,7 +27,26 @@ data stores associated with them (e.g. the schema version tables), which are
 stored in `synapse.storage.schema`.
 """
 
-from synapse.storage.data_stores.main import DataStore  # noqa: F401
+from synapse.storage.data_stores import DataStores
+from synapse.storage.data_stores.main import DataStore
+from synapse.storage.persist_events import EventsPersistenceStorage
+from synapse.storage.state import StateGroupStorage
+
+__all__ = ["DataStores", "DataStore"]
+
+
+class Storage(object):
+    """The high level interfaces for talking to various storage layers.
+    """
+
+    def __init__(self, hs, stores: DataStores):
+        # We include the main data store here mainly so that we don't have to
+        # rewrite all the existing code to split it into high vs low level
+        # interfaces.
+        self.main = stores.main
+
+        self.persistence = EventsPersistenceStorage(hs, stores)
+        self.state = StateGroupStorage(hs, stores)
 
 
 def are_all_users_on_domain(txn, database_engine, domain):
diff --git a/synapse/storage/_base.py b/synapse/storage/_base.py
index f5906fcd54..1a2b7ebe25 100644
--- a/synapse/storage/_base.py
+++ b/synapse/storage/_base.py
@@ -494,7 +494,7 @@ class SQLBaseStore(object):
         exception_callbacks = []
 
         if LoggingContext.current_context() == LoggingContext.sentinel:
-            logger.warn("Starting db txn '%s' from sentinel context", desc)
+            logger.warning("Starting db txn '%s' from sentinel context", desc)
 
         try:
             result = yield self.runWithConnection(
@@ -532,7 +532,7 @@ class SQLBaseStore(object):
         """
         parent_context = LoggingContext.current_context()
         if parent_context == LoggingContext.sentinel:
-            logger.warn(
+            logger.warning(
                 "Starting db connection from sentinel context: metrics will be lost"
             )
             parent_context = None
@@ -719,7 +719,7 @@ class SQLBaseStore(object):
                     raise
 
                 # presumably we raced with another transaction: let's retry.
-                logger.warn(
+                logger.warning(
                     "IntegrityError when upserting into %s; retrying: %s", table, e
                 )
 
diff --git a/synapse/storage/background_updates.py b/synapse/storage/background_updates.py
index 80b57a948c..37d469ffd7 100644
--- a/synapse/storage/background_updates.py
+++ b/synapse/storage/background_updates.py
@@ -94,13 +94,16 @@ class BackgroundUpdateStore(SQLBaseStore):
         self._all_done = False
 
     def start_doing_background_updates(self):
-        run_as_background_process("background_updates", self._run_background_updates)
+        run_as_background_process("background_updates", self.run_background_updates)
 
     @defer.inlineCallbacks
-    def _run_background_updates(self):
+    def run_background_updates(self, sleep=True):
         logger.info("Starting background schema updates")
         while True:
-            yield self.hs.get_clock().sleep(self.BACKGROUND_UPDATE_INTERVAL_MS / 1000.0)
+            if sleep:
+                yield self.hs.get_clock().sleep(
+                    self.BACKGROUND_UPDATE_INTERVAL_MS / 1000.0
+                )
 
             try:
                 result = yield self.do_next_background_update(
diff --git a/synapse/storage/data_stores/__init__.py b/synapse/storage/data_stores/__init__.py
index 56094078ed..cb184a98cc 100644
--- a/synapse/storage/data_stores/__init__.py
+++ b/synapse/storage/data_stores/__init__.py
@@ -12,3 +12,15 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+
+
+class DataStores(object):
+    """The various data stores.
+
+    These are low level interfaces to physical databases.
+    """
+
+    def __init__(self, main_store, db_conn, hs):
+        # Note we pass in the main store here as workers use a different main
+        # store.
+        self.main = main_store
diff --git a/synapse/storage/data_stores/main/__init__.py b/synapse/storage/data_stores/main/__init__.py
index b185ba0b3e..10c940df1e 100644
--- a/synapse/storage/data_stores/main/__init__.py
+++ b/synapse/storage/data_stores/main/__init__.py
@@ -139,7 +139,10 @@ class DataStore(
             db_conn, "public_room_list_stream", "stream_id"
         )
         self._device_list_id_gen = StreamIdGenerator(
-            db_conn, "device_lists_stream", "stream_id"
+            db_conn,
+            "device_lists_stream",
+            "stream_id",
+            extra_tables=[("user_signature_stream", "stream_id")],
         )
         self._cross_signing_id_gen = StreamIdGenerator(
             db_conn, "e2e_cross_signing_keys", "stream_id"
@@ -317,7 +320,7 @@ class DataStore(
             ) u
         """
         txn.execute(sql, (time_from,))
-        count, = txn.fetchone()
+        (count,) = txn.fetchone()
         return count
 
     def count_r30_users(self):
@@ -396,7 +399,7 @@ class DataStore(
 
             txn.execute(sql, (thirty_days_ago_in_secs, thirty_days_ago_in_secs))
 
-            count, = txn.fetchone()
+            (count,) = txn.fetchone()
             results["all"] = count
 
             return results
diff --git a/synapse/storage/data_stores/main/devices.py b/synapse/storage/data_stores/main/devices.py
index f7a3542348..71f62036c0 100644
--- a/synapse/storage/data_stores/main/devices.py
+++ b/synapse/storage/data_stores/main/devices.py
@@ -37,6 +37,7 @@ from synapse.storage._base import (
     make_in_list_sql_clause,
 )
 from synapse.storage.background_updates import BackgroundUpdateStore
+from synapse.types import get_verify_key_from_cross_signing_key
 from synapse.util import batch_iter
 from synapse.util.caches.descriptors import cached, cachedInlineCallbacks, cachedList
 
@@ -90,13 +91,18 @@ class DeviceWorkerStore(SQLBaseStore):
 
     @trace
     @defer.inlineCallbacks
-    def get_devices_by_remote(self, destination, from_stream_id, limit):
-        """Get stream of updates to send to remote servers
+    def get_device_updates_by_remote(self, destination, from_stream_id, limit):
+        """Get a stream of device updates to send to the given remote server.
 
+        Args:
+            destination (str): The host the device updates are intended for
+            from_stream_id (int): The minimum stream_id to filter updates by, exclusive
+            limit (int): Maximum number of device updates to return
         Returns:
-            Deferred[tuple[int, list[dict]]]:
+            Deferred[tuple[int, list[tuple[string,dict]]]]:
                 current stream id (ie, the stream id of the last update included in the
-                response), and the list of updates
+                response), and the list of updates, where each update is a pair of EDU
+                type and EDU contents
         """
         now_stream_id = self._device_list_id_gen.get_current_token()
 
@@ -117,8 +123,8 @@ class DeviceWorkerStore(SQLBaseStore):
         # stream_id; the rationale being that such a large device list update
         # is likely an error.
         updates = yield self.runInteraction(
-            "get_devices_by_remote",
-            self._get_devices_by_remote_txn,
+            "get_device_updates_by_remote",
+            self._get_device_updates_by_remote_txn,
             destination,
             from_stream_id,
             now_stream_id,
@@ -129,6 +135,37 @@ class DeviceWorkerStore(SQLBaseStore):
         if not updates:
             return now_stream_id, []
 
+        # get the cross-signing keys of the users in the list, so that we can
+        # determine which of the device changes were cross-signing keys
+        users = set(r[0] for r in updates)
+        master_key_by_user = {}
+        self_signing_key_by_user = {}
+        for user in users:
+            cross_signing_key = yield self.get_e2e_cross_signing_key(user, "master")
+            if cross_signing_key:
+                key_id, verify_key = get_verify_key_from_cross_signing_key(
+                    cross_signing_key
+                )
+                # verify_key is a VerifyKey from signedjson, which uses
+                # .version to denote the portion of the key ID after the
+                # algorithm and colon, which is the device ID
+                master_key_by_user[user] = {
+                    "key_info": cross_signing_key,
+                    "device_id": verify_key.version,
+                }
+
+            cross_signing_key = yield self.get_e2e_cross_signing_key(
+                user, "self_signing"
+            )
+            if cross_signing_key:
+                key_id, verify_key = get_verify_key_from_cross_signing_key(
+                    cross_signing_key
+                )
+                self_signing_key_by_user[user] = {
+                    "key_info": cross_signing_key,
+                    "device_id": verify_key.version,
+                }
+
         # if we have exceeded the limit, we need to exclude any results with the
         # same stream_id as the last row.
         if len(updates) > limit:
@@ -153,20 +190,33 @@ class DeviceWorkerStore(SQLBaseStore):
         # context which created the Edu.
 
         query_map = {}
-        for update in updates:
-            if stream_id_cutoff is not None and update[2] >= stream_id_cutoff:
+        cross_signing_keys_by_user = {}
+        for user_id, device_id, update_stream_id, update_context in updates:
+            if stream_id_cutoff is not None and update_stream_id >= stream_id_cutoff:
                 # Stop processing updates
                 break
 
-            key = (update[0], update[1])
-
-            update_context = update[3]
-            update_stream_id = update[2]
+            if (
+                user_id in master_key_by_user
+                and device_id == master_key_by_user[user_id]["device_id"]
+            ):
+                result = cross_signing_keys_by_user.setdefault(user_id, {})
+                result["master_key"] = master_key_by_user[user_id]["key_info"]
+            elif (
+                user_id in self_signing_key_by_user
+                and device_id == self_signing_key_by_user[user_id]["device_id"]
+            ):
+                result = cross_signing_keys_by_user.setdefault(user_id, {})
+                result["self_signing_key"] = self_signing_key_by_user[user_id][
+                    "key_info"
+                ]
+            else:
+                key = (user_id, device_id)
 
-            previous_update_stream_id, _ = query_map.get(key, (0, None))
+                previous_update_stream_id, _ = query_map.get(key, (0, None))
 
-            if update_stream_id > previous_update_stream_id:
-                query_map[key] = (update_stream_id, update_context)
+                if update_stream_id > previous_update_stream_id:
+                    query_map[key] = (update_stream_id, update_context)
 
         # If we didn't find any updates with a stream_id lower than the cutoff, it
         # means that there are more than limit updates all of which have the same
@@ -176,16 +226,22 @@ class DeviceWorkerStore(SQLBaseStore):
         # devices, in which case E2E isn't going to work well anyway. We'll just
         # skip that stream_id and return an empty list, and continue with the next
         # stream_id next time.
-        if not query_map:
+        if not query_map and not cross_signing_keys_by_user:
             return stream_id_cutoff, []
 
         results = yield self._get_device_update_edus_by_remote(
             destination, from_stream_id, query_map
         )
 
+        # add the updated cross-signing keys to the results list
+        for user_id, result in iteritems(cross_signing_keys_by_user):
+            result["user_id"] = user_id
+            # FIXME: switch to m.signing_key_update when MSC1756 is merged into the spec
+            results.append(("org.matrix.signing_key_update", result))
+
         return now_stream_id, results
 
-    def _get_devices_by_remote_txn(
+    def _get_device_updates_by_remote_txn(
         self, txn, destination, from_stream_id, now_stream_id, limit
     ):
         """Return device update information for a given remote destination
@@ -200,6 +256,7 @@ class DeviceWorkerStore(SQLBaseStore):
         Returns:
             List: List of device updates
         """
+        # get the list of device updates that need to be sent
         sql = """
             SELECT user_id, device_id, stream_id, opentracing_context FROM device_lists_outbound_pokes
             WHERE destination = ? AND ? < stream_id AND stream_id <= ? AND sent = ?
@@ -225,12 +282,16 @@ class DeviceWorkerStore(SQLBaseStore):
             List[Dict]: List of objects representing an device update EDU
 
         """
-        devices = yield self.runInteraction(
-            "_get_e2e_device_keys_txn",
-            self._get_e2e_device_keys_txn,
-            query_map.keys(),
-            include_all_devices=True,
-            include_deleted_devices=True,
+        devices = (
+            yield self.runInteraction(
+                "_get_e2e_device_keys_txn",
+                self._get_e2e_device_keys_txn,
+                query_map.keys(),
+                include_all_devices=True,
+                include_deleted_devices=True,
+            )
+            if query_map
+            else {}
         )
 
         results = []
@@ -262,7 +323,7 @@ class DeviceWorkerStore(SQLBaseStore):
                 else:
                     result["deleted"] = True
 
-                results.append(result)
+                results.append(("m.device_list_update", result))
 
         return results
 
diff --git a/synapse/storage/data_stores/main/e2e_room_keys.py b/synapse/storage/data_stores/main/e2e_room_keys.py
index ef88e79293..1cbbae5b63 100644
--- a/synapse/storage/data_stores/main/e2e_room_keys.py
+++ b/synapse/storage/data_stores/main/e2e_room_keys.py
@@ -321,9 +321,17 @@ class EndToEndRoomKeyStore(SQLBaseStore):
         def _delete_e2e_room_keys_version_txn(txn):
             if version is None:
                 this_version = self._get_current_version(txn, user_id)
+                if this_version is None:
+                    raise StoreError(404, "No current backup version")
             else:
                 this_version = version
 
+            self._simple_delete_txn(
+                txn,
+                table="e2e_room_keys",
+                keyvalues={"user_id": user_id, "version": this_version},
+            )
+
             return self._simple_update_one_txn(
                 txn,
                 table="e2e_room_keys_versions",
diff --git a/synapse/storage/data_stores/main/end_to_end_keys.py b/synapse/storage/data_stores/main/end_to_end_keys.py
index a0bc6f2d18..073412a78d 100644
--- a/synapse/storage/data_stores/main/end_to_end_keys.py
+++ b/synapse/storage/data_stores/main/end_to_end_keys.py
@@ -315,6 +315,30 @@ class EndToEndKeyWorkerStore(SQLBaseStore):
             from_user_id,
         )
 
+    def get_all_user_signature_changes_for_remotes(self, from_key, to_key):
+        """Return a list of changes from the user signature stream to notify remotes.
+        Note that the user signature stream represents when a user signs their
+        device with their user-signing key, which is not published to other
+        users or servers, so no `destination` is needed in the returned
+        list. However, this is needed to poke workers.
+
+        Args:
+            from_key (int): the stream ID to start at (exclusive)
+            to_key (int): the stream ID to end at (inclusive)
+
+        Returns:
+            Deferred[list[(int,str)]] a list of `(stream_id, user_id)`
+        """
+        sql = """
+            SELECT MAX(stream_id) AS stream_id, from_user_id AS user_id
+            FROM user_signature_stream
+            WHERE ? < stream_id AND stream_id <= ?
+            GROUP BY user_id
+        """
+        return self._execute(
+            "get_all_user_signature_changes_for_remotes", None, sql, from_key, to_key
+        )
+
 
 class EndToEndKeyStore(EndToEndKeyWorkerStore, SQLBaseStore):
     def set_e2e_device_keys(self, user_id, device_id, time_now, device_keys):
diff --git a/synapse/storage/data_stores/main/event_federation.py b/synapse/storage/data_stores/main/event_federation.py
index a470a48e0f..90bef0cd2c 100644
--- a/synapse/storage/data_stores/main/event_federation.py
+++ b/synapse/storage/data_stores/main/event_federation.py
@@ -364,9 +364,7 @@ class EventFederationWorkerStore(EventsWorkerStore, SignatureWorkerStore, SQLBas
         )
 
     def _get_backfill_events(self, txn, room_id, event_list, limit):
-        logger.debug(
-            "_get_backfill_events: %s, %s, %s", room_id, repr(event_list), limit
-        )
+        logger.debug("_get_backfill_events: %s, %r, %s", room_id, event_list, limit)
 
         event_results = set()
 
diff --git a/synapse/storage/data_stores/main/event_push_actions.py b/synapse/storage/data_stores/main/event_push_actions.py
index 22025effbc..04ce21ac66 100644
--- a/synapse/storage/data_stores/main/event_push_actions.py
+++ b/synapse/storage/data_stores/main/event_push_actions.py
@@ -863,7 +863,7 @@ class EventPushActionsStore(EventPushActionsWorkerStore):
         )
         stream_row = txn.fetchone()
         if stream_row:
-            offset_stream_ordering, = stream_row
+            (offset_stream_ordering,) = stream_row
             rotate_to_stream_ordering = min(
                 self.stream_ordering_day_ago, offset_stream_ordering
             )
diff --git a/synapse/storage/data_stores/main/events.py b/synapse/storage/data_stores/main/events.py
index 03b5111c5d..301f8ea128 100644
--- a/synapse/storage/data_stores/main/events.py
+++ b/synapse/storage/data_stores/main/events.py
@@ -17,28 +17,26 @@
 
 import itertools
 import logging
-from collections import Counter as c_counter, OrderedDict, deque, namedtuple
+from collections import Counter as c_counter, OrderedDict, namedtuple
 from functools import wraps
 
 from six import iteritems, text_type
 from six.moves import range
 
 from canonicaljson import json
-from prometheus_client import Counter, Histogram
+from prometheus_client import Counter
 
 from twisted.internet import defer
 
 import synapse.metrics
-from synapse.api.constants import EventTypes
+from synapse.api.constants import EventContentFields, EventTypes
 from synapse.api.errors import SynapseError
 from synapse.events import EventBase  # noqa: F401
 from synapse.events.snapshot import EventContext  # noqa: F401
 from synapse.events.utils import prune_event_dict
-from synapse.logging.context import PreserveLoggingContext, make_deferred_yieldable
 from synapse.logging.utils import log_function
 from synapse.metrics import BucketCollector
 from synapse.metrics.background_process_metrics import run_as_background_process
-from synapse.state import StateResolutionStore
 from synapse.storage._base import make_in_list_sql_clause
 from synapse.storage.background_updates import BackgroundUpdateStore
 from synapse.storage.data_stores.main.event_federation import EventFederationStore
@@ -46,10 +44,8 @@ from synapse.storage.data_stores.main.events_worker import EventsWorkerStore
 from synapse.storage.data_stores.main.state import StateGroupWorkerStore
 from synapse.types import RoomStreamToken, get_domain_from_id
 from synapse.util import batch_iter
-from synapse.util.async_helpers import ObservableDeferred
 from synapse.util.caches.descriptors import cached, cachedInlineCallbacks
 from synapse.util.frozenutils import frozendict_json_encoder
-from synapse.util.metrics import Measure
 
 logger = logging.getLogger(__name__)
 
@@ -60,37 +56,6 @@ event_counter = Counter(
     ["type", "origin_type", "origin_entity"],
 )
 
-# The number of times we are recalculating the current state
-state_delta_counter = Counter("synapse_storage_events_state_delta", "")
-
-# The number of times we are recalculating state when there is only a
-# single forward extremity
-state_delta_single_event_counter = Counter(
-    "synapse_storage_events_state_delta_single_event", ""
-)
-
-# The number of times we are reculating state when we could have resonably
-# calculated the delta when we calculated the state for an event we were
-# persisting.
-state_delta_reuse_delta_counter = Counter(
-    "synapse_storage_events_state_delta_reuse_delta", ""
-)
-
-# The number of forward extremities for each new event.
-forward_extremities_counter = Histogram(
-    "synapse_storage_events_forward_extremities_persisted",
-    "Number of forward extremities for each new event",
-    buckets=(1, 2, 3, 5, 7, 10, 15, 20, 50, 100, 200, 500, "+Inf"),
-)
-
-# The number of stale forward extremities for each new event. Stale extremities
-# are those that were in the previous set of extremities as well as the new.
-stale_forward_extremities_counter = Histogram(
-    "synapse_storage_events_stale_forward_extremities_persisted",
-    "Number of unchanged forward extremities for each new event",
-    buckets=(0, 1, 2, 3, 5, 7, 10, 15, 20, 50, 100, 200, 500, "+Inf"),
-)
-
 
 def encode_json(json_object):
     """
@@ -102,110 +67,6 @@ def encode_json(json_object):
     return out
 
 
-class _EventPeristenceQueue(object):
-    """Queues up events so that they can be persisted in bulk with only one
-    concurrent transaction per room.
-    """
-
-    _EventPersistQueueItem = namedtuple(
-        "_EventPersistQueueItem", ("events_and_contexts", "backfilled", "deferred")
-    )
-
-    def __init__(self):
-        self._event_persist_queues = {}
-        self._currently_persisting_rooms = set()
-
-    def add_to_queue(self, room_id, events_and_contexts, backfilled):
-        """Add events to the queue, with the given persist_event options.
-
-        NB: due to the normal usage pattern of this method, it does *not*
-        follow the synapse logcontext rules, and leaves the logcontext in
-        place whether or not the returned deferred is ready.
-
-        Args:
-            room_id (str):
-            events_and_contexts (list[(EventBase, EventContext)]):
-            backfilled (bool):
-
-        Returns:
-            defer.Deferred: a deferred which will resolve once the events are
-                persisted. Runs its callbacks *without* a logcontext.
-        """
-        queue = self._event_persist_queues.setdefault(room_id, deque())
-        if queue:
-            # if the last item in the queue has the same `backfilled` setting,
-            # we can just add these new events to that item.
-            end_item = queue[-1]
-            if end_item.backfilled == backfilled:
-                end_item.events_and_contexts.extend(events_and_contexts)
-                return end_item.deferred.observe()
-
-        deferred = ObservableDeferred(defer.Deferred(), consumeErrors=True)
-
-        queue.append(
-            self._EventPersistQueueItem(
-                events_and_contexts=events_and_contexts,
-                backfilled=backfilled,
-                deferred=deferred,
-            )
-        )
-
-        return deferred.observe()
-
-    def handle_queue(self, room_id, per_item_callback):
-        """Attempts to handle the queue for a room if not already being handled.
-
-        The given callback will be invoked with for each item in the queue,
-        of type _EventPersistQueueItem. The per_item_callback will continuously
-        be called with new items, unless the queue becomnes empty. The return
-        value of the function will be given to the deferreds waiting on the item,
-        exceptions will be passed to the deferreds as well.
-
-        This function should therefore be called whenever anything is added
-        to the queue.
-
-        If another callback is currently handling the queue then it will not be
-        invoked.
-        """
-
-        if room_id in self._currently_persisting_rooms:
-            return
-
-        self._currently_persisting_rooms.add(room_id)
-
-        @defer.inlineCallbacks
-        def handle_queue_loop():
-            try:
-                queue = self._get_drainining_queue(room_id)
-                for item in queue:
-                    try:
-                        ret = yield per_item_callback(item)
-                    except Exception:
-                        with PreserveLoggingContext():
-                            item.deferred.errback()
-                    else:
-                        with PreserveLoggingContext():
-                            item.deferred.callback(ret)
-            finally:
-                queue = self._event_persist_queues.pop(room_id, None)
-                if queue:
-                    self._event_persist_queues[room_id] = queue
-                self._currently_persisting_rooms.discard(room_id)
-
-        # set handle_queue_loop off in the background
-        run_as_background_process("persist_events", handle_queue_loop)
-
-    def _get_drainining_queue(self, room_id):
-        queue = self._event_persist_queues.setdefault(room_id, deque())
-
-        try:
-            while True:
-                yield queue.popleft()
-        except IndexError:
-            # Queue has been drained.
-            pass
-
-
 _EventCacheEntry = namedtuple("_EventCacheEntry", ("event", "redacted_event"))
 
 
@@ -221,7 +82,7 @@ def _retry_on_integrity_error(func):
     @defer.inlineCallbacks
     def f(self, *args, **kwargs):
         try:
-            res = yield func(self, *args, **kwargs)
+            res = yield func(self, *args, delete_existing=False, **kwargs)
         except self.database_engine.module.IntegrityError:
             logger.exception("IntegrityError, retrying.")
             res = yield func(self, *args, delete_existing=True, **kwargs)
@@ -241,9 +102,6 @@ class EventsStore(
     def __init__(self, db_conn, hs):
         super(EventsStore, self).__init__(db_conn, hs)
 
-        self._event_persist_queue = _EventPeristenceQueue()
-        self._state_resolution_handler = hs.get_state_resolution_handler()
-
         # Collect metrics on the number of forward extremities that exist.
         # Counter of number of extremities to count
         self._current_forward_extremities_amount = c_counter()
@@ -286,340 +144,106 @@ class EventsStore(
         res = yield self.runInteraction("read_forward_extremities", fetch)
         self._current_forward_extremities_amount = c_counter(list(x[0] for x in res))
 
-    @defer.inlineCallbacks
-    def persist_events(self, events_and_contexts, backfilled=False):
-        """
-        Write events to the database
-        Args:
-            events_and_contexts: list of tuples of (event, context)
-            backfilled (bool): Whether the results are retrieved from federation
-                via backfill or not. Used to determine if they're "new" events
-                which might update the current state etc.
-
-        Returns:
-            Deferred[int]: the stream ordering of the latest persisted event
-        """
-        partitioned = {}
-        for event, ctx in events_and_contexts:
-            partitioned.setdefault(event.room_id, []).append((event, ctx))
-
-        deferreds = []
-        for room_id, evs_ctxs in iteritems(partitioned):
-            d = self._event_persist_queue.add_to_queue(
-                room_id, evs_ctxs, backfilled=backfilled
-            )
-            deferreds.append(d)
-
-        for room_id in partitioned:
-            self._maybe_start_persisting(room_id)
-
-        yield make_deferred_yieldable(
-            defer.gatherResults(deferreds, consumeErrors=True)
-        )
-
-        max_persisted_id = yield self._stream_id_gen.get_current_token()
-
-        return max_persisted_id
-
-    @defer.inlineCallbacks
-    @log_function
-    def persist_event(self, event, context, backfilled=False):
-        """
-
-        Args:
-            event (EventBase):
-            context (EventContext):
-            backfilled (bool):
-
-        Returns:
-            Deferred: resolves to (int, int): the stream ordering of ``event``,
-            and the stream ordering of the latest persisted event
-        """
-        deferred = self._event_persist_queue.add_to_queue(
-            event.room_id, [(event, context)], backfilled=backfilled
-        )
-
-        self._maybe_start_persisting(event.room_id)
-
-        yield make_deferred_yieldable(deferred)
-
-        max_persisted_id = yield self._stream_id_gen.get_current_token()
-        return (event.internal_metadata.stream_ordering, max_persisted_id)
-
-    def _maybe_start_persisting(self, room_id):
-        @defer.inlineCallbacks
-        def persisting_queue(item):
-            with Measure(self._clock, "persist_events"):
-                yield self._persist_events(
-                    item.events_and_contexts, backfilled=item.backfilled
-                )
-
-        self._event_persist_queue.handle_queue(room_id, persisting_queue)
-
     @_retry_on_integrity_error
     @defer.inlineCallbacks
-    def _persist_events(
-        self, events_and_contexts, backfilled=False, delete_existing=False
+    def _persist_events_and_state_updates(
+        self,
+        events_and_contexts,
+        current_state_for_room,
+        state_delta_for_room,
+        new_forward_extremeties,
+        backfilled=False,
+        delete_existing=False,
     ):
-        """Persist events to db
+        """Persist a set of events alongside updates to the current state and
+        forward extremities tables.
 
         Args:
             events_and_contexts (list[(EventBase, EventContext)]):
-            backfilled (bool):
+            current_state_for_room (dict[str, dict]): Map from room_id to the
+                current state of the room based on forward extremities
+            state_delta_for_room (dict[str, tuple]): Map from room_id to tuple
+                of `(to_delete, to_insert)` where to_delete is a list
+                of type/state keys to remove from current state, and to_insert
+                is a map (type,key)->event_id giving the state delta in each
+                room.
+            new_forward_extremities (dict[str, list[str]]): Map from room_id
+                to list of event IDs that are the new forward extremities of
+                the room.
+            backfilled (bool)
             delete_existing (bool):
 
         Returns:
             Deferred: resolves when the events have been persisted
         """
-        if not events_and_contexts:
-            return
-
-        chunks = [
-            events_and_contexts[x : x + 100]
-            for x in range(0, len(events_and_contexts), 100)
-        ]
 
-        for chunk in chunks:
-            # We can't easily parallelize these since different chunks
-            # might contain the same event. :(
-
-            # NB: Assumes that we are only persisting events for one room
-            # at a time.
-
-            # map room_id->list[event_ids] giving the new forward
-            # extremities in each room
-            new_forward_extremeties = {}
+        # We want to calculate the stream orderings as late as possible, as
+        # we only notify after all events with a lesser stream ordering have
+        # been persisted. I.e. if we spend 10s inside the with block then
+        # that will delay all subsequent events from being notified about.
+        # Hence why we do it down here rather than wrapping the entire
+        # function.
+        #
+        # Its safe to do this after calculating the state deltas etc as we
+        # only need to protect the *persistence* of the events. This is to
+        # ensure that queries of the form "fetch events since X" don't
+        # return events and stream positions after events that are still in
+        # flight, as otherwise subsequent requests "fetch event since Y"
+        # will not return those events.
+        #
+        # Note: Multiple instances of this function cannot be in flight at
+        # the same time for the same room.
+        if backfilled:
+            stream_ordering_manager = self._backfill_id_gen.get_next_mult(
+                len(events_and_contexts)
+            )
+        else:
+            stream_ordering_manager = self._stream_id_gen.get_next_mult(
+                len(events_and_contexts)
+            )
 
-            # map room_id->(type,state_key)->event_id tracking the full
-            # state in each room after adding these events.
-            # This is simply used to prefill the get_current_state_ids
-            # cache
-            current_state_for_room = {}
+        with stream_ordering_manager as stream_orderings:
+            for (event, context), stream in zip(events_and_contexts, stream_orderings):
+                event.internal_metadata.stream_ordering = stream
 
-            # map room_id->(to_delete, to_insert) where to_delete is a list
-            # of type/state keys to remove from current state, and to_insert
-            # is a map (type,key)->event_id giving the state delta in each
-            # room
-            state_delta_for_room = {}
+            yield self.runInteraction(
+                "persist_events",
+                self._persist_events_txn,
+                events_and_contexts=events_and_contexts,
+                backfilled=backfilled,
+                delete_existing=delete_existing,
+                state_delta_for_room=state_delta_for_room,
+                new_forward_extremeties=new_forward_extremeties,
+            )
+            persist_event_counter.inc(len(events_and_contexts))
 
             if not backfilled:
-                with Measure(self._clock, "_calculate_state_and_extrem"):
-                    # Work out the new "current state" for each room.
-                    # We do this by working out what the new extremities are and then
-                    # calculating the state from that.
-                    events_by_room = {}
-                    for event, context in chunk:
-                        events_by_room.setdefault(event.room_id, []).append(
-                            (event, context)
-                        )
-
-                    for room_id, ev_ctx_rm in iteritems(events_by_room):
-                        latest_event_ids = yield self.get_latest_event_ids_in_room(
-                            room_id
-                        )
-                        new_latest_event_ids = yield self._calculate_new_extremities(
-                            room_id, ev_ctx_rm, latest_event_ids
-                        )
-
-                        latest_event_ids = set(latest_event_ids)
-                        if new_latest_event_ids == latest_event_ids:
-                            # No change in extremities, so no change in state
-                            continue
-
-                        # there should always be at least one forward extremity.
-                        # (except during the initial persistence of the send_join
-                        # results, in which case there will be no existing
-                        # extremities, so we'll `continue` above and skip this bit.)
-                        assert new_latest_event_ids, "No forward extremities left!"
-
-                        new_forward_extremeties[room_id] = new_latest_event_ids
-
-                        len_1 = (
-                            len(latest_event_ids) == 1
-                            and len(new_latest_event_ids) == 1
-                        )
-                        if len_1:
-                            all_single_prev_not_state = all(
-                                len(event.prev_event_ids()) == 1
-                                and not event.is_state()
-                                for event, ctx in ev_ctx_rm
-                            )
-                            # Don't bother calculating state if they're just
-                            # a long chain of single ancestor non-state events.
-                            if all_single_prev_not_state:
-                                continue
-
-                        state_delta_counter.inc()
-                        if len(new_latest_event_ids) == 1:
-                            state_delta_single_event_counter.inc()
-
-                            # This is a fairly handwavey check to see if we could
-                            # have guessed what the delta would have been when
-                            # processing one of these events.
-                            # What we're interested in is if the latest extremities
-                            # were the same when we created the event as they are
-                            # now. When this server creates a new event (as opposed
-                            # to receiving it over federation) it will use the
-                            # forward extremities as the prev_events, so we can
-                            # guess this by looking at the prev_events and checking
-                            # if they match the current forward extremities.
-                            for ev, _ in ev_ctx_rm:
-                                prev_event_ids = set(ev.prev_event_ids())
-                                if latest_event_ids == prev_event_ids:
-                                    state_delta_reuse_delta_counter.inc()
-                                    break
-
-                        logger.info("Calculating state delta for room %s", room_id)
-                        with Measure(
-                            self._clock, "persist_events.get_new_state_after_events"
-                        ):
-                            res = yield self._get_new_state_after_events(
-                                room_id,
-                                ev_ctx_rm,
-                                latest_event_ids,
-                                new_latest_event_ids,
-                            )
-                            current_state, delta_ids = res
-
-                        # If either are not None then there has been a change,
-                        # and we need to work out the delta (or use that
-                        # given)
-                        if delta_ids is not None:
-                            # If there is a delta we know that we've
-                            # only added or replaced state, never
-                            # removed keys entirely.
-                            state_delta_for_room[room_id] = ([], delta_ids)
-                        elif current_state is not None:
-                            with Measure(
-                                self._clock, "persist_events.calculate_state_delta"
-                            ):
-                                delta = yield self._calculate_state_delta(
-                                    room_id, current_state
-                                )
-                            state_delta_for_room[room_id] = delta
-
-                        # If we have the current_state then lets prefill
-                        # the cache with it.
-                        if current_state is not None:
-                            current_state_for_room[room_id] = current_state
-
-            # We want to calculate the stream orderings as late as possible, as
-            # we only notify after all events with a lesser stream ordering have
-            # been persisted. I.e. if we spend 10s inside the with block then
-            # that will delay all subsequent events from being notified about.
-            # Hence why we do it down here rather than wrapping the entire
-            # function.
-            #
-            # Its safe to do this after calculating the state deltas etc as we
-            # only need to protect the *persistence* of the events. This is to
-            # ensure that queries of the form "fetch events since X" don't
-            # return events and stream positions after events that are still in
-            # flight, as otherwise subsequent requests "fetch event since Y"
-            # will not return those events.
-            #
-            # Note: Multiple instances of this function cannot be in flight at
-            # the same time for the same room.
-            if backfilled:
-                stream_ordering_manager = self._backfill_id_gen.get_next_mult(
-                    len(chunk)
+                # backfilled events have negative stream orderings, so we don't
+                # want to set the event_persisted_position to that.
+                synapse.metrics.event_persisted_position.set(
+                    events_and_contexts[-1][0].internal_metadata.stream_ordering
                 )
-            else:
-                stream_ordering_manager = self._stream_id_gen.get_next_mult(len(chunk))
-
-            with stream_ordering_manager as stream_orderings:
-                for (event, context), stream in zip(chunk, stream_orderings):
-                    event.internal_metadata.stream_ordering = stream
-
-                yield self.runInteraction(
-                    "persist_events",
-                    self._persist_events_txn,
-                    events_and_contexts=chunk,
-                    backfilled=backfilled,
-                    delete_existing=delete_existing,
-                    state_delta_for_room=state_delta_for_room,
-                    new_forward_extremeties=new_forward_extremeties,
-                )
-                persist_event_counter.inc(len(chunk))
-
-                if not backfilled:
-                    # backfilled events have negative stream orderings, so we don't
-                    # want to set the event_persisted_position to that.
-                    synapse.metrics.event_persisted_position.set(
-                        chunk[-1][0].internal_metadata.stream_ordering
-                    )
-
-                for event, context in chunk:
-                    if context.app_service:
-                        origin_type = "local"
-                        origin_entity = context.app_service.id
-                    elif self.hs.is_mine_id(event.sender):
-                        origin_type = "local"
-                        origin_entity = "*client*"
-                    else:
-                        origin_type = "remote"
-                        origin_entity = get_domain_from_id(event.sender)
-
-                    event_counter.labels(event.type, origin_type, origin_entity).inc()
-
-                for room_id, new_state in iteritems(current_state_for_room):
-                    self.get_current_state_ids.prefill((room_id,), new_state)
-
-                for room_id, latest_event_ids in iteritems(new_forward_extremeties):
-                    self.get_latest_event_ids_in_room.prefill(
-                        (room_id,), list(latest_event_ids)
-                    )
-
-    @defer.inlineCallbacks
-    def _calculate_new_extremities(self, room_id, event_contexts, latest_event_ids):
-        """Calculates the new forward extremities for a room given events to
-        persist.
-
-        Assumes that we are only persisting events for one room at a time.
-        """
-
-        # we're only interested in new events which aren't outliers and which aren't
-        # being rejected.
-        new_events = [
-            event
-            for event, ctx in event_contexts
-            if not event.internal_metadata.is_outlier()
-            and not ctx.rejected
-            and not event.internal_metadata.is_soft_failed()
-        ]
-
-        latest_event_ids = set(latest_event_ids)
 
-        # start with the existing forward extremities
-        result = set(latest_event_ids)
-
-        # add all the new events to the list
-        result.update(event.event_id for event in new_events)
-
-        # Now remove all events which are prev_events of any of the new events
-        result.difference_update(
-            e_id for event in new_events for e_id in event.prev_event_ids()
-        )
-
-        # Remove any events which are prev_events of any existing events.
-        existing_prevs = yield self._get_events_which_are_prevs(result)
-        result.difference_update(existing_prevs)
+            for event, context in events_and_contexts:
+                if context.app_service:
+                    origin_type = "local"
+                    origin_entity = context.app_service.id
+                elif self.hs.is_mine_id(event.sender):
+                    origin_type = "local"
+                    origin_entity = "*client*"
+                else:
+                    origin_type = "remote"
+                    origin_entity = get_domain_from_id(event.sender)
 
-        # Finally handle the case where the new events have soft-failed prev
-        # events. If they do we need to remove them and their prev events,
-        # otherwise we end up with dangling extremities.
-        existing_prevs = yield self._get_prevs_before_rejected(
-            e_id for event in new_events for e_id in event.prev_event_ids()
-        )
-        result.difference_update(existing_prevs)
+                event_counter.labels(event.type, origin_type, origin_entity).inc()
 
-        # We only update metrics for events that change forward extremities
-        # (e.g. we ignore backfill/outliers/etc)
-        if result != latest_event_ids:
-            forward_extremities_counter.observe(len(result))
-            stale = latest_event_ids & result
-            stale_forward_extremities_counter.observe(len(stale))
+            for room_id, new_state in iteritems(current_state_for_room):
+                self.get_current_state_ids.prefill((room_id,), new_state)
 
-        return result
+            for room_id, latest_event_ids in iteritems(new_forward_extremeties):
+                self.get_latest_event_ids_in_room.prefill(
+                    (room_id,), list(latest_event_ids)
+                )
 
     @defer.inlineCallbacks
     def _get_events_which_are_prevs(self, event_ids):
@@ -725,188 +349,6 @@ class EventsStore(
 
         return existing_prevs
 
-    @defer.inlineCallbacks
-    def _get_new_state_after_events(
-        self, room_id, events_context, old_latest_event_ids, new_latest_event_ids
-    ):
-        """Calculate the current state dict after adding some new events to
-        a room
-
-        Args:
-            room_id (str):
-                room to which the events are being added. Used for logging etc
-
-            events_context (list[(EventBase, EventContext)]):
-                events and contexts which are being added to the room
-
-            old_latest_event_ids (iterable[str]):
-                the old forward extremities for the room.
-
-            new_latest_event_ids (iterable[str]):
-                the new forward extremities for the room.
-
-        Returns:
-            Deferred[tuple[dict[(str,str), str]|None, dict[(str,str), str]|None]]:
-            Returns a tuple of two state maps, the first being the full new current
-            state and the second being the delta to the existing current state.
-            If both are None then there has been no change.
-
-            If there has been a change then we only return the delta if its
-            already been calculated. Conversely if we do know the delta then
-            the new current state is only returned if we've already calculated
-            it.
-        """
-        # map from state_group to ((type, key) -> event_id) state map
-        state_groups_map = {}
-
-        # Map from (prev state group, new state group) -> delta state dict
-        state_group_deltas = {}
-
-        for ev, ctx in events_context:
-            if ctx.state_group is None:
-                # This should only happen for outlier events.
-                if not ev.internal_metadata.is_outlier():
-                    raise Exception(
-                        "Context for new event %s has no state "
-                        "group" % (ev.event_id,)
-                    )
-                continue
-
-            if ctx.state_group in state_groups_map:
-                continue
-
-            # We're only interested in pulling out state that has already
-            # been cached in the context. We'll pull stuff out of the DB later
-            # if necessary.
-            current_state_ids = ctx.get_cached_current_state_ids()
-            if current_state_ids is not None:
-                state_groups_map[ctx.state_group] = current_state_ids
-
-            if ctx.prev_group:
-                state_group_deltas[(ctx.prev_group, ctx.state_group)] = ctx.delta_ids
-
-        # We need to map the event_ids to their state groups. First, let's
-        # check if the event is one we're persisting, in which case we can
-        # pull the state group from its context.
-        # Otherwise we need to pull the state group from the database.
-
-        # Set of events we need to fetch groups for. (We know none of the old
-        # extremities are going to be in events_context).
-        missing_event_ids = set(old_latest_event_ids)
-
-        event_id_to_state_group = {}
-        for event_id in new_latest_event_ids:
-            # First search in the list of new events we're adding.
-            for ev, ctx in events_context:
-                if event_id == ev.event_id and ctx.state_group is not None:
-                    event_id_to_state_group[event_id] = ctx.state_group
-                    break
-            else:
-                # If we couldn't find it, then we'll need to pull
-                # the state from the database
-                missing_event_ids.add(event_id)
-
-        if missing_event_ids:
-            # Now pull out the state groups for any missing events from DB
-            event_to_groups = yield self._get_state_group_for_events(missing_event_ids)
-            event_id_to_state_group.update(event_to_groups)
-
-        # State groups of old_latest_event_ids
-        old_state_groups = set(
-            event_id_to_state_group[evid] for evid in old_latest_event_ids
-        )
-
-        # State groups of new_latest_event_ids
-        new_state_groups = set(
-            event_id_to_state_group[evid] for evid in new_latest_event_ids
-        )
-
-        # If they old and new groups are the same then we don't need to do
-        # anything.
-        if old_state_groups == new_state_groups:
-            return None, None
-
-        if len(new_state_groups) == 1 and len(old_state_groups) == 1:
-            # If we're going from one state group to another, lets check if
-            # we have a delta for that transition. If we do then we can just
-            # return that.
-
-            new_state_group = next(iter(new_state_groups))
-            old_state_group = next(iter(old_state_groups))
-
-            delta_ids = state_group_deltas.get((old_state_group, new_state_group), None)
-            if delta_ids is not None:
-                # We have a delta from the existing to new current state,
-                # so lets just return that. If we happen to already have
-                # the current state in memory then lets also return that,
-                # but it doesn't matter if we don't.
-                new_state = state_groups_map.get(new_state_group)
-                return new_state, delta_ids
-
-        # Now that we have calculated new_state_groups we need to get
-        # their state IDs so we can resolve to a single state set.
-        missing_state = new_state_groups - set(state_groups_map)
-        if missing_state:
-            group_to_state = yield self._get_state_for_groups(missing_state)
-            state_groups_map.update(group_to_state)
-
-        if len(new_state_groups) == 1:
-            # If there is only one state group, then we know what the current
-            # state is.
-            return state_groups_map[new_state_groups.pop()], None
-
-        # Ok, we need to defer to the state handler to resolve our state sets.
-
-        state_groups = {sg: state_groups_map[sg] for sg in new_state_groups}
-
-        events_map = {ev.event_id: ev for ev, _ in events_context}
-
-        # We need to get the room version, which is in the create event.
-        # Normally that'd be in the database, but its also possible that we're
-        # currently trying to persist it.
-        room_version = None
-        for ev, _ in events_context:
-            if ev.type == EventTypes.Create and ev.state_key == "":
-                room_version = ev.content.get("room_version", "1")
-                break
-
-        if not room_version:
-            room_version = yield self.get_room_version(room_id)
-
-        logger.debug("calling resolve_state_groups from preserve_events")
-        res = yield self._state_resolution_handler.resolve_state_groups(
-            room_id,
-            room_version,
-            state_groups,
-            events_map,
-            state_res_store=StateResolutionStore(self),
-        )
-
-        return res.state, None
-
-    @defer.inlineCallbacks
-    def _calculate_state_delta(self, room_id, current_state):
-        """Calculate the new state deltas for a room.
-
-        Assumes that we are only persisting events for one room at a time.
-
-        Returns:
-            tuple[list, dict] (to_delete, to_insert): where to_delete are the
-            type/state_keys to remove from current_state_events and `to_insert`
-            are the updates to current_state_events.
-        """
-        existing_state = yield self.get_current_state_ids(room_id)
-
-        to_delete = [key for key in existing_state if key not in current_state]
-
-        to_insert = {
-            key: ev_id
-            for key, ev_id in iteritems(current_state)
-            if ev_id != existing_state.get(key)
-        }
-
-        return to_delete, to_insert
-
     @log_function
     def _persist_events_txn(
         self,
@@ -1490,6 +932,13 @@ class EventsStore(
 
             self._handle_event_relations(txn, event)
 
+            # Store the labels for this event.
+            labels = event.content.get(EventContentFields.LABELS)
+            if labels:
+                self.insert_labels_for_event_txn(
+                    txn, event.event_id, labels, event.room_id, event.depth
+                )
+
         # Insert into the room_memberships table.
         self._store_room_members_txn(
             txn,
@@ -1683,7 +1132,7 @@ class EventsStore(
                 AND stream_ordering > ?
             """
             txn.execute(sql, (self.stream_ordering_day_ago,))
-            count, = txn.fetchone()
+            (count,) = txn.fetchone()
             return count
 
         ret = yield self.runInteraction("count_messages", _count_messages)
@@ -1704,7 +1153,7 @@ class EventsStore(
             """
 
             txn.execute(sql, (like_clause, self.stream_ordering_day_ago))
-            count, = txn.fetchone()
+            (count,) = txn.fetchone()
             return count
 
         ret = yield self.runInteraction("count_daily_sent_messages", _count_messages)
@@ -1719,7 +1168,7 @@ class EventsStore(
                 AND stream_ordering > ?
             """
             txn.execute(sql, (self.stream_ordering_day_ago,))
-            count, = txn.fetchone()
+            (count,) = txn.fetchone()
             return count
 
         ret = yield self.runInteraction("count_daily_active_rooms", _count)
@@ -2204,7 +1653,7 @@ class EventsStore(
         """,
             (room_id,),
         )
-        min_depth, = txn.fetchone()
+        (min_depth,) = txn.fetchone()
 
         logger.info("[purge] updating room_depth to %d", min_depth)
 
@@ -2396,7 +1845,6 @@ class EventsStore(
             "room_stats_earliest_token",
             "rooms",
             "stream_ordering_to_exterm",
-            "topics",
             "users_in_public_rooms",
             "users_who_share_private_rooms",
             # no useful index, but let's clear them anyway
@@ -2439,12 +1887,11 @@ class EventsStore(
 
         logger.info("[purge] done")
 
-    @defer.inlineCallbacks
-    def is_event_after(self, event_id1, event_id2):
+    async def is_event_after(self, event_id1, event_id2):
         """Returns True if event_id1 is after event_id2 in the stream
         """
-        to_1, so_1 = yield self._get_event_ordering(event_id1)
-        to_2, so_2 = yield self._get_event_ordering(event_id2)
+        to_1, so_1 = await self._get_event_ordering(event_id1)
+        to_2, so_2 = await self._get_event_ordering(event_id2)
         return (to_1, so_1) > (to_2, so_2)
 
     @cachedInlineCallbacks(max_entries=5000)
@@ -2477,6 +1924,33 @@ class EventsStore(
             get_all_updated_current_state_deltas_txn,
         )
 
+    def insert_labels_for_event_txn(
+        self, txn, event_id, labels, room_id, topological_ordering
+    ):
+        """Store the mapping between an event's ID and its labels, with one row per
+        (event_id, label) tuple.
+
+        Args:
+            txn (LoggingTransaction): The transaction to execute.
+            event_id (str): The event's ID.
+            labels (list[str]): A list of text labels.
+            room_id (str): The ID of the room the event was sent to.
+            topological_ordering (int): The position of the event in the room's topology.
+        """
+        return self._simple_insert_many_txn(
+            txn=txn,
+            table="event_labels",
+            values=[
+                {
+                    "event_id": event_id,
+                    "label": label,
+                    "room_id": room_id,
+                    "topological_ordering": topological_ordering,
+                }
+                for label in labels
+            ],
+        )
+
 
 AllNewEventsResult = namedtuple(
     "AllNewEventsResult",
diff --git a/synapse/storage/data_stores/main/events_bg_updates.py b/synapse/storage/data_stores/main/events_bg_updates.py
index 31ea6f917f..51352b9966 100644
--- a/synapse/storage/data_stores/main/events_bg_updates.py
+++ b/synapse/storage/data_stores/main/events_bg_updates.py
@@ -438,7 +438,7 @@ class EventsBackgroundUpdatesStore(BackgroundUpdateStore):
             if not rows:
                 return 0
 
-            upper_event_id, = rows[-1]
+            (upper_event_id,) = rows[-1]
 
             # Update the redactions with the received_ts.
             #
diff --git a/synapse/storage/data_stores/main/group_server.py b/synapse/storage/data_stores/main/group_server.py
index aeae5a2b28..b3a2771f1b 100644
--- a/synapse/storage/data_stores/main/group_server.py
+++ b/synapse/storage/data_stores/main/group_server.py
@@ -249,7 +249,7 @@ class GroupServerStore(SQLBaseStore):
                 WHERE group_id = ? AND category_id = ?
             """
             txn.execute(sql, (group_id, category_id))
-            order, = txn.fetchone()
+            (order,) = txn.fetchone()
 
         if existing:
             to_update = {}
@@ -509,7 +509,7 @@ class GroupServerStore(SQLBaseStore):
                 WHERE group_id = ? AND role_id = ?
             """
             txn.execute(sql, (group_id, role_id))
-            order, = txn.fetchone()
+            (order,) = txn.fetchone()
 
         if existing:
             to_update = {}
diff --git a/synapse/storage/data_stores/main/monthly_active_users.py b/synapse/storage/data_stores/main/monthly_active_users.py
index e6ee1e4aaa..b41c3d317a 100644
--- a/synapse/storage/data_stores/main/monthly_active_users.py
+++ b/synapse/storage/data_stores/main/monthly_active_users.py
@@ -171,7 +171,7 @@ class MonthlyActiveUsersStore(SQLBaseStore):
             sql = "SELECT COALESCE(count(*), 0) FROM monthly_active_users"
 
             txn.execute(sql)
-            count, = txn.fetchone()
+            (count,) = txn.fetchone()
             return count
 
         return self.runInteraction("count_users", _count_users)
diff --git a/synapse/storage/data_stores/main/push_rule.py b/synapse/storage/data_stores/main/push_rule.py
index cd95f1ce60..b520062d84 100644
--- a/synapse/storage/data_stores/main/push_rule.py
+++ b/synapse/storage/data_stores/main/push_rule.py
@@ -143,7 +143,7 @@ class PushRulesWorkerStore(
                     " WHERE user_id = ? AND ? < stream_id"
                 )
                 txn.execute(sql, (user_id, last_id))
-                count, = txn.fetchone()
+                (count,) = txn.fetchone()
                 return bool(count)
 
             return self.runInteraction(
diff --git a/synapse/storage/data_stores/main/pusher.py b/synapse/storage/data_stores/main/pusher.py
index f005c1ae0a..d76861cdc0 100644
--- a/synapse/storage/data_stores/main/pusher.py
+++ b/synapse/storage/data_stores/main/pusher.py
@@ -44,7 +44,7 @@ class PusherWorkerStore(SQLBaseStore):
 
                 r["data"] = json.loads(dataJson)
             except Exception as e:
-                logger.warn(
+                logger.warning(
                     "Invalid JSON in data for pusher %d: %s, %s",
                     r["id"],
                     dataJson,
diff --git a/synapse/storage/data_stores/main/registration.py b/synapse/storage/data_stores/main/registration.py
index 6c5b29288a..f70d41ecab 100644
--- a/synapse/storage/data_stores/main/registration.py
+++ b/synapse/storage/data_stores/main/registration.py
@@ -459,7 +459,7 @@ class RegistrationWorkerStore(SQLBaseStore):
                 WHERE appservice_id IS NULL
             """
             )
-            count, = txn.fetchone()
+            (count,) = txn.fetchone()
             return count
 
         ret = yield self.runInteraction("count_users", _count_users)
diff --git a/synapse/storage/data_stores/main/roommember.py b/synapse/storage/data_stores/main/roommember.py
index e47ab604dd..2af24a20b7 100644
--- a/synapse/storage/data_stores/main/roommember.py
+++ b/synapse/storage/data_stores/main/roommember.py
@@ -720,7 +720,7 @@ class RoomMemberWorkerStore(EventsWorkerStore):
         # See bulk_get_push_rules_for_room for how we work around this.
         assert state_group is not None
 
-        cache = self._get_joined_hosts_cache(room_id)
+        cache = yield self._get_joined_hosts_cache(room_id)
         joined_hosts = yield cache.get_destinations(state_entry)
 
         return joined_hosts
@@ -927,7 +927,7 @@ class RoomMemberBackgroundUpdateStore(BackgroundUpdateStore):
                 if not row or not row[0]:
                     return processed, True
 
-                next_room, = row
+                (next_room,) = row
 
                 sql = """
                     UPDATE current_state_events
diff --git a/synapse/storage/data_stores/main/schema/delta/56/delete_keys_from_deleted_backups.sql b/synapse/storage/data_stores/main/schema/delta/56/delete_keys_from_deleted_backups.sql
new file mode 100644
index 0000000000..1d2ddb1b1a
--- /dev/null
+++ b/synapse/storage/data_stores/main/schema/delta/56/delete_keys_from_deleted_backups.sql
@@ -0,0 +1,25 @@
+/* Copyright 2019 The Matrix.org Foundation C.I.C
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/* delete room keys that belong to deleted room key version, or to room key
+ * versions that don't exist (anymore)
+ */
+DELETE FROM e2e_room_keys
+WHERE version NOT IN (
+  SELECT version
+  FROM e2e_room_keys_versions
+  WHERE e2e_room_keys.user_id = e2e_room_keys_versions.user_id
+  AND e2e_room_keys_versions.deleted = 0
+);
diff --git a/synapse/storage/data_stores/main/schema/delta/56/event_labels.sql b/synapse/storage/data_stores/main/schema/delta/56/event_labels.sql
new file mode 100644
index 0000000000..5e29c1da19
--- /dev/null
+++ b/synapse/storage/data_stores/main/schema/delta/56/event_labels.sql
@@ -0,0 +1,30 @@
+/* Copyright 2019 The Matrix.org Foundation C.I.C.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+-- room_id and topoligical_ordering are denormalised from the events table in order to
+-- make the index work.
+CREATE TABLE IF NOT EXISTS event_labels (
+    event_id TEXT,
+    label TEXT,
+    room_id TEXT NOT NULL,
+    topological_ordering BIGINT NOT NULL,
+    PRIMARY KEY(event_id, label)
+);
+
+
+-- This index enables an event pagination looking for a particular label to index the
+-- event_labels table first, which is much quicker than scanning the events table and then
+-- filtering by label, if the label is rarely used relative to the size of the room.
+CREATE INDEX event_labels_room_id_label_idx ON event_labels(room_id, label, topological_ordering);
diff --git a/synapse/storage/data_stores/main/schema/delta/56/hidden_devices_fix.sql.sqlite b/synapse/storage/data_stores/main/schema/delta/56/hidden_devices_fix.sql.sqlite
new file mode 100644
index 0000000000..e8b1fd35d8
--- /dev/null
+++ b/synapse/storage/data_stores/main/schema/delta/56/hidden_devices_fix.sql.sqlite
@@ -0,0 +1,42 @@
+/* Copyright 2019 The Matrix.org Foundation C.I.C.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/* Change the hidden column from a default value of FALSE to a default value of
+ * 0, because sqlite3 prior to 3.23.0 caused the hidden column to contain the
+ * string 'FALSE', which is truthy.
+ *
+ * Since sqlite doesn't allow us to just change the default value, we have to
+ * recreate the table, copy the data, fix the rows that have incorrect data, and
+ * replace the old table with the new table.
+ */
+
+CREATE TABLE IF NOT EXISTS devices2 (
+    user_id TEXT NOT NULL,
+    device_id TEXT NOT NULL,
+    display_name TEXT,
+    last_seen BIGINT,
+    ip TEXT,
+    user_agent TEXT,
+    hidden BOOLEAN DEFAULT 0,
+    CONSTRAINT device_uniqueness UNIQUE (user_id, device_id)
+);
+
+INSERT INTO devices2 SELECT * FROM devices;
+
+UPDATE devices2 SET hidden = 0 WHERE hidden = 'FALSE';
+
+DROP TABLE devices;
+
+ALTER TABLE devices2 RENAME TO devices;
diff --git a/synapse/storage/data_stores/main/search.py b/synapse/storage/data_stores/main/search.py
index 0e08497452..d1d7c6863d 100644
--- a/synapse/storage/data_stores/main/search.py
+++ b/synapse/storage/data_stores/main/search.py
@@ -196,7 +196,7 @@ class SearchBackgroundUpdateStore(BackgroundUpdateStore):
                         " ON event_search USING GIN (vector)"
                     )
                 except psycopg2.ProgrammingError as e:
-                    logger.warn(
+                    logger.warning(
                         "Ignoring error %r when trying to switch from GIST to GIN", e
                     )
 
@@ -672,7 +672,7 @@ class SearchStore(SearchBackgroundUpdateStore):
                     )
                 )
                 txn.execute(query, (value, search_query))
-                headline, = txn.fetchall()[0]
+                (headline,) = txn.fetchall()[0]
 
                 # Now we need to pick the possible highlights out of the haedline
                 # result.
diff --git a/synapse/storage/data_stores/main/state.py b/synapse/storage/data_stores/main/state.py
index d54442e5fa..9e1541988e 100644
--- a/synapse/storage/data_stores/main/state.py
+++ b/synapse/storage/data_stores/main/state.py
@@ -15,6 +15,7 @@
 
 import logging
 from collections import namedtuple
+from typing import Iterable, Tuple
 
 from six import iteritems, itervalues
 from six.moves import range
@@ -23,6 +24,8 @@ from twisted.internet import defer
 
 from synapse.api.constants import EventTypes
 from synapse.api.errors import NotFoundError
+from synapse.events import EventBase
+from synapse.events.snapshot import EventContext
 from synapse.storage._base import SQLBaseStore
 from synapse.storage.background_updates import BackgroundUpdateStore
 from synapse.storage.data_stores.main.events_worker import EventsWorkerStore
@@ -722,16 +725,18 @@ class StateGroupWorkerStore(
         member_filter, non_member_filter = state_filter.get_member_split()
 
         # Now we look them up in the member and non-member caches
-        non_member_state, incomplete_groups_nm, = (
-            yield self._get_state_for_groups_using_cache(
-                groups, self._state_group_cache, state_filter=non_member_filter
-            )
+        (
+            non_member_state,
+            incomplete_groups_nm,
+        ) = yield self._get_state_for_groups_using_cache(
+            groups, self._state_group_cache, state_filter=non_member_filter
         )
 
-        member_state, incomplete_groups_m, = (
-            yield self._get_state_for_groups_using_cache(
-                groups, self._state_group_members_cache, state_filter=member_filter
-            )
+        (
+            member_state,
+            incomplete_groups_m,
+        ) = yield self._get_state_for_groups_using_cache(
+            groups, self._state_group_members_cache, state_filter=member_filter
         )
 
         state = dict(non_member_state)
@@ -1073,7 +1078,7 @@ class StateBackgroundUpdateStore(
                     " WHERE id < ? AND room_id = ?",
                     (state_group, room_id),
                 )
-                prev_group, = txn.fetchone()
+                (prev_group,) = txn.fetchone()
                 new_last_state_group = state_group
 
                 if prev_group:
@@ -1215,7 +1220,9 @@ class StateStore(StateGroupWorkerStore, StateBackgroundUpdateStore):
     def __init__(self, db_conn, hs):
         super(StateStore, self).__init__(db_conn, hs)
 
-    def _store_event_state_mappings_txn(self, txn, events_and_contexts):
+    def _store_event_state_mappings_txn(
+        self, txn, events_and_contexts: Iterable[Tuple[EventBase, EventContext]]
+    ):
         state_groups = {}
         for event, context in events_and_contexts:
             if event.internal_metadata.is_outlier():
@@ -1224,7 +1231,7 @@ class StateStore(StateGroupWorkerStore, StateBackgroundUpdateStore):
             # if the event was rejected, just give it the same state as its
             # predecessor.
             if context.rejected:
-                state_groups[event.event_id] = context.prev_group
+                state_groups[event.event_id] = context.state_group_before_event
                 continue
 
             state_groups[event.event_id] = context.state_group
diff --git a/synapse/storage/data_stores/main/stats.py b/synapse/storage/data_stores/main/stats.py
index 5ab639b2ad..45b3de7d56 100644
--- a/synapse/storage/data_stores/main/stats.py
+++ b/synapse/storage/data_stores/main/stats.py
@@ -332,7 +332,7 @@ class StatsStore(StateDeltasStore):
         def _bulk_update_stats_delta_txn(txn):
             for stats_type, stats_updates in updates.items():
                 for stats_id, fields in stats_updates.items():
-                    logger.info(
+                    logger.debug(
                         "Updating %s stats for %s: %s", stats_type, stats_id, fields
                     )
                     self._update_stats_delta_txn(
@@ -773,7 +773,7 @@ class StatsStore(StateDeltasStore):
                 (room_id,),
             )
 
-            current_state_events_count, = txn.fetchone()
+            (current_state_events_count,) = txn.fetchone()
 
             users_in_room = self.get_users_in_room_txn(txn, room_id)
 
@@ -863,7 +863,7 @@ class StatsStore(StateDeltasStore):
                 """,
                 (user_id,),
             )
-            count, = txn.fetchone()
+            (count,) = txn.fetchone()
             return count, pos
 
         joined_rooms, pos = yield self.runInteraction(
diff --git a/synapse/storage/data_stores/main/stream.py b/synapse/storage/data_stores/main/stream.py
index 263999dfca..616ef91d4e 100644
--- a/synapse/storage/data_stores/main/stream.py
+++ b/synapse/storage/data_stores/main/stream.py
@@ -229,6 +229,14 @@ def filter_to_clause(event_filter):
         clauses.append("contains_url = ?")
         args.append(event_filter.contains_url)
 
+    # We're only applying the "labels" filter on the database query, because applying the
+    # "not_labels" filter via a SQL query is non-trivial. Instead, we let
+    # event_filter.check_fields apply it, which is not as efficient but makes the
+    # implementation simpler.
+    if event_filter.labels:
+        clauses.append("(%s)" % " OR ".join("label = ?" for _ in event_filter.labels))
+        args.extend(event_filter.labels)
+
     return " AND ".join(clauses), args
 
 
@@ -864,8 +872,9 @@ class StreamWorkerStore(EventsWorkerStore, SQLBaseStore):
         args.append(int(limit))
 
         sql = (
-            "SELECT event_id, topological_ordering, stream_ordering"
+            "SELECT DISTINCT event_id, topological_ordering, stream_ordering"
             " FROM events"
+            " LEFT JOIN event_labels USING (event_id, room_id, topological_ordering)"
             " WHERE outlier = ? AND room_id = ? AND %(bounds)s"
             " ORDER BY topological_ordering %(order)s,"
             " stream_ordering %(order)s LIMIT ?"
diff --git a/synapse/storage/persist_events.py b/synapse/storage/persist_events.py
new file mode 100644
index 0000000000..fa03ca9ff7
--- /dev/null
+++ b/synapse/storage/persist_events.py
@@ -0,0 +1,649 @@
+# -*- coding: utf-8 -*-
+# Copyright 2014-2016 OpenMarket Ltd
+# Copyright 2018-2019 New Vector Ltd
+# Copyright 2019 The Matrix.org Foundation C.I.C.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import logging
+from collections import deque, namedtuple
+
+from six import iteritems
+from six.moves import range
+
+from prometheus_client import Counter, Histogram
+
+from twisted.internet import defer
+
+from synapse.api.constants import EventTypes
+from synapse.logging.context import PreserveLoggingContext, make_deferred_yieldable
+from synapse.metrics.background_process_metrics import run_as_background_process
+from synapse.state import StateResolutionStore
+from synapse.storage.data_stores import DataStores
+from synapse.util.async_helpers import ObservableDeferred
+from synapse.util.metrics import Measure
+
+logger = logging.getLogger(__name__)
+
+# The number of times we are recalculating the current state
+state_delta_counter = Counter("synapse_storage_events_state_delta", "")
+
+# The number of times we are recalculating state when there is only a
+# single forward extremity
+state_delta_single_event_counter = Counter(
+    "synapse_storage_events_state_delta_single_event", ""
+)
+
+# The number of times we are reculating state when we could have resonably
+# calculated the delta when we calculated the state for an event we were
+# persisting.
+state_delta_reuse_delta_counter = Counter(
+    "synapse_storage_events_state_delta_reuse_delta", ""
+)
+
+# The number of forward extremities for each new event.
+forward_extremities_counter = Histogram(
+    "synapse_storage_events_forward_extremities_persisted",
+    "Number of forward extremities for each new event",
+    buckets=(1, 2, 3, 5, 7, 10, 15, 20, 50, 100, 200, 500, "+Inf"),
+)
+
+# The number of stale forward extremities for each new event. Stale extremities
+# are those that were in the previous set of extremities as well as the new.
+stale_forward_extremities_counter = Histogram(
+    "synapse_storage_events_stale_forward_extremities_persisted",
+    "Number of unchanged forward extremities for each new event",
+    buckets=(0, 1, 2, 3, 5, 7, 10, 15, 20, 50, 100, 200, 500, "+Inf"),
+)
+
+
+class _EventPeristenceQueue(object):
+    """Queues up events so that they can be persisted in bulk with only one
+    concurrent transaction per room.
+    """
+
+    _EventPersistQueueItem = namedtuple(
+        "_EventPersistQueueItem", ("events_and_contexts", "backfilled", "deferred")
+    )
+
+    def __init__(self):
+        self._event_persist_queues = {}
+        self._currently_persisting_rooms = set()
+
+    def add_to_queue(self, room_id, events_and_contexts, backfilled):
+        """Add events to the queue, with the given persist_event options.
+
+        NB: due to the normal usage pattern of this method, it does *not*
+        follow the synapse logcontext rules, and leaves the logcontext in
+        place whether or not the returned deferred is ready.
+
+        Args:
+            room_id (str):
+            events_and_contexts (list[(EventBase, EventContext)]):
+            backfilled (bool):
+
+        Returns:
+            defer.Deferred: a deferred which will resolve once the events are
+                persisted. Runs its callbacks *without* a logcontext.
+        """
+        queue = self._event_persist_queues.setdefault(room_id, deque())
+        if queue:
+            # if the last item in the queue has the same `backfilled` setting,
+            # we can just add these new events to that item.
+            end_item = queue[-1]
+            if end_item.backfilled == backfilled:
+                end_item.events_and_contexts.extend(events_and_contexts)
+                return end_item.deferred.observe()
+
+        deferred = ObservableDeferred(defer.Deferred(), consumeErrors=True)
+
+        queue.append(
+            self._EventPersistQueueItem(
+                events_and_contexts=events_and_contexts,
+                backfilled=backfilled,
+                deferred=deferred,
+            )
+        )
+
+        return deferred.observe()
+
+    def handle_queue(self, room_id, per_item_callback):
+        """Attempts to handle the queue for a room if not already being handled.
+
+        The given callback will be invoked with for each item in the queue,
+        of type _EventPersistQueueItem. The per_item_callback will continuously
+        be called with new items, unless the queue becomnes empty. The return
+        value of the function will be given to the deferreds waiting on the item,
+        exceptions will be passed to the deferreds as well.
+
+        This function should therefore be called whenever anything is added
+        to the queue.
+
+        If another callback is currently handling the queue then it will not be
+        invoked.
+        """
+
+        if room_id in self._currently_persisting_rooms:
+            return
+
+        self._currently_persisting_rooms.add(room_id)
+
+        @defer.inlineCallbacks
+        def handle_queue_loop():
+            try:
+                queue = self._get_drainining_queue(room_id)
+                for item in queue:
+                    try:
+                        ret = yield per_item_callback(item)
+                    except Exception:
+                        with PreserveLoggingContext():
+                            item.deferred.errback()
+                    else:
+                        with PreserveLoggingContext():
+                            item.deferred.callback(ret)
+            finally:
+                queue = self._event_persist_queues.pop(room_id, None)
+                if queue:
+                    self._event_persist_queues[room_id] = queue
+                self._currently_persisting_rooms.discard(room_id)
+
+        # set handle_queue_loop off in the background
+        run_as_background_process("persist_events", handle_queue_loop)
+
+    def _get_drainining_queue(self, room_id):
+        queue = self._event_persist_queues.setdefault(room_id, deque())
+
+        try:
+            while True:
+                yield queue.popleft()
+        except IndexError:
+            # Queue has been drained.
+            pass
+
+
+class EventsPersistenceStorage(object):
+    """High level interface for handling persisting newly received events.
+
+    Takes care of batching up events by room, and calculating the necessary
+    current state and forward extremity changes.
+    """
+
+    def __init__(self, hs, stores: DataStores):
+        # We ultimately want to split out the state store from the main store,
+        # so we use separate variables here even though they point to the same
+        # store for now.
+        self.main_store = stores.main
+        self.state_store = stores.main
+
+        self._clock = hs.get_clock()
+        self.is_mine_id = hs.is_mine_id
+        self._event_persist_queue = _EventPeristenceQueue()
+        self._state_resolution_handler = hs.get_state_resolution_handler()
+
+    @defer.inlineCallbacks
+    def persist_events(self, events_and_contexts, backfilled=False):
+        """
+        Write events to the database
+        Args:
+            events_and_contexts: list of tuples of (event, context)
+            backfilled (bool): Whether the results are retrieved from federation
+                via backfill or not. Used to determine if they're "new" events
+                which might update the current state etc.
+
+        Returns:
+            Deferred[int]: the stream ordering of the latest persisted event
+        """
+        partitioned = {}
+        for event, ctx in events_and_contexts:
+            partitioned.setdefault(event.room_id, []).append((event, ctx))
+
+        deferreds = []
+        for room_id, evs_ctxs in iteritems(partitioned):
+            d = self._event_persist_queue.add_to_queue(
+                room_id, evs_ctxs, backfilled=backfilled
+            )
+            deferreds.append(d)
+
+        for room_id in partitioned:
+            self._maybe_start_persisting(room_id)
+
+        yield make_deferred_yieldable(
+            defer.gatherResults(deferreds, consumeErrors=True)
+        )
+
+        max_persisted_id = yield self.main_store.get_current_events_token()
+
+        return max_persisted_id
+
+    @defer.inlineCallbacks
+    def persist_event(self, event, context, backfilled=False):
+        """
+
+        Args:
+            event (EventBase):
+            context (EventContext):
+            backfilled (bool):
+
+        Returns:
+            Deferred: resolves to (int, int): the stream ordering of ``event``,
+            and the stream ordering of the latest persisted event
+        """
+        deferred = self._event_persist_queue.add_to_queue(
+            event.room_id, [(event, context)], backfilled=backfilled
+        )
+
+        self._maybe_start_persisting(event.room_id)
+
+        yield make_deferred_yieldable(deferred)
+
+        max_persisted_id = yield self.main_store.get_current_events_token()
+        return (event.internal_metadata.stream_ordering, max_persisted_id)
+
+    def _maybe_start_persisting(self, room_id):
+        @defer.inlineCallbacks
+        def persisting_queue(item):
+            with Measure(self._clock, "persist_events"):
+                yield self._persist_events(
+                    item.events_and_contexts, backfilled=item.backfilled
+                )
+
+        self._event_persist_queue.handle_queue(room_id, persisting_queue)
+
+    @defer.inlineCallbacks
+    def _persist_events(self, events_and_contexts, backfilled=False):
+        """Calculates the change to current state and forward extremities, and
+        persists the given events and with those updates.
+
+        Args:
+            events_and_contexts (list[(EventBase, EventContext)]):
+            backfilled (bool):
+            delete_existing (bool):
+
+        Returns:
+            Deferred: resolves when the events have been persisted
+        """
+        if not events_and_contexts:
+            return
+
+        chunks = [
+            events_and_contexts[x : x + 100]
+            for x in range(0, len(events_and_contexts), 100)
+        ]
+
+        for chunk in chunks:
+            # We can't easily parallelize these since different chunks
+            # might contain the same event. :(
+
+            # NB: Assumes that we are only persisting events for one room
+            # at a time.
+
+            # map room_id->list[event_ids] giving the new forward
+            # extremities in each room
+            new_forward_extremeties = {}
+
+            # map room_id->(type,state_key)->event_id tracking the full
+            # state in each room after adding these events.
+            # This is simply used to prefill the get_current_state_ids
+            # cache
+            current_state_for_room = {}
+
+            # map room_id->(to_delete, to_insert) where to_delete is a list
+            # of type/state keys to remove from current state, and to_insert
+            # is a map (type,key)->event_id giving the state delta in each
+            # room
+            state_delta_for_room = {}
+
+            if not backfilled:
+                with Measure(self._clock, "_calculate_state_and_extrem"):
+                    # Work out the new "current state" for each room.
+                    # We do this by working out what the new extremities are and then
+                    # calculating the state from that.
+                    events_by_room = {}
+                    for event, context in chunk:
+                        events_by_room.setdefault(event.room_id, []).append(
+                            (event, context)
+                        )
+
+                    for room_id, ev_ctx_rm in iteritems(events_by_room):
+                        latest_event_ids = yield self.main_store.get_latest_event_ids_in_room(
+                            room_id
+                        )
+                        new_latest_event_ids = yield self._calculate_new_extremities(
+                            room_id, ev_ctx_rm, latest_event_ids
+                        )
+
+                        latest_event_ids = set(latest_event_ids)
+                        if new_latest_event_ids == latest_event_ids:
+                            # No change in extremities, so no change in state
+                            continue
+
+                        # there should always be at least one forward extremity.
+                        # (except during the initial persistence of the send_join
+                        # results, in which case there will be no existing
+                        # extremities, so we'll `continue` above and skip this bit.)
+                        assert new_latest_event_ids, "No forward extremities left!"
+
+                        new_forward_extremeties[room_id] = new_latest_event_ids
+
+                        len_1 = (
+                            len(latest_event_ids) == 1
+                            and len(new_latest_event_ids) == 1
+                        )
+                        if len_1:
+                            all_single_prev_not_state = all(
+                                len(event.prev_event_ids()) == 1
+                                and not event.is_state()
+                                for event, ctx in ev_ctx_rm
+                            )
+                            # Don't bother calculating state if they're just
+                            # a long chain of single ancestor non-state events.
+                            if all_single_prev_not_state:
+                                continue
+
+                        state_delta_counter.inc()
+                        if len(new_latest_event_ids) == 1:
+                            state_delta_single_event_counter.inc()
+
+                            # This is a fairly handwavey check to see if we could
+                            # have guessed what the delta would have been when
+                            # processing one of these events.
+                            # What we're interested in is if the latest extremities
+                            # were the same when we created the event as they are
+                            # now. When this server creates a new event (as opposed
+                            # to receiving it over federation) it will use the
+                            # forward extremities as the prev_events, so we can
+                            # guess this by looking at the prev_events and checking
+                            # if they match the current forward extremities.
+                            for ev, _ in ev_ctx_rm:
+                                prev_event_ids = set(ev.prev_event_ids())
+                                if latest_event_ids == prev_event_ids:
+                                    state_delta_reuse_delta_counter.inc()
+                                    break
+
+                        logger.info("Calculating state delta for room %s", room_id)
+                        with Measure(
+                            self._clock, "persist_events.get_new_state_after_events"
+                        ):
+                            res = yield self._get_new_state_after_events(
+                                room_id,
+                                ev_ctx_rm,
+                                latest_event_ids,
+                                new_latest_event_ids,
+                            )
+                            current_state, delta_ids = res
+
+                        # If either are not None then there has been a change,
+                        # and we need to work out the delta (or use that
+                        # given)
+                        if delta_ids is not None:
+                            # If there is a delta we know that we've
+                            # only added or replaced state, never
+                            # removed keys entirely.
+                            state_delta_for_room[room_id] = ([], delta_ids)
+                        elif current_state is not None:
+                            with Measure(
+                                self._clock, "persist_events.calculate_state_delta"
+                            ):
+                                delta = yield self._calculate_state_delta(
+                                    room_id, current_state
+                                )
+                            state_delta_for_room[room_id] = delta
+
+                        # If we have the current_state then lets prefill
+                        # the cache with it.
+                        if current_state is not None:
+                            current_state_for_room[room_id] = current_state
+
+            yield self.main_store._persist_events_and_state_updates(
+                chunk,
+                current_state_for_room=current_state_for_room,
+                state_delta_for_room=state_delta_for_room,
+                new_forward_extremeties=new_forward_extremeties,
+                backfilled=backfilled,
+            )
+
+    @defer.inlineCallbacks
+    def _calculate_new_extremities(self, room_id, event_contexts, latest_event_ids):
+        """Calculates the new forward extremities for a room given events to
+        persist.
+
+        Assumes that we are only persisting events for one room at a time.
+        """
+
+        # we're only interested in new events which aren't outliers and which aren't
+        # being rejected.
+        new_events = [
+            event
+            for event, ctx in event_contexts
+            if not event.internal_metadata.is_outlier()
+            and not ctx.rejected
+            and not event.internal_metadata.is_soft_failed()
+        ]
+
+        latest_event_ids = set(latest_event_ids)
+
+        # start with the existing forward extremities
+        result = set(latest_event_ids)
+
+        # add all the new events to the list
+        result.update(event.event_id for event in new_events)
+
+        # Now remove all events which are prev_events of any of the new events
+        result.difference_update(
+            e_id for event in new_events for e_id in event.prev_event_ids()
+        )
+
+        # Remove any events which are prev_events of any existing events.
+        existing_prevs = yield self.main_store._get_events_which_are_prevs(result)
+        result.difference_update(existing_prevs)
+
+        # Finally handle the case where the new events have soft-failed prev
+        # events. If they do we need to remove them and their prev events,
+        # otherwise we end up with dangling extremities.
+        existing_prevs = yield self.main_store._get_prevs_before_rejected(
+            e_id for event in new_events for e_id in event.prev_event_ids()
+        )
+        result.difference_update(existing_prevs)
+
+        # We only update metrics for events that change forward extremities
+        # (e.g. we ignore backfill/outliers/etc)
+        if result != latest_event_ids:
+            forward_extremities_counter.observe(len(result))
+            stale = latest_event_ids & result
+            stale_forward_extremities_counter.observe(len(stale))
+
+        return result
+
+    @defer.inlineCallbacks
+    def _get_new_state_after_events(
+        self, room_id, events_context, old_latest_event_ids, new_latest_event_ids
+    ):
+        """Calculate the current state dict after adding some new events to
+        a room
+
+        Args:
+            room_id (str):
+                room to which the events are being added. Used for logging etc
+
+            events_context (list[(EventBase, EventContext)]):
+                events and contexts which are being added to the room
+
+            old_latest_event_ids (iterable[str]):
+                the old forward extremities for the room.
+
+            new_latest_event_ids (iterable[str]):
+                the new forward extremities for the room.
+
+        Returns:
+            Deferred[tuple[dict[(str,str), str]|None, dict[(str,str), str]|None]]:
+            Returns a tuple of two state maps, the first being the full new current
+            state and the second being the delta to the existing current state.
+            If both are None then there has been no change.
+
+            If there has been a change then we only return the delta if its
+            already been calculated. Conversely if we do know the delta then
+            the new current state is only returned if we've already calculated
+            it.
+        """
+        # map from state_group to ((type, key) -> event_id) state map
+        state_groups_map = {}
+
+        # Map from (prev state group, new state group) -> delta state dict
+        state_group_deltas = {}
+
+        for ev, ctx in events_context:
+            if ctx.state_group is None:
+                # This should only happen for outlier events.
+                if not ev.internal_metadata.is_outlier():
+                    raise Exception(
+                        "Context for new event %s has no state "
+                        "group" % (ev.event_id,)
+                    )
+                continue
+
+            if ctx.state_group in state_groups_map:
+                continue
+
+            # We're only interested in pulling out state that has already
+            # been cached in the context. We'll pull stuff out of the DB later
+            # if necessary.
+            current_state_ids = ctx.get_cached_current_state_ids()
+            if current_state_ids is not None:
+                state_groups_map[ctx.state_group] = current_state_ids
+
+            if ctx.prev_group:
+                state_group_deltas[(ctx.prev_group, ctx.state_group)] = ctx.delta_ids
+
+        # We need to map the event_ids to their state groups. First, let's
+        # check if the event is one we're persisting, in which case we can
+        # pull the state group from its context.
+        # Otherwise we need to pull the state group from the database.
+
+        # Set of events we need to fetch groups for. (We know none of the old
+        # extremities are going to be in events_context).
+        missing_event_ids = set(old_latest_event_ids)
+
+        event_id_to_state_group = {}
+        for event_id in new_latest_event_ids:
+            # First search in the list of new events we're adding.
+            for ev, ctx in events_context:
+                if event_id == ev.event_id and ctx.state_group is not None:
+                    event_id_to_state_group[event_id] = ctx.state_group
+                    break
+            else:
+                # If we couldn't find it, then we'll need to pull
+                # the state from the database
+                missing_event_ids.add(event_id)
+
+        if missing_event_ids:
+            # Now pull out the state groups for any missing events from DB
+            event_to_groups = yield self.main_store._get_state_group_for_events(
+                missing_event_ids
+            )
+            event_id_to_state_group.update(event_to_groups)
+
+        # State groups of old_latest_event_ids
+        old_state_groups = set(
+            event_id_to_state_group[evid] for evid in old_latest_event_ids
+        )
+
+        # State groups of new_latest_event_ids
+        new_state_groups = set(
+            event_id_to_state_group[evid] for evid in new_latest_event_ids
+        )
+
+        # If they old and new groups are the same then we don't need to do
+        # anything.
+        if old_state_groups == new_state_groups:
+            return None, None
+
+        if len(new_state_groups) == 1 and len(old_state_groups) == 1:
+            # If we're going from one state group to another, lets check if
+            # we have a delta for that transition. If we do then we can just
+            # return that.
+
+            new_state_group = next(iter(new_state_groups))
+            old_state_group = next(iter(old_state_groups))
+
+            delta_ids = state_group_deltas.get((old_state_group, new_state_group), None)
+            if delta_ids is not None:
+                # We have a delta from the existing to new current state,
+                # so lets just return that. If we happen to already have
+                # the current state in memory then lets also return that,
+                # but it doesn't matter if we don't.
+                new_state = state_groups_map.get(new_state_group)
+                return new_state, delta_ids
+
+        # Now that we have calculated new_state_groups we need to get
+        # their state IDs so we can resolve to a single state set.
+        missing_state = new_state_groups - set(state_groups_map)
+        if missing_state:
+            group_to_state = yield self.state_store._get_state_for_groups(missing_state)
+            state_groups_map.update(group_to_state)
+
+        if len(new_state_groups) == 1:
+            # If there is only one state group, then we know what the current
+            # state is.
+            return state_groups_map[new_state_groups.pop()], None
+
+        # Ok, we need to defer to the state handler to resolve our state sets.
+
+        state_groups = {sg: state_groups_map[sg] for sg in new_state_groups}
+
+        events_map = {ev.event_id: ev for ev, _ in events_context}
+
+        # We need to get the room version, which is in the create event.
+        # Normally that'd be in the database, but its also possible that we're
+        # currently trying to persist it.
+        room_version = None
+        for ev, _ in events_context:
+            if ev.type == EventTypes.Create and ev.state_key == "":
+                room_version = ev.content.get("room_version", "1")
+                break
+
+        if not room_version:
+            room_version = yield self.main_store.get_room_version(room_id)
+
+        logger.debug("calling resolve_state_groups from preserve_events")
+        res = yield self._state_resolution_handler.resolve_state_groups(
+            room_id,
+            room_version,
+            state_groups,
+            events_map,
+            state_res_store=StateResolutionStore(self.main_store),
+        )
+
+        return res.state, None
+
+    @defer.inlineCallbacks
+    def _calculate_state_delta(self, room_id, current_state):
+        """Calculate the new state deltas for a room.
+
+        Assumes that we are only persisting events for one room at a time.
+
+        Returns:
+            tuple[list, dict] (to_delete, to_insert): where to_delete are the
+            type/state_keys to remove from current_state_events and `to_insert`
+            are the updates to current_state_events.
+        """
+        existing_state = yield self.main_store.get_current_state_ids(room_id)
+
+        to_delete = [key for key in existing_state if key not in current_state]
+
+        to_insert = {
+            key: ev_id
+            for key, ev_id in iteritems(current_state)
+            if ev_id != existing_state.get(key)
+        }
+
+        return to_delete, to_insert
diff --git a/synapse/storage/state.py b/synapse/storage/state.py
index a2df8fa827..3735846899 100644
--- a/synapse/storage/state.py
+++ b/synapse/storage/state.py
@@ -19,6 +19,8 @@ from six import iteritems, itervalues
 
 import attr
 
+from twisted.internet import defer
+
 from synapse.api.constants import EventTypes
 
 logger = logging.getLogger(__name__)
@@ -322,3 +324,234 @@ class StateFilter(object):
         )
 
         return member_filter, non_member_filter
+
+
+class StateGroupStorage(object):
+    """High level interface to fetching state for event.
+    """
+
+    def __init__(self, hs, stores):
+        self.stores = stores
+
+    def get_state_group_delta(self, state_group):
+        """Given a state group try to return a previous group and a delta between
+        the old and the new.
+
+        Returns:
+            Deferred[Tuple[Optional[int], Optional[list[dict[tuple[str, str], str]]]]]):
+                (prev_group, delta_ids)
+        """
+
+        return self.stores.main.get_state_group_delta(state_group)
+
+    @defer.inlineCallbacks
+    def get_state_groups_ids(self, _room_id, event_ids):
+        """Get the event IDs of all the state for the state groups for the given events
+
+        Args:
+            _room_id (str): id of the room for these events
+            event_ids (iterable[str]): ids of the events
+
+        Returns:
+            Deferred[dict[int, dict[tuple[str, str], str]]]:
+                dict of state_group_id -> (dict of (type, state_key) -> event id)
+        """
+        if not event_ids:
+            return {}
+
+        event_to_groups = yield self.stores.main._get_state_group_for_events(event_ids)
+
+        groups = set(itervalues(event_to_groups))
+        group_to_state = yield self.stores.main._get_state_for_groups(groups)
+
+        return group_to_state
+
+    @defer.inlineCallbacks
+    def get_state_ids_for_group(self, state_group):
+        """Get the event IDs of all the state in the given state group
+
+        Args:
+            state_group (int)
+
+        Returns:
+            Deferred[dict]: Resolves to a map of (type, state_key) -> event_id
+        """
+        group_to_state = yield self._get_state_for_groups((state_group,))
+
+        return group_to_state[state_group]
+
+    @defer.inlineCallbacks
+    def get_state_groups(self, room_id, event_ids):
+        """ Get the state groups for the given list of event_ids
+        Returns:
+            Deferred[dict[int, list[EventBase]]]:
+                dict of state_group_id -> list of state events.
+        """
+        if not event_ids:
+            return {}
+
+        group_to_ids = yield self.get_state_groups_ids(room_id, event_ids)
+
+        state_event_map = yield self.stores.main.get_events(
+            [
+                ev_id
+                for group_ids in itervalues(group_to_ids)
+                for ev_id in itervalues(group_ids)
+            ],
+            get_prev_content=False,
+        )
+
+        return {
+            group: [
+                state_event_map[v]
+                for v in itervalues(event_id_map)
+                if v in state_event_map
+            ]
+            for group, event_id_map in iteritems(group_to_ids)
+        }
+
+    def _get_state_groups_from_groups(self, groups, state_filter):
+        """Returns the state groups for a given set of groups, filtering on
+        types of state events.
+
+        Args:
+            groups(list[int]): list of state group IDs to query
+            state_filter (StateFilter): The state filter used to fetch state
+                from the database.
+        Returns:
+            Deferred[dict[int, dict[tuple[str, str], str]]]:
+                dict of state_group_id -> (dict of (type, state_key) -> event id)
+        """
+
+        return self.stores.main._get_state_groups_from_groups(groups, state_filter)
+
+    @defer.inlineCallbacks
+    def get_state_for_events(self, event_ids, state_filter=StateFilter.all()):
+        """Given a list of event_ids and type tuples, return a list of state
+        dicts for each event.
+        Args:
+            event_ids (list[string])
+            state_filter (StateFilter): The state filter used to fetch state
+                from the database.
+        Returns:
+            deferred: A dict of (event_id) -> (type, state_key) -> [state_events]
+        """
+        event_to_groups = yield self.stores.main._get_state_group_for_events(event_ids)
+
+        groups = set(itervalues(event_to_groups))
+        group_to_state = yield self.stores.main._get_state_for_groups(
+            groups, state_filter
+        )
+
+        state_event_map = yield self.stores.main.get_events(
+            [ev_id for sd in itervalues(group_to_state) for ev_id in itervalues(sd)],
+            get_prev_content=False,
+        )
+
+        event_to_state = {
+            event_id: {
+                k: state_event_map[v]
+                for k, v in iteritems(group_to_state[group])
+                if v in state_event_map
+            }
+            for event_id, group in iteritems(event_to_groups)
+        }
+
+        return {event: event_to_state[event] for event in event_ids}
+
+    @defer.inlineCallbacks
+    def get_state_ids_for_events(self, event_ids, state_filter=StateFilter.all()):
+        """
+        Get the state dicts corresponding to a list of events, containing the event_ids
+        of the state events (as opposed to the events themselves)
+
+        Args:
+            event_ids(list(str)): events whose state should be returned
+            state_filter (StateFilter): The state filter used to fetch state
+                from the database.
+
+        Returns:
+            A deferred dict from event_id -> (type, state_key) -> event_id
+        """
+        event_to_groups = yield self.stores.main._get_state_group_for_events(event_ids)
+
+        groups = set(itervalues(event_to_groups))
+        group_to_state = yield self.stores.main._get_state_for_groups(
+            groups, state_filter
+        )
+
+        event_to_state = {
+            event_id: group_to_state[group]
+            for event_id, group in iteritems(event_to_groups)
+        }
+
+        return {event: event_to_state[event] for event in event_ids}
+
+    @defer.inlineCallbacks
+    def get_state_for_event(self, event_id, state_filter=StateFilter.all()):
+        """
+        Get the state dict corresponding to a particular event
+
+        Args:
+            event_id(str): event whose state should be returned
+            state_filter (StateFilter): The state filter used to fetch state
+                from the database.
+
+        Returns:
+            A deferred dict from (type, state_key) -> state_event
+        """
+        state_map = yield self.get_state_for_events([event_id], state_filter)
+        return state_map[event_id]
+
+    @defer.inlineCallbacks
+    def get_state_ids_for_event(self, event_id, state_filter=StateFilter.all()):
+        """
+        Get the state dict corresponding to a particular event
+
+        Args:
+            event_id(str): event whose state should be returned
+            state_filter (StateFilter): The state filter used to fetch state
+                from the database.
+
+        Returns:
+            A deferred dict from (type, state_key) -> state_event
+        """
+        state_map = yield self.get_state_ids_for_events([event_id], state_filter)
+        return state_map[event_id]
+
+    def _get_state_for_groups(self, groups, state_filter=StateFilter.all()):
+        """Gets the state at each of a list of state groups, optionally
+        filtering by type/state_key
+
+        Args:
+            groups (iterable[int]): list of state groups for which we want
+                to get the state.
+            state_filter (StateFilter): The state filter used to fetch state
+                from the database.
+        Returns:
+            Deferred[dict[int, dict[tuple[str, str], str]]]:
+                dict of state_group_id -> (dict of (type, state_key) -> event id)
+        """
+        return self.stores.main._get_state_for_groups(groups, state_filter)
+
+    def store_state_group(
+        self, event_id, room_id, prev_group, delta_ids, current_state_ids
+    ):
+        """Store a new set of state, returning a newly assigned state group.
+
+        Args:
+            event_id (str): The event ID for which the state was calculated
+            room_id (str)
+            prev_group (int|None): A previous state group for the room, optional.
+            delta_ids (dict|None): The delta between state at `prev_group` and
+                `current_state_ids`, if `prev_group` was given. Same format as
+                `current_state_ids`.
+            current_state_ids (dict): The state to store. Map of (type, state_key)
+                to event_id.
+
+        Returns:
+            Deferred[int]: The state group ID
+        """
+        return self.stores.main.store_state_group(
+            event_id, room_id, prev_group, delta_ids, current_state_ids
+        )
diff --git a/synapse/storage/util/id_generators.py b/synapse/storage/util/id_generators.py
index cbb0a4810a..9d851beaa5 100644
--- a/synapse/storage/util/id_generators.py
+++ b/synapse/storage/util/id_generators.py
@@ -46,7 +46,7 @@ def _load_current_id(db_conn, table, column, step=1):
         cur.execute("SELECT MAX(%s) FROM %s" % (column, table))
     else:
         cur.execute("SELECT MIN(%s) FROM %s" % (column, table))
-    val, = cur.fetchone()
+    (val,) = cur.fetchone()
     cur.close()
     current_id = int(val) if val else step
     return (max if step > 0 else min)(current_id, step)
diff --git a/synapse/util/async_helpers.py b/synapse/util/async_helpers.py
index 804dbca443..5c4de2e69f 100644
--- a/synapse/util/async_helpers.py
+++ b/synapse/util/async_helpers.py
@@ -86,11 +86,12 @@ class ObservableDeferred(object):
 
         deferred.addCallbacks(callback, errback)
 
-    def observe(self):
+    def observe(self) -> defer.Deferred:
         """Observe the underlying deferred.
 
-        Can return either a deferred if the underlying deferred is still pending
-        (or has failed), or the actual value. Callers may need to use maybeDeferred.
+        This returns a brand new deferred that is resolved when the underlying
+        deferred is resolved. Interacting with the returned deferred does not
+        effect the underdlying deferred.
         """
         if not self._result:
             d = defer.Deferred()
@@ -105,7 +106,7 @@ class ObservableDeferred(object):
             return d
         else:
             success, res = self._result
-            return res if success else defer.fail(res)
+            return defer.succeed(res) if success else defer.fail(res)
 
     def observers(self):
         return self._observers
@@ -138,7 +139,7 @@ def concurrently_execute(func, args, limit):
     the number of concurrent executions.
 
     Args:
-        func (func): Function to execute, should return a deferred.
+        func (func): Function to execute, should return a deferred or coroutine.
         args (list): List of arguments to pass to func, each invocation of func
             gets a signle argument.
         limit (int): Maximum number of conccurent executions.
@@ -148,11 +149,10 @@ def concurrently_execute(func, args, limit):
     """
     it = iter(args)
 
-    @defer.inlineCallbacks
-    def _concurrently_execute_inner():
+    async def _concurrently_execute_inner():
         try:
             while True:
-                yield func(next(it))
+                await maybe_awaitable(func(next(it)))
         except StopIteration:
             pass
 
@@ -309,7 +309,7 @@ class Linearizer(object):
                 )
 
             else:
-                logger.warn(
+                logger.warning(
                     "Unexpected exception waiting for linearizer lock %r for key %r",
                     self.name,
                     key,
diff --git a/synapse/util/caches/__init__.py b/synapse/util/caches/__init__.py
index 43fd65d693..da5077b471 100644
--- a/synapse/util/caches/__init__.py
+++ b/synapse/util/caches/__init__.py
@@ -107,7 +107,7 @@ def register_cache(cache_type, cache_name, cache, collect_callback=None):
                 if collect_callback:
                     collect_callback()
             except Exception as e:
-                logger.warn("Error calculating metrics for %s: %s", cache_name, e)
+                logger.warning("Error calculating metrics for %s: %s", cache_name, e)
                 raise
 
             yield GaugeMetricFamily("__unused", "")
diff --git a/synapse/util/caches/descriptors.py b/synapse/util/caches/descriptors.py
index 5ac2530a6a..0e8da27f53 100644
--- a/synapse/util/caches/descriptors.py
+++ b/synapse/util/caches/descriptors.py
@@ -438,7 +438,7 @@ class CacheDescriptor(_CacheDescriptorBase):
                 if isinstance(cached_result_d, ObservableDeferred):
                     observer = cached_result_d.observe()
                 else:
-                    observer = cached_result_d
+                    observer = defer.succeed(cached_result_d)
 
             except KeyError:
                 ret = defer.maybeDeferred(
@@ -482,9 +482,8 @@ class CacheListDescriptor(_CacheDescriptorBase):
     Given a list of keys it looks in the cache to find any hits, then passes
     the list of missing keys to the wrapped function.
 
-    Once wrapped, the function returns either a Deferred which resolves to
-    the list of results, or (if all results were cached), just the list of
-    results.
+    Once wrapped, the function returns a Deferred which resolves to the list
+    of results.
     """
 
     def __init__(
@@ -618,7 +617,7 @@ class CacheListDescriptor(_CacheDescriptorBase):
                 )
                 return make_deferred_yieldable(d)
             else:
-                return results
+                return defer.succeed(results)
 
         obj.__dict__[self.orig.__name__] = wrapped
 
diff --git a/synapse/util/metrics.py b/synapse/util/metrics.py
index 4b1bcdf23c..3286804322 100644
--- a/synapse/util/metrics.py
+++ b/synapse/util/metrics.py
@@ -119,7 +119,7 @@ class Measure(object):
         context = LoggingContext.current_context()
 
         if context != self.start_context:
-            logger.warn(
+            logger.warning(
                 "Context has unexpectedly changed from '%s' to '%s'. (%r)",
                 self.start_context,
                 context,
@@ -128,7 +128,7 @@ class Measure(object):
             return
 
         if not context:
-            logger.warn("Expected context. (%r)", self.name)
+            logger.warning("Expected context. (%r)", self.name)
             return
 
         current = context.get_resource_usage()
@@ -140,7 +140,7 @@ class Measure(object):
             block_db_txn_duration.labels(self.name).inc(usage.db_txn_duration_sec)
             block_db_sched_duration.labels(self.name).inc(usage.db_sched_duration_sec)
         except ValueError:
-            logger.warn(
+            logger.warning(
                 "Failed to save metrics! OLD: %r, NEW: %r", self.start_usage, current
             )
 
diff --git a/synapse/util/rlimit.py b/synapse/util/rlimit.py
index 6c0f2bb0cf..207cd17c2a 100644
--- a/synapse/util/rlimit.py
+++ b/synapse/util/rlimit.py
@@ -33,4 +33,4 @@ def change_resource_limit(soft_file_no):
             resource.RLIMIT_CORE, (resource.RLIM_INFINITY, resource.RLIM_INFINITY)
         )
     except (ValueError, resource.error) as e:
-        logger.warn("Failed to set file or core limit: %s", e)
+        logger.warning("Failed to set file or core limit: %s", e)
diff --git a/synapse/util/versionstring.py b/synapse/util/versionstring.py
index fa404b9d75..ab7d03af3a 100644
--- a/synapse/util/versionstring.py
+++ b/synapse/util/versionstring.py
@@ -42,6 +42,7 @@ def get_version_string(module):
     try:
         null = open(os.devnull, "w")
         cwd = os.path.dirname(os.path.abspath(module.__file__))
+
         try:
             git_branch = (
                 subprocess.check_output(
@@ -51,7 +52,8 @@ def get_version_string(module):
                 .decode("ascii")
             )
             git_branch = "b=" + git_branch
-        except subprocess.CalledProcessError:
+        except (subprocess.CalledProcessError, FileNotFoundError):
+            # FileNotFoundError can arise when git is not installed
             git_branch = ""
 
         try:
@@ -63,7 +65,7 @@ def get_version_string(module):
                 .decode("ascii")
             )
             git_tag = "t=" + git_tag
-        except subprocess.CalledProcessError:
+        except (subprocess.CalledProcessError, FileNotFoundError):
             git_tag = ""
 
         try:
@@ -74,7 +76,7 @@ def get_version_string(module):
                 .strip()
                 .decode("ascii")
             )
-        except subprocess.CalledProcessError:
+        except (subprocess.CalledProcessError, FileNotFoundError):
             git_commit = ""
 
         try:
@@ -89,7 +91,7 @@ def get_version_string(module):
             )
 
             git_dirty = "dirty" if is_dirty else ""
-        except subprocess.CalledProcessError:
+        except (subprocess.CalledProcessError, FileNotFoundError):
             git_dirty = ""
 
         if git_branch or git_tag or git_commit or git_dirty:
diff --git a/synapse/visibility.py b/synapse/visibility.py
index bf0f1eebd8..8c843febd8 100644
--- a/synapse/visibility.py
+++ b/synapse/visibility.py
@@ -23,6 +23,7 @@ from twisted.internet import defer
 
 from synapse.api.constants import EventTypes, Membership
 from synapse.events.utils import prune_event
+from synapse.storage import Storage
 from synapse.storage.state import StateFilter
 from synapse.types import get_domain_from_id
 
@@ -43,14 +44,13 @@ MEMBERSHIP_PRIORITY = (
 
 @defer.inlineCallbacks
 def filter_events_for_client(
-    store, user_id, events, is_peeking=False, always_include_ids=frozenset()
+    storage: Storage, user_id, events, is_peeking=False, always_include_ids=frozenset()
 ):
     """
     Check which events a user is allowed to see
 
     Args:
-        store (synapse.storage.DataStore): our datastore (can also be a worker
-            store)
+        storage
         user_id(str): user id to be checked
         events(list[synapse.events.EventBase]): sequence of events to be checked
         is_peeking(bool): should be True if:
@@ -68,12 +68,12 @@ def filter_events_for_client(
     events = list(e for e in events if not e.internal_metadata.is_soft_failed())
 
     types = ((EventTypes.RoomHistoryVisibility, ""), (EventTypes.Member, user_id))
-    event_id_to_state = yield store.get_state_for_events(
+    event_id_to_state = yield storage.state.get_state_for_events(
         frozenset(e.event_id for e in events),
         state_filter=StateFilter.from_types(types),
     )
 
-    ignore_dict_content = yield store.get_global_account_data_by_type_for_user(
+    ignore_dict_content = yield storage.main.get_global_account_data_by_type_for_user(
         "m.ignored_user_list", user_id
     )
 
@@ -84,7 +84,7 @@ def filter_events_for_client(
         else []
     )
 
-    erased_senders = yield store.are_users_erased((e.sender for e in events))
+    erased_senders = yield storage.main.are_users_erased((e.sender for e in events))
 
     def allowed(event):
         """
@@ -213,13 +213,17 @@ def filter_events_for_client(
 
 @defer.inlineCallbacks
 def filter_events_for_server(
-    store, server_name, events, redact=True, check_history_visibility_only=False
+    storage: Storage,
+    server_name,
+    events,
+    redact=True,
+    check_history_visibility_only=False,
 ):
     """Filter a list of events based on whether given server is allowed to
     see them.
 
     Args:
-        store (DataStore)
+        storage
         server_name (str)
         events (iterable[FrozenEvent])
         redact (bool): Whether to return a redacted version of the event, or
@@ -274,7 +278,7 @@ def filter_events_for_server(
     # Lets check to see if all the events have a history visibility
     # of "shared" or "world_readable". If thats the case then we don't
     # need to check membership (as we know the server is in the room).
-    event_to_state_ids = yield store.get_state_ids_for_events(
+    event_to_state_ids = yield storage.state.get_state_ids_for_events(
         frozenset(e.event_id for e in events),
         state_filter=StateFilter.from_types(
             types=((EventTypes.RoomHistoryVisibility, ""),)
@@ -292,14 +296,14 @@ def filter_events_for_server(
     if not visibility_ids:
         all_open = True
     else:
-        event_map = yield store.get_events(visibility_ids)
+        event_map = yield storage.main.get_events(visibility_ids)
         all_open = all(
             e.content.get("history_visibility") in (None, "shared", "world_readable")
             for e in itervalues(event_map)
         )
 
     if not check_history_visibility_only:
-        erased_senders = yield store.are_users_erased((e.sender for e in events))
+        erased_senders = yield storage.main.are_users_erased((e.sender for e in events))
     else:
         # We don't want to check whether users are erased, which is equivalent
         # to no users having been erased.
@@ -328,7 +332,7 @@ def filter_events_for_server(
 
     # first, for each event we're wanting to return, get the event_ids
     # of the history vis and membership state at those events.
-    event_to_state_ids = yield store.get_state_ids_for_events(
+    event_to_state_ids = yield storage.state.get_state_ids_for_events(
         frozenset(e.event_id for e in events),
         state_filter=StateFilter.from_types(
             types=((EventTypes.RoomHistoryVisibility, ""), (EventTypes.Member, None))
@@ -358,7 +362,7 @@ def filter_events_for_server(
             return False
         return state_key[idx + 1 :] == server_name
 
-    event_map = yield store.get_events(
+    event_map = yield storage.main.get_events(
         [
             e_id
             for e_id, key in iteritems(event_id_to_state_key)
diff --git a/tests/api/test_filtering.py b/tests/api/test_filtering.py
index 6ba623de13..2dc5052249 100644
--- a/tests/api/test_filtering.py
+++ b/tests/api/test_filtering.py
@@ -19,6 +19,7 @@ import jsonschema
 
 from twisted.internet import defer
 
+from synapse.api.constants import EventContentFields
 from synapse.api.errors import SynapseError
 from synapse.api.filtering import Filter
 from synapse.events import FrozenEvent
@@ -95,6 +96,8 @@ class FilteringTestCase(unittest.TestCase):
                         "types": ["m.room.message"],
                         "not_rooms": ["!726s6s6q:example.com"],
                         "not_senders": ["@spam:example.com"],
+                        "org.matrix.labels": ["#fun"],
+                        "org.matrix.not_labels": ["#work"],
                     },
                     "ephemeral": {
                         "types": ["m.receipt", "m.typing"],
@@ -320,6 +323,46 @@ class FilteringTestCase(unittest.TestCase):
         )
         self.assertFalse(Filter(definition).check(event))
 
+    def test_filter_labels(self):
+        definition = {"org.matrix.labels": ["#fun"]}
+        event = MockEvent(
+            sender="@foo:bar",
+            type="m.room.message",
+            room_id="!secretbase:unknown",
+            content={EventContentFields.LABELS: ["#fun"]},
+        )
+
+        self.assertTrue(Filter(definition).check(event))
+
+        event = MockEvent(
+            sender="@foo:bar",
+            type="m.room.message",
+            room_id="!secretbase:unknown",
+            content={EventContentFields.LABELS: ["#notfun"]},
+        )
+
+        self.assertFalse(Filter(definition).check(event))
+
+    def test_filter_not_labels(self):
+        definition = {"org.matrix.not_labels": ["#fun"]}
+        event = MockEvent(
+            sender="@foo:bar",
+            type="m.room.message",
+            room_id="!secretbase:unknown",
+            content={EventContentFields.LABELS: ["#fun"]},
+        )
+
+        self.assertFalse(Filter(definition).check(event))
+
+        event = MockEvent(
+            sender="@foo:bar",
+            type="m.room.message",
+            room_id="!secretbase:unknown",
+            content={EventContentFields.LABELS: ["#notfun"]},
+        )
+
+        self.assertTrue(Filter(definition).check(event))
+
     @defer.inlineCallbacks
     def test_filter_presence_match(self):
         user_filter_json = {"presence": {"types": ["m.*"]}}
diff --git a/tests/crypto/test_keyring.py b/tests/crypto/test_keyring.py
index c4f0bbd3dd..8efd39c7f7 100644
--- a/tests/crypto/test_keyring.py
+++ b/tests/crypto/test_keyring.py
@@ -178,7 +178,7 @@ class KeyringTestCase(unittest.HomeserverTestCase):
         kr = keyring.Keyring(self.hs)
 
         key1 = signedjson.key.generate_signing_key(1)
-        r = self.hs.datastore.store_server_verify_keys(
+        r = self.hs.get_datastore().store_server_verify_keys(
             "server9",
             time.time() * 1000,
             [("server9", get_key_id(key1), FetchKeyResult(get_verify_key(key1), 1000))],
@@ -209,7 +209,7 @@ class KeyringTestCase(unittest.HomeserverTestCase):
         )
 
         key1 = signedjson.key.generate_signing_key(1)
-        r = self.hs.datastore.store_server_verify_keys(
+        r = self.hs.get_datastore().store_server_verify_keys(
             "server9",
             time.time() * 1000,
             [("server9", get_key_id(key1), FetchKeyResult(get_verify_key(key1), None))],
diff --git a/tests/handlers/test_federation.py b/tests/handlers/test_federation.py
index d56220f403..b4d92cf732 100644
--- a/tests/handlers/test_federation.py
+++ b/tests/handlers/test_federation.py
@@ -12,13 +12,19 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+import logging
+
 from synapse.api.constants import EventTypes
 from synapse.api.errors import AuthError, Codes
+from synapse.federation.federation_base import event_from_pdu_json
+from synapse.logging.context import LoggingContext, run_in_background
 from synapse.rest import admin
 from synapse.rest.client.v1 import login, room
 
 from tests import unittest
 
+logger = logging.getLogger(__name__)
+
 
 class FederationTestCase(unittest.HomeserverTestCase):
     servlets = [
@@ -79,3 +85,123 @@ class FederationTestCase(unittest.HomeserverTestCase):
         self.assertEqual(failure.code, 403, failure)
         self.assertEqual(failure.errcode, Codes.FORBIDDEN, failure)
         self.assertEqual(failure.msg, "You are not invited to this room.")
+
+    def test_rejected_message_event_state(self):
+        """
+        Check that we store the state group correctly for rejected non-state events.
+
+        Regression test for #6289.
+        """
+        OTHER_SERVER = "otherserver"
+        OTHER_USER = "@otheruser:" + OTHER_SERVER
+
+        # create the room
+        user_id = self.register_user("kermit", "test")
+        tok = self.login("kermit", "test")
+        room_id = self.helper.create_room_as(room_creator=user_id, tok=tok)
+
+        # pretend that another server has joined
+        join_event = self._build_and_send_join_event(OTHER_SERVER, OTHER_USER, room_id)
+
+        # check the state group
+        sg = self.successResultOf(
+            self.store._get_state_group_for_event(join_event.event_id)
+        )
+
+        # build and send an event which will be rejected
+        ev = event_from_pdu_json(
+            {
+                "type": EventTypes.Message,
+                "content": {},
+                "room_id": room_id,
+                "sender": "@yetanotheruser:" + OTHER_SERVER,
+                "depth": join_event["depth"] + 1,
+                "prev_events": [join_event.event_id],
+                "auth_events": [],
+                "origin_server_ts": self.clock.time_msec(),
+            },
+            join_event.format_version,
+        )
+
+        with LoggingContext(request="send_rejected"):
+            d = run_in_background(self.handler.on_receive_pdu, OTHER_SERVER, ev)
+        self.get_success(d)
+
+        # that should have been rejected
+        e = self.get_success(self.store.get_event(ev.event_id, allow_rejected=True))
+        self.assertIsNotNone(e.rejected_reason)
+
+        # ... and the state group should be the same as before
+        sg2 = self.successResultOf(self.store._get_state_group_for_event(ev.event_id))
+
+        self.assertEqual(sg, sg2)
+
+    def test_rejected_state_event_state(self):
+        """
+        Check that we store the state group correctly for rejected state events.
+
+        Regression test for #6289.
+        """
+        OTHER_SERVER = "otherserver"
+        OTHER_USER = "@otheruser:" + OTHER_SERVER
+
+        # create the room
+        user_id = self.register_user("kermit", "test")
+        tok = self.login("kermit", "test")
+        room_id = self.helper.create_room_as(room_creator=user_id, tok=tok)
+
+        # pretend that another server has joined
+        join_event = self._build_and_send_join_event(OTHER_SERVER, OTHER_USER, room_id)
+
+        # check the state group
+        sg = self.successResultOf(
+            self.store._get_state_group_for_event(join_event.event_id)
+        )
+
+        # build and send an event which will be rejected
+        ev = event_from_pdu_json(
+            {
+                "type": "org.matrix.test",
+                "state_key": "test_key",
+                "content": {},
+                "room_id": room_id,
+                "sender": "@yetanotheruser:" + OTHER_SERVER,
+                "depth": join_event["depth"] + 1,
+                "prev_events": [join_event.event_id],
+                "auth_events": [],
+                "origin_server_ts": self.clock.time_msec(),
+            },
+            join_event.format_version,
+        )
+
+        with LoggingContext(request="send_rejected"):
+            d = run_in_background(self.handler.on_receive_pdu, OTHER_SERVER, ev)
+        self.get_success(d)
+
+        # that should have been rejected
+        e = self.get_success(self.store.get_event(ev.event_id, allow_rejected=True))
+        self.assertIsNotNone(e.rejected_reason)
+
+        # ... and the state group should be the same as before
+        sg2 = self.successResultOf(self.store._get_state_group_for_event(ev.event_id))
+
+        self.assertEqual(sg, sg2)
+
+    def _build_and_send_join_event(self, other_server, other_user, room_id):
+        join_event = self.get_success(
+            self.handler.on_make_join_request(other_server, room_id, other_user)
+        )
+        # the auth code requires that a signature exists, but doesn't check that
+        # signature... go figure.
+        join_event.signatures[other_server] = {"x": "y"}
+        with LoggingContext(request="send_join"):
+            d = run_in_background(
+                self.handler.on_send_join_request, other_server, join_event
+            )
+        self.get_success(d)
+
+        # sanity-check: the room should show that the new user is a member
+        r = self.get_success(self.store.get_current_state_ids(room_id))
+        self.assertEqual(r[(EventTypes.Member, other_user)], join_event.event_id)
+
+        return join_event
diff --git a/tests/handlers/test_typing.py b/tests/handlers/test_typing.py
index 67f1013051..5ec568f4e6 100644
--- a/tests/handlers/test_typing.py
+++ b/tests/handlers/test_typing.py
@@ -73,7 +73,7 @@ class TypingNotificationsTestCase(unittest.HomeserverTestCase):
                         "get_received_txn_response",
                         "set_received_txn_response",
                         "get_destination_retry_timings",
-                        "get_devices_by_remote",
+                        "get_device_updates_by_remote",
                         # Bits that user_directory needs
                         "get_user_directory_stream_pos",
                         "get_current_state_deltas",
@@ -109,7 +109,7 @@ class TypingNotificationsTestCase(unittest.HomeserverTestCase):
             retry_timings_res
         )
 
-        self.datastore.get_devices_by_remote.return_value = (0, [])
+        self.datastore.get_device_updates_by_remote.return_value = (0, [])
 
         def get_received_txn_response(*args):
             return defer.succeed(None)
@@ -144,6 +144,9 @@ class TypingNotificationsTestCase(unittest.HomeserverTestCase):
         self.datastore.get_to_device_stream_token = lambda: 0
         self.datastore.get_new_device_msgs_for_remote = lambda *args, **kargs: ([], 0)
         self.datastore.delete_device_msgs_for_remote = lambda *args, **kargs: None
+        self.datastore.set_received_txn_response = lambda *args, **kwargs: defer.succeed(
+            None
+        )
 
     def test_started_typing_local(self):
         self.room_members = [U_APPLE, U_BANANA]
diff --git a/tests/http/__init__.py b/tests/http/__init__.py
index 2d5dba6464..2096ba3c91 100644
--- a/tests/http/__init__.py
+++ b/tests/http/__init__.py
@@ -20,6 +20,23 @@ from zope.interface import implementer
 from OpenSSL import SSL
 from OpenSSL.SSL import Connection
 from twisted.internet.interfaces import IOpenSSLServerConnectionCreator
+from twisted.internet.ssl import Certificate, trustRootFromCertificates
+from twisted.web.client import BrowserLikePolicyForHTTPS  # noqa: F401
+from twisted.web.iweb import IPolicyForHTTPS  # noqa: F401
+
+
+def get_test_https_policy():
+    """Get a test IPolicyForHTTPS which trusts the test CA cert
+
+    Returns:
+        IPolicyForHTTPS
+    """
+    ca_file = get_test_ca_cert_file()
+    with open(ca_file) as stream:
+        content = stream.read()
+    cert = Certificate.loadPEM(content)
+    trust_root = trustRootFromCertificates([cert])
+    return BrowserLikePolicyForHTTPS(trustRoot=trust_root)
 
 
 def get_test_ca_cert_file():
diff --git a/tests/http/federation/test_matrix_federation_agent.py b/tests/http/federation/test_matrix_federation_agent.py
index 71d7025264..cfcd98ff7d 100644
--- a/tests/http/federation/test_matrix_federation_agent.py
+++ b/tests/http/federation/test_matrix_federation_agent.py
@@ -124,19 +124,24 @@ class MatrixFederationAgentTests(unittest.TestCase):
             FakeTransport(client_protocol, self.reactor, server_tls_protocol)
         )
 
+        # grab a hold of the TLS connection, in case it gets torn down
+        server_tls_connection = server_tls_protocol._tlsConnection
+
+        # fish the test server back out of the server-side TLS protocol.
+        http_protocol = server_tls_protocol.wrappedProtocol
+
         # give the reactor a pump to get the TLS juices flowing.
         self.reactor.pump((0.1,))
 
         # check the SNI
-        server_name = server_tls_protocol._tlsConnection.get_servername()
+        server_name = server_tls_connection.get_servername()
         self.assertEqual(
             server_name,
             expected_sni,
             "Expected SNI %s but got %s" % (expected_sni, server_name),
         )
 
-        # fish the test server back out of the server-side TLS protocol.
-        return server_tls_protocol.wrappedProtocol
+        return http_protocol
 
     @defer.inlineCallbacks
     def _make_get_request(self, uri):
diff --git a/tests/http/test_proxyagent.py b/tests/http/test_proxyagent.py
new file mode 100644
index 0000000000..22abf76515
--- /dev/null
+++ b/tests/http/test_proxyagent.py
@@ -0,0 +1,334 @@
+# -*- coding: utf-8 -*-
+# Copyright 2019 The Matrix.org Foundation C.I.C.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+import logging
+
+import treq
+
+from twisted.internet import interfaces  # noqa: F401
+from twisted.internet.protocol import Factory
+from twisted.protocols.tls import TLSMemoryBIOFactory
+from twisted.web.http import HTTPChannel
+
+from synapse.http.proxyagent import ProxyAgent
+
+from tests.http import TestServerTLSConnectionFactory, get_test_https_policy
+from tests.server import FakeTransport, ThreadedMemoryReactorClock
+from tests.unittest import TestCase
+
+logger = logging.getLogger(__name__)
+
+HTTPFactory = Factory.forProtocol(HTTPChannel)
+
+
+class MatrixFederationAgentTests(TestCase):
+    def setUp(self):
+        self.reactor = ThreadedMemoryReactorClock()
+
+    def _make_connection(
+        self, client_factory, server_factory, ssl=False, expected_sni=None
+    ):
+        """Builds a test server, and completes the outgoing client connection
+
+        Args:
+            client_factory (interfaces.IProtocolFactory): the the factory that the
+                application is trying to use to make the outbound connection. We will
+                invoke it to build the client Protocol
+
+            server_factory (interfaces.IProtocolFactory): a factory to build the
+                server-side protocol
+
+            ssl (bool): If true, we will expect an ssl connection and wrap
+                server_factory with a TLSMemoryBIOFactory
+
+            expected_sni (bytes|None): the expected SNI value
+
+        Returns:
+            IProtocol: the server Protocol returned by server_factory
+        """
+        if ssl:
+            server_factory = _wrap_server_factory_for_tls(server_factory)
+
+        server_protocol = server_factory.buildProtocol(None)
+
+        # now, tell the client protocol factory to build the client protocol,
+        # and wire the output of said protocol up to the server via
+        # a FakeTransport.
+        #
+        # Normally this would be done by the TCP socket code in Twisted, but we are
+        # stubbing that out here.
+        client_protocol = client_factory.buildProtocol(None)
+        client_protocol.makeConnection(
+            FakeTransport(server_protocol, self.reactor, client_protocol)
+        )
+
+        # tell the server protocol to send its stuff back to the client, too
+        server_protocol.makeConnection(
+            FakeTransport(client_protocol, self.reactor, server_protocol)
+        )
+
+        if ssl:
+            http_protocol = server_protocol.wrappedProtocol
+            tls_connection = server_protocol._tlsConnection
+        else:
+            http_protocol = server_protocol
+            tls_connection = None
+
+        # give the reactor a pump to get the TLS juices flowing (if needed)
+        self.reactor.advance(0)
+
+        if expected_sni is not None:
+            server_name = tls_connection.get_servername()
+            self.assertEqual(
+                server_name,
+                expected_sni,
+                "Expected SNI %s but got %s" % (expected_sni, server_name),
+            )
+
+        return http_protocol
+
+    def test_http_request(self):
+        agent = ProxyAgent(self.reactor)
+
+        self.reactor.lookups["test.com"] = "1.2.3.4"
+        d = agent.request(b"GET", b"http://test.com")
+
+        # there should be a pending TCP connection
+        clients = self.reactor.tcpClients
+        self.assertEqual(len(clients), 1)
+        (host, port, client_factory, _timeout, _bindAddress) = clients[0]
+        self.assertEqual(host, "1.2.3.4")
+        self.assertEqual(port, 80)
+
+        # make a test server, and wire up the client
+        http_server = self._make_connection(
+            client_factory, _get_test_protocol_factory()
+        )
+
+        # the FakeTransport is async, so we need to pump the reactor
+        self.reactor.advance(0)
+
+        # now there should be a pending request
+        self.assertEqual(len(http_server.requests), 1)
+
+        request = http_server.requests[0]
+        self.assertEqual(request.method, b"GET")
+        self.assertEqual(request.path, b"/")
+        self.assertEqual(request.requestHeaders.getRawHeaders(b"host"), [b"test.com"])
+        request.write(b"result")
+        request.finish()
+
+        self.reactor.advance(0)
+
+        resp = self.successResultOf(d)
+        body = self.successResultOf(treq.content(resp))
+        self.assertEqual(body, b"result")
+
+    def test_https_request(self):
+        agent = ProxyAgent(self.reactor, contextFactory=get_test_https_policy())
+
+        self.reactor.lookups["test.com"] = "1.2.3.4"
+        d = agent.request(b"GET", b"https://test.com/abc")
+
+        # there should be a pending TCP connection
+        clients = self.reactor.tcpClients
+        self.assertEqual(len(clients), 1)
+        (host, port, client_factory, _timeout, _bindAddress) = clients[0]
+        self.assertEqual(host, "1.2.3.4")
+        self.assertEqual(port, 443)
+
+        # make a test server, and wire up the client
+        http_server = self._make_connection(
+            client_factory,
+            _get_test_protocol_factory(),
+            ssl=True,
+            expected_sni=b"test.com",
+        )
+
+        # the FakeTransport is async, so we need to pump the reactor
+        self.reactor.advance(0)
+
+        # now there should be a pending request
+        self.assertEqual(len(http_server.requests), 1)
+
+        request = http_server.requests[0]
+        self.assertEqual(request.method, b"GET")
+        self.assertEqual(request.path, b"/abc")
+        self.assertEqual(request.requestHeaders.getRawHeaders(b"host"), [b"test.com"])
+        request.write(b"result")
+        request.finish()
+
+        self.reactor.advance(0)
+
+        resp = self.successResultOf(d)
+        body = self.successResultOf(treq.content(resp))
+        self.assertEqual(body, b"result")
+
+    def test_http_request_via_proxy(self):
+        agent = ProxyAgent(self.reactor, http_proxy=b"proxy.com:8888")
+
+        self.reactor.lookups["proxy.com"] = "1.2.3.5"
+        d = agent.request(b"GET", b"http://test.com")
+
+        # there should be a pending TCP connection
+        clients = self.reactor.tcpClients
+        self.assertEqual(len(clients), 1)
+        (host, port, client_factory, _timeout, _bindAddress) = clients[0]
+        self.assertEqual(host, "1.2.3.5")
+        self.assertEqual(port, 8888)
+
+        # make a test server, and wire up the client
+        http_server = self._make_connection(
+            client_factory, _get_test_protocol_factory()
+        )
+
+        # the FakeTransport is async, so we need to pump the reactor
+        self.reactor.advance(0)
+
+        # now there should be a pending request
+        self.assertEqual(len(http_server.requests), 1)
+
+        request = http_server.requests[0]
+        self.assertEqual(request.method, b"GET")
+        self.assertEqual(request.path, b"http://test.com")
+        self.assertEqual(request.requestHeaders.getRawHeaders(b"host"), [b"test.com"])
+        request.write(b"result")
+        request.finish()
+
+        self.reactor.advance(0)
+
+        resp = self.successResultOf(d)
+        body = self.successResultOf(treq.content(resp))
+        self.assertEqual(body, b"result")
+
+    def test_https_request_via_proxy(self):
+        agent = ProxyAgent(
+            self.reactor,
+            contextFactory=get_test_https_policy(),
+            https_proxy=b"proxy.com",
+        )
+
+        self.reactor.lookups["proxy.com"] = "1.2.3.5"
+        d = agent.request(b"GET", b"https://test.com/abc")
+
+        # there should be a pending TCP connection
+        clients = self.reactor.tcpClients
+        self.assertEqual(len(clients), 1)
+        (host, port, client_factory, _timeout, _bindAddress) = clients[0]
+        self.assertEqual(host, "1.2.3.5")
+        self.assertEqual(port, 1080)
+
+        # make a test HTTP server, and wire up the client
+        proxy_server = self._make_connection(
+            client_factory, _get_test_protocol_factory()
+        )
+
+        # fish the transports back out so that we can do the old switcheroo
+        s2c_transport = proxy_server.transport
+        client_protocol = s2c_transport.other
+        c2s_transport = client_protocol.transport
+
+        # the FakeTransport is async, so we need to pump the reactor
+        self.reactor.advance(0)
+
+        # now there should be a pending CONNECT request
+        self.assertEqual(len(proxy_server.requests), 1)
+
+        request = proxy_server.requests[0]
+        self.assertEqual(request.method, b"CONNECT")
+        self.assertEqual(request.path, b"test.com:443")
+
+        # tell the proxy server not to close the connection
+        proxy_server.persistent = True
+
+        # this just stops the http Request trying to do a chunked response
+        # request.setHeader(b"Content-Length", b"0")
+        request.finish()
+
+        # now we can replace the proxy channel with a new, SSL-wrapped HTTP channel
+        ssl_factory = _wrap_server_factory_for_tls(_get_test_protocol_factory())
+        ssl_protocol = ssl_factory.buildProtocol(None)
+        http_server = ssl_protocol.wrappedProtocol
+
+        ssl_protocol.makeConnection(
+            FakeTransport(client_protocol, self.reactor, ssl_protocol)
+        )
+        c2s_transport.other = ssl_protocol
+
+        self.reactor.advance(0)
+
+        server_name = ssl_protocol._tlsConnection.get_servername()
+        expected_sni = b"test.com"
+        self.assertEqual(
+            server_name,
+            expected_sni,
+            "Expected SNI %s but got %s" % (expected_sni, server_name),
+        )
+
+        # now there should be a pending request
+        self.assertEqual(len(http_server.requests), 1)
+
+        request = http_server.requests[0]
+        self.assertEqual(request.method, b"GET")
+        self.assertEqual(request.path, b"/abc")
+        self.assertEqual(request.requestHeaders.getRawHeaders(b"host"), [b"test.com"])
+        request.write(b"result")
+        request.finish()
+
+        self.reactor.advance(0)
+
+        resp = self.successResultOf(d)
+        body = self.successResultOf(treq.content(resp))
+        self.assertEqual(body, b"result")
+
+
+def _wrap_server_factory_for_tls(factory, sanlist=None):
+    """Wrap an existing Protocol Factory with a test TLSMemoryBIOFactory
+
+    The resultant factory will create a TLS server which presents a certificate
+    signed by our test CA, valid for the domains in `sanlist`
+
+    Args:
+        factory (interfaces.IProtocolFactory): protocol factory to wrap
+        sanlist (iterable[bytes]): list of domains the cert should be valid for
+
+    Returns:
+        interfaces.IProtocolFactory
+    """
+    if sanlist is None:
+        sanlist = [b"DNS:test.com"]
+
+    connection_creator = TestServerTLSConnectionFactory(sanlist=sanlist)
+    return TLSMemoryBIOFactory(
+        connection_creator, isClient=False, wrappedFactory=factory
+    )
+
+
+def _get_test_protocol_factory():
+    """Get a protocol Factory which will build an HTTPChannel
+
+    Returns:
+        interfaces.IProtocolFactory
+    """
+    server_factory = Factory.forProtocol(HTTPChannel)
+
+    # Request.finish expects the factory to have a 'log' method.
+    server_factory.log = _log_request
+
+    return server_factory
+
+
+def _log_request(request):
+    """Implements Factory.log, which is expected by Request.finish"""
+    logger.info("Completed request %s", request)
diff --git a/tests/push/test_http.py b/tests/push/test_http.py
index 8ce6bb62da..af2327fb66 100644
--- a/tests/push/test_http.py
+++ b/tests/push/test_http.py
@@ -50,7 +50,7 @@ class HTTPPusherTests(HomeserverTestCase):
         config = self.default_config()
         config["start_pushers"] = True
 
-        hs = self.setup_test_homeserver(config=config, simple_http_client=m)
+        hs = self.setup_test_homeserver(config=config, proxied_http_client=m)
 
         return hs
 
diff --git a/tests/replication/slave/storage/_base.py b/tests/replication/slave/storage/_base.py
index 104349cdbd..4f924ce451 100644
--- a/tests/replication/slave/storage/_base.py
+++ b/tests/replication/slave/storage/_base.py
@@ -41,6 +41,7 @@ class BaseSlavedStoreTestCase(unittest.HomeserverTestCase):
     def prepare(self, reactor, clock, hs):
 
         self.master_store = self.hs.get_datastore()
+        self.storage = hs.get_storage()
         self.slaved_store = self.STORE_TYPE(self.hs.get_db_conn(), self.hs)
         self.event_id = 0
 
diff --git a/tests/replication/slave/storage/test_events.py b/tests/replication/slave/storage/test_events.py
index a368117b43..b68e9fe082 100644
--- a/tests/replication/slave/storage/test_events.py
+++ b/tests/replication/slave/storage/test_events.py
@@ -234,7 +234,9 @@ class SlavedEventStoreTestCase(BaseSlavedStoreTestCase):
             type="m.room.member", sender=USER_ID_2, key=USER_ID_2, membership="join"
         )
         msg, msgctx = self.build_event()
-        self.get_success(self.master_store.persist_events([(j2, j2ctx), (msg, msgctx)]))
+        self.get_success(
+            self.storage.persistence.persist_events([(j2, j2ctx), (msg, msgctx)])
+        )
         self.replicate()
 
         event_source = RoomEventSource(self.hs)
@@ -290,10 +292,12 @@ class SlavedEventStoreTestCase(BaseSlavedStoreTestCase):
 
         if backfill:
             self.get_success(
-                self.master_store.persist_events([(event, context)], backfilled=True)
+                self.storage.persistence.persist_events(
+                    [(event, context)], backfilled=True
+                )
             )
         else:
-            self.get_success(self.master_store.persist_event(event, context))
+            self.get_success(self.storage.persistence.persist_event(event, context))
 
         return event
 
diff --git a/tests/rest/admin/test_admin.py b/tests/rest/admin/test_admin.py
index d3a4f717f7..8e1ca8b738 100644
--- a/tests/rest/admin/test_admin.py
+++ b/tests/rest/admin/test_admin.py
@@ -561,3 +561,81 @@ class DeleteGroupTestCase(unittest.HomeserverTestCase):
         self.assertEqual(200, int(channel.result["code"]), msg=channel.result["body"])
 
         return channel.json_body["groups"]
+
+
+class PurgeRoomTestCase(unittest.HomeserverTestCase):
+    """Test /purge_room admin API.
+    """
+
+    servlets = [
+        synapse.rest.admin.register_servlets,
+        login.register_servlets,
+        room.register_servlets,
+    ]
+
+    def prepare(self, reactor, clock, hs):
+        self.store = hs.get_datastore()
+
+        self.admin_user = self.register_user("admin", "pass", admin=True)
+        self.admin_user_tok = self.login("admin", "pass")
+
+    def test_purge_room(self):
+        room_id = self.helper.create_room_as(self.admin_user, tok=self.admin_user_tok)
+
+        # All users have to have left the room.
+        self.helper.leave(room_id, user=self.admin_user, tok=self.admin_user_tok)
+
+        url = "/_synapse/admin/v1/purge_room"
+        request, channel = self.make_request(
+            "POST",
+            url.encode("ascii"),
+            {"room_id": room_id},
+            access_token=self.admin_user_tok,
+        )
+        self.render(request)
+
+        self.assertEqual(200, int(channel.result["code"]), msg=channel.result["body"])
+
+        # Test that the following tables have been purged of all rows related to the room.
+        for table in (
+            "current_state_events",
+            "event_backward_extremities",
+            "event_forward_extremities",
+            "event_json",
+            "event_push_actions",
+            "event_search",
+            "events",
+            "group_rooms",
+            "public_room_list_stream",
+            "receipts_graph",
+            "receipts_linearized",
+            "room_aliases",
+            "room_depth",
+            "room_memberships",
+            "room_stats_state",
+            "room_stats_current",
+            "room_stats_historical",
+            "room_stats_earliest_token",
+            "rooms",
+            "stream_ordering_to_exterm",
+            "users_in_public_rooms",
+            "users_who_share_private_rooms",
+            "appservice_room_list",
+            "e2e_room_keys",
+            "event_push_summary",
+            "pusher_throttle",
+            "group_summary_rooms",
+            "local_invites",
+            "room_account_data",
+            "room_tags",
+        ):
+            count = self.get_success(
+                self.store._simple_select_one_onecol(
+                    table="events",
+                    keyvalues={"room_id": room_id},
+                    retcol="COUNT(*)",
+                    desc="test_purge_room",
+                )
+            )
+
+            self.assertEqual(count, 0, msg="Rows not purged in {}".format(table))
diff --git a/tests/rest/client/v1/test_rooms.py b/tests/rest/client/v1/test_rooms.py
index 2f2ca74611..5e38fd6ced 100644
--- a/tests/rest/client/v1/test_rooms.py
+++ b/tests/rest/client/v1/test_rooms.py
@@ -24,7 +24,7 @@ from six.moves.urllib import parse as urlparse
 from twisted.internet import defer
 
 import synapse.rest.admin
-from synapse.api.constants import Membership
+from synapse.api.constants import EventContentFields, EventTypes, Membership
 from synapse.rest.client.v1 import login, profile, room
 
 from tests import unittest
@@ -811,6 +811,105 @@ class RoomMessageListTestCase(RoomBase):
         self.assertTrue("chunk" in channel.json_body)
         self.assertTrue("end" in channel.json_body)
 
+    def test_filter_labels(self):
+        """Test that we can filter by a label."""
+        message_filter = json.dumps(
+            {"types": [EventTypes.Message], "org.matrix.labels": ["#fun"]}
+        )
+
+        events = self._test_filter_labels(message_filter)
+
+        self.assertEqual(len(events), 2, [event["content"] for event in events])
+        self.assertEqual(events[0]["content"]["body"], "with right label", events[0])
+        self.assertEqual(events[1]["content"]["body"], "with right label", events[1])
+
+    def test_filter_not_labels(self):
+        """Test that we can filter by the absence of a label."""
+        message_filter = json.dumps(
+            {"types": [EventTypes.Message], "org.matrix.not_labels": ["#fun"]}
+        )
+
+        events = self._test_filter_labels(message_filter)
+
+        self.assertEqual(len(events), 3, [event["content"] for event in events])
+        self.assertEqual(events[0]["content"]["body"], "without label", events[0])
+        self.assertEqual(events[1]["content"]["body"], "with wrong label", events[1])
+        self.assertEqual(
+            events[2]["content"]["body"], "with two wrong labels", events[2]
+        )
+
+    def test_filter_labels_not_labels(self):
+        """Test that we can filter by both a label and the absence of another label."""
+        sync_filter = json.dumps(
+            {
+                "types": [EventTypes.Message],
+                "org.matrix.labels": ["#work"],
+                "org.matrix.not_labels": ["#notfun"],
+            }
+        )
+
+        events = self._test_filter_labels(sync_filter)
+
+        self.assertEqual(len(events), 1, [event["content"] for event in events])
+        self.assertEqual(events[0]["content"]["body"], "with wrong label", events[0])
+
+    def _test_filter_labels(self, message_filter):
+        self.helper.send_event(
+            room_id=self.room_id,
+            type=EventTypes.Message,
+            content={
+                "msgtype": "m.text",
+                "body": "with right label",
+                EventContentFields.LABELS: ["#fun"],
+            },
+        )
+
+        self.helper.send_event(
+            room_id=self.room_id,
+            type=EventTypes.Message,
+            content={"msgtype": "m.text", "body": "without label"},
+        )
+
+        self.helper.send_event(
+            room_id=self.room_id,
+            type=EventTypes.Message,
+            content={
+                "msgtype": "m.text",
+                "body": "with wrong label",
+                EventContentFields.LABELS: ["#work"],
+            },
+        )
+
+        self.helper.send_event(
+            room_id=self.room_id,
+            type=EventTypes.Message,
+            content={
+                "msgtype": "m.text",
+                "body": "with two wrong labels",
+                EventContentFields.LABELS: ["#work", "#notfun"],
+            },
+        )
+
+        self.helper.send_event(
+            room_id=self.room_id,
+            type=EventTypes.Message,
+            content={
+                "msgtype": "m.text",
+                "body": "with right label",
+                EventContentFields.LABELS: ["#fun"],
+            },
+        )
+
+        token = "s0_0_0_0_0_0_0_0_0"
+        request, channel = self.make_request(
+            "GET",
+            "/rooms/%s/messages?access_token=x&from=%s&filter=%s"
+            % (self.room_id, token, message_filter),
+        )
+        self.render(request)
+
+        return channel.json_body["chunk"]
+
 
 class RoomSearchTestCase(unittest.HomeserverTestCase):
     servlets = [
diff --git a/tests/rest/client/v1/utils.py b/tests/rest/client/v1/utils.py
index cdded88b7f..8ea0cb05ea 100644
--- a/tests/rest/client/v1/utils.py
+++ b/tests/rest/client/v1/utils.py
@@ -106,13 +106,22 @@ class RestHelper(object):
         self.auth_user_id = temp_id
 
     def send(self, room_id, body=None, txn_id=None, tok=None, expect_code=200):
-        if txn_id is None:
-            txn_id = "m%s" % (str(time.time()))
         if body is None:
             body = "body_text_here"
 
-        path = "/_matrix/client/r0/rooms/%s/send/m.room.message/%s" % (room_id, txn_id)
         content = {"msgtype": "m.text", "body": body}
+
+        return self.send_event(
+            room_id, "m.room.message", content, txn_id, tok, expect_code
+        )
+
+    def send_event(
+        self, room_id, type, content={}, txn_id=None, tok=None, expect_code=200
+    ):
+        if txn_id is None:
+            txn_id = "m%s" % (str(time.time()))
+
+        path = "/_matrix/client/r0/rooms/%s/send/%s/%s" % (room_id, type, txn_id)
         if tok:
             path = path + "?access_token=%s" % tok
 
diff --git a/tests/rest/client/v2_alpha/test_sync.py b/tests/rest/client/v2_alpha/test_sync.py
index 71895094bd..3283c0e47b 100644
--- a/tests/rest/client/v2_alpha/test_sync.py
+++ b/tests/rest/client/v2_alpha/test_sync.py
@@ -12,10 +12,12 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+import json
 
 from mock import Mock
 
 import synapse.rest.admin
+from synapse.api.constants import EventContentFields, EventTypes
 from synapse.rest.client.v1 import login, room
 from synapse.rest.client.v2_alpha import sync
 
@@ -26,7 +28,12 @@ from tests.server import TimedOutException
 class FilterTestCase(unittest.HomeserverTestCase):
 
     user_id = "@apple:test"
-    servlets = [sync.register_servlets]
+    servlets = [
+        synapse.rest.admin.register_servlets_for_client_rest_resource,
+        room.register_servlets,
+        login.register_servlets,
+        sync.register_servlets,
+    ]
 
     def make_homeserver(self, reactor, clock):
 
@@ -70,6 +77,140 @@ class FilterTestCase(unittest.HomeserverTestCase):
         )
 
 
+class SyncFilterTestCase(unittest.HomeserverTestCase):
+    servlets = [
+        synapse.rest.admin.register_servlets_for_client_rest_resource,
+        room.register_servlets,
+        login.register_servlets,
+        sync.register_servlets,
+    ]
+
+    def test_sync_filter_labels(self):
+        """Test that we can filter by a label."""
+        sync_filter = json.dumps(
+            {
+                "room": {
+                    "timeline": {
+                        "types": [EventTypes.Message],
+                        "org.matrix.labels": ["#fun"],
+                    }
+                }
+            }
+        )
+
+        events = self._test_sync_filter_labels(sync_filter)
+
+        self.assertEqual(len(events), 2, [event["content"] for event in events])
+        self.assertEqual(events[0]["content"]["body"], "with right label", events[0])
+        self.assertEqual(events[1]["content"]["body"], "with right label", events[1])
+
+    def test_sync_filter_not_labels(self):
+        """Test that we can filter by the absence of a label."""
+        sync_filter = json.dumps(
+            {
+                "room": {
+                    "timeline": {
+                        "types": [EventTypes.Message],
+                        "org.matrix.not_labels": ["#fun"],
+                    }
+                }
+            }
+        )
+
+        events = self._test_sync_filter_labels(sync_filter)
+
+        self.assertEqual(len(events), 3, [event["content"] for event in events])
+        self.assertEqual(events[0]["content"]["body"], "without label", events[0])
+        self.assertEqual(events[1]["content"]["body"], "with wrong label", events[1])
+        self.assertEqual(
+            events[2]["content"]["body"], "with two wrong labels", events[2]
+        )
+
+    def test_sync_filter_labels_not_labels(self):
+        """Test that we can filter by both a label and the absence of another label."""
+        sync_filter = json.dumps(
+            {
+                "room": {
+                    "timeline": {
+                        "types": [EventTypes.Message],
+                        "org.matrix.labels": ["#work"],
+                        "org.matrix.not_labels": ["#notfun"],
+                    }
+                }
+            }
+        )
+
+        events = self._test_sync_filter_labels(sync_filter)
+
+        self.assertEqual(len(events), 1, [event["content"] for event in events])
+        self.assertEqual(events[0]["content"]["body"], "with wrong label", events[0])
+
+    def _test_sync_filter_labels(self, sync_filter):
+        user_id = self.register_user("kermit", "test")
+        tok = self.login("kermit", "test")
+
+        room_id = self.helper.create_room_as(user_id, tok=tok)
+
+        self.helper.send_event(
+            room_id=room_id,
+            type=EventTypes.Message,
+            content={
+                "msgtype": "m.text",
+                "body": "with right label",
+                EventContentFields.LABELS: ["#fun"],
+            },
+            tok=tok,
+        )
+
+        self.helper.send_event(
+            room_id=room_id,
+            type=EventTypes.Message,
+            content={"msgtype": "m.text", "body": "without label"},
+            tok=tok,
+        )
+
+        self.helper.send_event(
+            room_id=room_id,
+            type=EventTypes.Message,
+            content={
+                "msgtype": "m.text",
+                "body": "with wrong label",
+                EventContentFields.LABELS: ["#work"],
+            },
+            tok=tok,
+        )
+
+        self.helper.send_event(
+            room_id=room_id,
+            type=EventTypes.Message,
+            content={
+                "msgtype": "m.text",
+                "body": "with two wrong labels",
+                EventContentFields.LABELS: ["#work", "#notfun"],
+            },
+            tok=tok,
+        )
+
+        self.helper.send_event(
+            room_id=room_id,
+            type=EventTypes.Message,
+            content={
+                "msgtype": "m.text",
+                "body": "with right label",
+                EventContentFields.LABELS: ["#fun"],
+            },
+            tok=tok,
+        )
+
+        request, channel = self.make_request(
+            "GET", "/sync?filter=%s" % sync_filter, access_token=tok
+        )
+        self.render(request)
+        self.assertEqual(channel.code, 200, channel.result)
+
+        return channel.json_body["rooms"]["join"][room_id]["timeline"]["events"]
+
+
 class SyncTypingTests(unittest.HomeserverTestCase):
 
     servlets = [
diff --git a/tests/server.py b/tests/server.py
index e397ebe8fa..f878aeaada 100644
--- a/tests/server.py
+++ b/tests/server.py
@@ -161,7 +161,11 @@ def make_request(
         path = path.encode("ascii")
 
     # Decorate it to be the full path, if we're using shorthand
-    if shorthand and not path.startswith(b"/_matrix"):
+    if (
+        shorthand
+        and not path.startswith(b"/_matrix")
+        and not path.startswith(b"/_synapse")
+    ):
         path = b"/_matrix/client/r0/" + path
         path = path.replace(b"//", b"/")
 
@@ -391,11 +395,24 @@ class FakeTransport(object):
             self.disconnecting = True
             if self._protocol:
                 self._protocol.connectionLost(reason)
-            self.disconnected = True
+
+            # if we still have data to write, delay until that is done
+            if self.buffer:
+                logger.info(
+                    "FakeTransport: Delaying disconnect until buffer is flushed"
+                )
+            else:
+                self.disconnected = True
 
     def abortConnection(self):
         logger.info("FakeTransport: abortConnection()")
-        self.loseConnection()
+
+        if not self.disconnecting:
+            self.disconnecting = True
+            if self._protocol:
+                self._protocol.connectionLost(None)
+
+        self.disconnected = True
 
     def pauseProducing(self):
         if not self.producer:
@@ -426,6 +443,9 @@ class FakeTransport(object):
             self._reactor.callLater(0.0, _produce)
 
     def write(self, byt):
+        if self.disconnecting:
+            raise Exception("Writing to disconnecting FakeTransport")
+
         self.buffer = self.buffer + byt
 
         # always actually do the write asynchronously. Some protocols (notably the
@@ -470,6 +490,10 @@ class FakeTransport(object):
         if self.buffer and self.autoflush:
             self._reactor.callLater(0.0, self.flush)
 
+        if not self.buffer and self.disconnecting:
+            logger.info("FakeTransport: Buffer now empty, completing disconnect")
+            self.disconnected = True
+
 
 def connect_client(reactor: IReactorTCP, client_id: int) -> AccumulatingProtocol:
     """
diff --git a/tests/storage/test__base.py b/tests/storage/test__base.py
index dd49a14524..9b81b536f5 100644
--- a/tests/storage/test__base.py
+++ b/tests/storage/test__base.py
@@ -197,7 +197,7 @@ class CacheDecoratorTestCase(unittest.TestCase):
 
         a.func.prefill(("foo",), ObservableDeferred(d))
 
-        self.assertEquals(a.func("foo"), d.result)
+        self.assertEquals(a.func("foo").result, d.result)
         self.assertEquals(callcount[0], 0)
 
     @defer.inlineCallbacks
diff --git a/tests/storage/test_devices.py b/tests/storage/test_devices.py
index 3cc18f9f1c..6f8d990959 100644
--- a/tests/storage/test_devices.py
+++ b/tests/storage/test_devices.py
@@ -72,7 +72,7 @@ class DeviceStoreTestCase(tests.unittest.TestCase):
         )
 
     @defer.inlineCallbacks
-    def test_get_devices_by_remote(self):
+    def test_get_device_updates_by_remote(self):
         device_ids = ["device_id1", "device_id2"]
 
         # Add two device updates with a single stream_id
@@ -81,7 +81,7 @@ class DeviceStoreTestCase(tests.unittest.TestCase):
         )
 
         # Get all device updates ever meant for this remote
-        now_stream_id, device_updates = yield self.store.get_devices_by_remote(
+        now_stream_id, device_updates = yield self.store.get_device_updates_by_remote(
             "somehost", -1, limit=100
         )
 
@@ -89,7 +89,7 @@ class DeviceStoreTestCase(tests.unittest.TestCase):
         self._check_devices_in_updates(device_ids, device_updates)
 
     @defer.inlineCallbacks
-    def test_get_devices_by_remote_limited(self):
+    def test_get_device_updates_by_remote_limited(self):
         # Test breaking the update limit in 1, 101, and 1 device_id segments
 
         # first add one device
@@ -115,20 +115,20 @@ class DeviceStoreTestCase(tests.unittest.TestCase):
         #
 
         # first we should get a single update
-        now_stream_id, device_updates = yield self.store.get_devices_by_remote(
+        now_stream_id, device_updates = yield self.store.get_device_updates_by_remote(
             "someotherhost", -1, limit=100
         )
         self._check_devices_in_updates(device_ids1, device_updates)
 
         # Then we should get an empty list back as the 101 devices broke the limit
-        now_stream_id, device_updates = yield self.store.get_devices_by_remote(
+        now_stream_id, device_updates = yield self.store.get_device_updates_by_remote(
             "someotherhost", now_stream_id, limit=100
         )
         self.assertEqual(len(device_updates), 0)
 
         # The 101 devices should've been cleared, so we should now just get one device
         # update
-        now_stream_id, device_updates = yield self.store.get_devices_by_remote(
+        now_stream_id, device_updates = yield self.store.get_device_updates_by_remote(
             "someotherhost", now_stream_id, limit=100
         )
         self._check_devices_in_updates(device_ids3, device_updates)
@@ -137,7 +137,9 @@ class DeviceStoreTestCase(tests.unittest.TestCase):
         """Check that an specific device ids exist in a list of device update EDUs"""
         self.assertEqual(len(device_updates), len(expected_device_ids))
 
-        received_device_ids = {update["device_id"] for update in device_updates}
+        received_device_ids = {
+            update["device_id"] for edu_type, update in device_updates
+        }
         self.assertEqual(received_device_ids, set(expected_device_ids))
 
     @defer.inlineCallbacks
diff --git a/tests/storage/test_e2e_room_keys.py b/tests/storage/test_e2e_room_keys.py
new file mode 100644
index 0000000000..d128fde441
--- /dev/null
+++ b/tests/storage/test_e2e_room_keys.py
@@ -0,0 +1,75 @@
+# -*- coding: utf-8 -*-
+# Copyright 2019 The Matrix.org Foundation C.I.C.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from tests import unittest
+
+# sample room_key data for use in the tests
+room_key = {
+    "first_message_index": 1,
+    "forwarded_count": 1,
+    "is_verified": False,
+    "session_data": "SSBBTSBBIEZJU0gK",
+}
+
+
+class E2eRoomKeysHandlerTestCase(unittest.HomeserverTestCase):
+    def make_homeserver(self, reactor, clock):
+        hs = self.setup_test_homeserver("server", http_client=None)
+        self.store = hs.get_datastore()
+        return hs
+
+    def test_room_keys_version_delete(self):
+        # test that deleting a room key backup deletes the keys
+        version1 = self.get_success(
+            self.store.create_e2e_room_keys_version(
+                "user_id", {"algorithm": "rot13", "auth_data": {}}
+            )
+        )
+
+        self.get_success(
+            self.store.set_e2e_room_key(
+                "user_id", version1, "room", "session", room_key
+            )
+        )
+
+        version2 = self.get_success(
+            self.store.create_e2e_room_keys_version(
+                "user_id", {"algorithm": "rot13", "auth_data": {}}
+            )
+        )
+
+        self.get_success(
+            self.store.set_e2e_room_key(
+                "user_id", version2, "room", "session", room_key
+            )
+        )
+
+        # make sure the keys were stored properly
+        keys = self.get_success(self.store.get_e2e_room_keys("user_id", version1))
+        self.assertEqual(len(keys["rooms"]), 1)
+
+        keys = self.get_success(self.store.get_e2e_room_keys("user_id", version2))
+        self.assertEqual(len(keys["rooms"]), 1)
+
+        # delete version1
+        self.get_success(self.store.delete_e2e_room_keys_version("user_id", version1))
+
+        # make sure the key from version1 is gone, and the key from version2 is
+        # still there
+        keys = self.get_success(self.store.get_e2e_room_keys("user_id", version1))
+        self.assertEqual(len(keys["rooms"]), 0)
+
+        keys = self.get_success(self.store.get_e2e_room_keys("user_id", version2))
+        self.assertEqual(len(keys["rooms"]), 1)
diff --git a/tests/storage/test_redaction.py b/tests/storage/test_redaction.py
index 427d3c49c5..4561c3e383 100644
--- a/tests/storage/test_redaction.py
+++ b/tests/storage/test_redaction.py
@@ -39,6 +39,7 @@ class RedactionTestCase(unittest.HomeserverTestCase):
 
     def prepare(self, reactor, clock, hs):
         self.store = hs.get_datastore()
+        self.storage = hs.get_storage()
         self.event_builder_factory = hs.get_event_builder_factory()
         self.event_creation_handler = hs.get_event_creation_handler()
 
@@ -73,7 +74,7 @@ class RedactionTestCase(unittest.HomeserverTestCase):
             self.event_creation_handler.create_new_client_event(builder)
         )
 
-        self.get_success(self.store.persist_event(event, context))
+        self.get_success(self.storage.persistence.persist_event(event, context))
 
         return event
 
@@ -95,7 +96,7 @@ class RedactionTestCase(unittest.HomeserverTestCase):
             self.event_creation_handler.create_new_client_event(builder)
         )
 
-        self.get_success(self.store.persist_event(event, context))
+        self.get_success(self.storage.persistence.persist_event(event, context))
 
         return event
 
@@ -116,7 +117,7 @@ class RedactionTestCase(unittest.HomeserverTestCase):
             self.event_creation_handler.create_new_client_event(builder)
         )
 
-        self.get_success(self.store.persist_event(event, context))
+        self.get_success(self.storage.persistence.persist_event(event, context))
 
         return event
 
@@ -263,7 +264,7 @@ class RedactionTestCase(unittest.HomeserverTestCase):
             )
         )
 
-        self.get_success(self.store.persist_event(event_1, context_1))
+        self.get_success(self.storage.persistence.persist_event(event_1, context_1))
 
         event_2, context_2 = self.get_success(
             self.event_creation_handler.create_new_client_event(
@@ -282,7 +283,7 @@ class RedactionTestCase(unittest.HomeserverTestCase):
                 )
             )
         )
-        self.get_success(self.store.persist_event(event_2, context_2))
+        self.get_success(self.storage.persistence.persist_event(event_2, context_2))
 
         # fetch one of the redactions
         fetched = self.get_success(self.store.get_event(redaction_event_id1))
diff --git a/tests/storage/test_room.py b/tests/storage/test_room.py
index 1bee45706f..3ddaa151fe 100644
--- a/tests/storage/test_room.py
+++ b/tests/storage/test_room.py
@@ -62,6 +62,7 @@ class RoomEventsStoreTestCase(unittest.TestCase):
         # Room events need the full datastore, for persist_event() and
         # get_room_state()
         self.store = hs.get_datastore()
+        self.storage = hs.get_storage()
         self.event_factory = hs.get_event_factory()
 
         self.room = RoomID.from_string("!abcde:test")
@@ -72,7 +73,7 @@ class RoomEventsStoreTestCase(unittest.TestCase):
 
     @defer.inlineCallbacks
     def inject_room_event(self, **kwargs):
-        yield self.store.persist_event(
+        yield self.storage.persistence.persist_event(
             self.event_factory.create_event(room_id=self.room.to_string(), **kwargs)
         )
 
diff --git a/tests/storage/test_roommember.py b/tests/storage/test_roommember.py
index 447a3c6ffb..9ddd17f73d 100644
--- a/tests/storage/test_roommember.py
+++ b/tests/storage/test_roommember.py
@@ -44,6 +44,7 @@ class RoomMemberStoreTestCase(unittest.HomeserverTestCase):
         # We can't test the RoomMemberStore on its own without the other event
         # storage logic
         self.store = hs.get_datastore()
+        self.storage = hs.get_storage()
         self.event_builder_factory = hs.get_event_builder_factory()
         self.event_creation_handler = hs.get_event_creation_handler()
 
@@ -70,7 +71,7 @@ class RoomMemberStoreTestCase(unittest.HomeserverTestCase):
             self.event_creation_handler.create_new_client_event(builder)
         )
 
-        self.get_success(self.store.persist_event(event, context))
+        self.get_success(self.storage.persistence.persist_event(event, context))
 
         return event
 
diff --git a/tests/storage/test_state.py b/tests/storage/test_state.py
index 5c2cf3c2db..43200654f1 100644
--- a/tests/storage/test_state.py
+++ b/tests/storage/test_state.py
@@ -34,6 +34,8 @@ class StateStoreTestCase(tests.unittest.TestCase):
         hs = yield tests.utils.setup_test_homeserver(self.addCleanup)
 
         self.store = hs.get_datastore()
+        self.storage = hs.get_storage()
+        self.state_datastore = self.store
         self.event_builder_factory = hs.get_event_builder_factory()
         self.event_creation_handler = hs.get_event_creation_handler()
 
@@ -63,7 +65,7 @@ class StateStoreTestCase(tests.unittest.TestCase):
             builder
         )
 
-        yield self.store.persist_event(event, context)
+        yield self.storage.persistence.persist_event(event, context)
 
         return event
 
@@ -82,7 +84,7 @@ class StateStoreTestCase(tests.unittest.TestCase):
             self.room, self.u_alice, EventTypes.Name, "", {"name": "test room"}
         )
 
-        state_group_map = yield self.store.get_state_groups_ids(
+        state_group_map = yield self.storage.state.get_state_groups_ids(
             self.room, [e2.event_id]
         )
         self.assertEqual(len(state_group_map), 1)
@@ -101,7 +103,9 @@ class StateStoreTestCase(tests.unittest.TestCase):
             self.room, self.u_alice, EventTypes.Name, "", {"name": "test room"}
         )
 
-        state_group_map = yield self.store.get_state_groups(self.room, [e2.event_id])
+        state_group_map = yield self.storage.state.get_state_groups(
+            self.room, [e2.event_id]
+        )
         self.assertEqual(len(state_group_map), 1)
         state_list = list(state_group_map.values())[0]
 
@@ -141,7 +145,7 @@ class StateStoreTestCase(tests.unittest.TestCase):
         )
 
         # check we get the full state as of the final event
-        state = yield self.store.get_state_for_event(e5.event_id)
+        state = yield self.storage.state.get_state_for_event(e5.event_id)
 
         self.assertIsNotNone(e4)
 
@@ -157,21 +161,21 @@ class StateStoreTestCase(tests.unittest.TestCase):
         )
 
         # check we can filter to the m.room.name event (with a '' state key)
-        state = yield self.store.get_state_for_event(
+        state = yield self.storage.state.get_state_for_event(
             e5.event_id, StateFilter.from_types([(EventTypes.Name, "")])
         )
 
         self.assertStateMapEqual({(e2.type, e2.state_key): e2}, state)
 
         # check we can filter to the m.room.name event (with a wildcard None state key)
-        state = yield self.store.get_state_for_event(
+        state = yield self.storage.state.get_state_for_event(
             e5.event_id, StateFilter.from_types([(EventTypes.Name, None)])
         )
 
         self.assertStateMapEqual({(e2.type, e2.state_key): e2}, state)
 
         # check we can grab the m.room.member events (with a wildcard None state key)
-        state = yield self.store.get_state_for_event(
+        state = yield self.storage.state.get_state_for_event(
             e5.event_id, StateFilter.from_types([(EventTypes.Member, None)])
         )
 
@@ -181,7 +185,7 @@ class StateStoreTestCase(tests.unittest.TestCase):
 
         # check we can grab a specific room member without filtering out the
         # other event types
-        state = yield self.store.get_state_for_event(
+        state = yield self.storage.state.get_state_for_event(
             e5.event_id,
             state_filter=StateFilter(
                 types={EventTypes.Member: {self.u_alice.to_string()}},
@@ -199,7 +203,7 @@ class StateStoreTestCase(tests.unittest.TestCase):
         )
 
         # check that we can grab everything except members
-        state = yield self.store.get_state_for_event(
+        state = yield self.storage.state.get_state_for_event(
             e5.event_id,
             state_filter=StateFilter(
                 types={EventTypes.Member: set()}, include_others=True
@@ -215,13 +219,18 @@ class StateStoreTestCase(tests.unittest.TestCase):
         #######################################################
 
         room_id = self.room.to_string()
-        group_ids = yield self.store.get_state_groups_ids(room_id, [e5.event_id])
+        group_ids = yield self.storage.state.get_state_groups_ids(
+            room_id, [e5.event_id]
+        )
         group = list(group_ids.keys())[0]
 
         # test _get_state_for_group_using_cache correctly filters out members
         # with types=[]
-        (state_dict, is_all) = yield self.store._get_state_for_group_using_cache(
-            self.store._state_group_cache,
+        (
+            state_dict,
+            is_all,
+        ) = yield self.state_datastore._get_state_for_group_using_cache(
+            self.state_datastore._state_group_cache,
             group,
             state_filter=StateFilter(
                 types={EventTypes.Member: set()}, include_others=True
@@ -237,8 +246,11 @@ class StateStoreTestCase(tests.unittest.TestCase):
             state_dict,
         )
 
-        (state_dict, is_all) = yield self.store._get_state_for_group_using_cache(
-            self.store._state_group_members_cache,
+        (
+            state_dict,
+            is_all,
+        ) = yield self.state_datastore._get_state_for_group_using_cache(
+            self.state_datastore._state_group_members_cache,
             group,
             state_filter=StateFilter(
                 types={EventTypes.Member: set()}, include_others=True
@@ -250,8 +262,11 @@ class StateStoreTestCase(tests.unittest.TestCase):
 
         # test _get_state_for_group_using_cache correctly filters in members
         # with wildcard types
-        (state_dict, is_all) = yield self.store._get_state_for_group_using_cache(
-            self.store._state_group_cache,
+        (
+            state_dict,
+            is_all,
+        ) = yield self.state_datastore._get_state_for_group_using_cache(
+            self.state_datastore._state_group_cache,
             group,
             state_filter=StateFilter(
                 types={EventTypes.Member: None}, include_others=True
@@ -267,8 +282,11 @@ class StateStoreTestCase(tests.unittest.TestCase):
             state_dict,
         )
 
-        (state_dict, is_all) = yield self.store._get_state_for_group_using_cache(
-            self.store._state_group_members_cache,
+        (
+            state_dict,
+            is_all,
+        ) = yield self.state_datastore._get_state_for_group_using_cache(
+            self.state_datastore._state_group_members_cache,
             group,
             state_filter=StateFilter(
                 types={EventTypes.Member: None}, include_others=True
@@ -287,8 +305,11 @@ class StateStoreTestCase(tests.unittest.TestCase):
 
         # test _get_state_for_group_using_cache correctly filters in members
         # with specific types
-        (state_dict, is_all) = yield self.store._get_state_for_group_using_cache(
-            self.store._state_group_cache,
+        (
+            state_dict,
+            is_all,
+        ) = yield self.state_datastore._get_state_for_group_using_cache(
+            self.state_datastore._state_group_cache,
             group,
             state_filter=StateFilter(
                 types={EventTypes.Member: {e5.state_key}}, include_others=True
@@ -304,8 +325,11 @@ class StateStoreTestCase(tests.unittest.TestCase):
             state_dict,
         )
 
-        (state_dict, is_all) = yield self.store._get_state_for_group_using_cache(
-            self.store._state_group_members_cache,
+        (
+            state_dict,
+            is_all,
+        ) = yield self.state_datastore._get_state_for_group_using_cache(
+            self.state_datastore._state_group_members_cache,
             group,
             state_filter=StateFilter(
                 types={EventTypes.Member: {e5.state_key}}, include_others=True
@@ -317,8 +341,11 @@ class StateStoreTestCase(tests.unittest.TestCase):
 
         # test _get_state_for_group_using_cache correctly filters in members
         # with specific types
-        (state_dict, is_all) = yield self.store._get_state_for_group_using_cache(
-            self.store._state_group_members_cache,
+        (
+            state_dict,
+            is_all,
+        ) = yield self.state_datastore._get_state_for_group_using_cache(
+            self.state_datastore._state_group_members_cache,
             group,
             state_filter=StateFilter(
                 types={EventTypes.Member: {e5.state_key}}, include_others=False
@@ -331,9 +358,11 @@ class StateStoreTestCase(tests.unittest.TestCase):
         #######################################################
         # deliberately remove e2 (room name) from the _state_group_cache
 
-        (is_all, known_absent, state_dict_ids) = self.store._state_group_cache.get(
-            group
-        )
+        (
+            is_all,
+            known_absent,
+            state_dict_ids,
+        ) = self.state_datastore._state_group_cache.get(group)
 
         self.assertEqual(is_all, True)
         self.assertEqual(known_absent, set())
@@ -346,18 +375,20 @@ class StateStoreTestCase(tests.unittest.TestCase):
         )
 
         state_dict_ids.pop((e2.type, e2.state_key))
-        self.store._state_group_cache.invalidate(group)
-        self.store._state_group_cache.update(
-            sequence=self.store._state_group_cache.sequence,
+        self.state_datastore._state_group_cache.invalidate(group)
+        self.state_datastore._state_group_cache.update(
+            sequence=self.state_datastore._state_group_cache.sequence,
             key=group,
             value=state_dict_ids,
             # list fetched keys so it knows it's partial
             fetched_keys=((e1.type, e1.state_key),),
         )
 
-        (is_all, known_absent, state_dict_ids) = self.store._state_group_cache.get(
-            group
-        )
+        (
+            is_all,
+            known_absent,
+            state_dict_ids,
+        ) = self.state_datastore._state_group_cache.get(group)
 
         self.assertEqual(is_all, False)
         self.assertEqual(known_absent, set([(e1.type, e1.state_key)]))
@@ -369,8 +400,11 @@ class StateStoreTestCase(tests.unittest.TestCase):
         # test _get_state_for_group_using_cache correctly filters out members
         # with types=[]
         room_id = self.room.to_string()
-        (state_dict, is_all) = yield self.store._get_state_for_group_using_cache(
-            self.store._state_group_cache,
+        (
+            state_dict,
+            is_all,
+        ) = yield self.state_datastore._get_state_for_group_using_cache(
+            self.state_datastore._state_group_cache,
             group,
             state_filter=StateFilter(
                 types={EventTypes.Member: set()}, include_others=True
@@ -381,8 +415,11 @@ class StateStoreTestCase(tests.unittest.TestCase):
         self.assertDictEqual({(e1.type, e1.state_key): e1.event_id}, state_dict)
 
         room_id = self.room.to_string()
-        (state_dict, is_all) = yield self.store._get_state_for_group_using_cache(
-            self.store._state_group_members_cache,
+        (
+            state_dict,
+            is_all,
+        ) = yield self.state_datastore._get_state_for_group_using_cache(
+            self.state_datastore._state_group_members_cache,
             group,
             state_filter=StateFilter(
                 types={EventTypes.Member: set()}, include_others=True
@@ -394,8 +431,11 @@ class StateStoreTestCase(tests.unittest.TestCase):
 
         # test _get_state_for_group_using_cache correctly filters in members
         # wildcard types
-        (state_dict, is_all) = yield self.store._get_state_for_group_using_cache(
-            self.store._state_group_cache,
+        (
+            state_dict,
+            is_all,
+        ) = yield self.state_datastore._get_state_for_group_using_cache(
+            self.state_datastore._state_group_cache,
             group,
             state_filter=StateFilter(
                 types={EventTypes.Member: None}, include_others=True
@@ -405,8 +445,11 @@ class StateStoreTestCase(tests.unittest.TestCase):
         self.assertEqual(is_all, False)
         self.assertDictEqual({(e1.type, e1.state_key): e1.event_id}, state_dict)
 
-        (state_dict, is_all) = yield self.store._get_state_for_group_using_cache(
-            self.store._state_group_members_cache,
+        (
+            state_dict,
+            is_all,
+        ) = yield self.state_datastore._get_state_for_group_using_cache(
+            self.state_datastore._state_group_members_cache,
             group,
             state_filter=StateFilter(
                 types={EventTypes.Member: None}, include_others=True
@@ -424,8 +467,11 @@ class StateStoreTestCase(tests.unittest.TestCase):
 
         # test _get_state_for_group_using_cache correctly filters in members
         # with specific types
-        (state_dict, is_all) = yield self.store._get_state_for_group_using_cache(
-            self.store._state_group_cache,
+        (
+            state_dict,
+            is_all,
+        ) = yield self.state_datastore._get_state_for_group_using_cache(
+            self.state_datastore._state_group_cache,
             group,
             state_filter=StateFilter(
                 types={EventTypes.Member: {e5.state_key}}, include_others=True
@@ -435,8 +481,11 @@ class StateStoreTestCase(tests.unittest.TestCase):
         self.assertEqual(is_all, False)
         self.assertDictEqual({(e1.type, e1.state_key): e1.event_id}, state_dict)
 
-        (state_dict, is_all) = yield self.store._get_state_for_group_using_cache(
-            self.store._state_group_members_cache,
+        (
+            state_dict,
+            is_all,
+        ) = yield self.state_datastore._get_state_for_group_using_cache(
+            self.state_datastore._state_group_members_cache,
             group,
             state_filter=StateFilter(
                 types={EventTypes.Member: {e5.state_key}}, include_others=True
@@ -448,8 +497,11 @@ class StateStoreTestCase(tests.unittest.TestCase):
 
         # test _get_state_for_group_using_cache correctly filters in members
         # with specific types
-        (state_dict, is_all) = yield self.store._get_state_for_group_using_cache(
-            self.store._state_group_cache,
+        (
+            state_dict,
+            is_all,
+        ) = yield self.state_datastore._get_state_for_group_using_cache(
+            self.state_datastore._state_group_cache,
             group,
             state_filter=StateFilter(
                 types={EventTypes.Member: {e5.state_key}}, include_others=False
@@ -459,8 +511,11 @@ class StateStoreTestCase(tests.unittest.TestCase):
         self.assertEqual(is_all, False)
         self.assertDictEqual({}, state_dict)
 
-        (state_dict, is_all) = yield self.store._get_state_for_group_using_cache(
-            self.store._state_group_members_cache,
+        (
+            state_dict,
+            is_all,
+        ) = yield self.state_datastore._get_state_for_group_using_cache(
+            self.state_datastore._state_group_members_cache,
             group,
             state_filter=StateFilter(
                 types={EventTypes.Member: {e5.state_key}}, include_others=False
diff --git a/tests/test_federation.py b/tests/test_federation.py
index a73f18f88e..7d82b58466 100644
--- a/tests/test_federation.py
+++ b/tests/test_federation.py
@@ -36,7 +36,8 @@ class MessageAcceptTests(unittest.TestCase):
         # Figure out what the most recent event is
         most_recent = self.successResultOf(
             maybeDeferred(
-                self.homeserver.datastore.get_latest_event_ids_in_room, self.room_id
+                self.homeserver.get_datastore().get_latest_event_ids_in_room,
+                self.room_id,
             )
         )[0]
 
@@ -58,7 +59,9 @@ class MessageAcceptTests(unittest.TestCase):
         )
 
         self.handler = self.homeserver.get_handlers().federation_handler
-        self.handler.do_auth = lambda *a, **b: succeed(True)
+        self.handler.do_auth = lambda origin, event, context, auth_events: succeed(
+            context
+        )
         self.client = self.homeserver.get_federation_client()
         self.client._check_sigs_and_hash_and_fetch = lambda dest, pdus, **k: succeed(
             pdus
@@ -75,7 +78,8 @@ class MessageAcceptTests(unittest.TestCase):
         self.assertEqual(
             self.successResultOf(
                 maybeDeferred(
-                    self.homeserver.datastore.get_latest_event_ids_in_room, self.room_id
+                    self.homeserver.get_datastore().get_latest_event_ids_in_room,
+                    self.room_id,
                 )
             )[0],
             "$join:test.serv",
@@ -97,7 +101,8 @@ class MessageAcceptTests(unittest.TestCase):
         # Figure out what the most recent event is
         most_recent = self.successResultOf(
             maybeDeferred(
-                self.homeserver.datastore.get_latest_event_ids_in_room, self.room_id
+                self.homeserver.get_datastore().get_latest_event_ids_in_room,
+                self.room_id,
             )
         )[0]
 
@@ -137,6 +142,6 @@ class MessageAcceptTests(unittest.TestCase):
 
         # Make sure the invalid event isn't there
         extrem = maybeDeferred(
-            self.homeserver.datastore.get_latest_event_ids_in_room, self.room_id
+            self.homeserver.get_datastore().get_latest_event_ids_in_room, self.room_id
         )
         self.assertEqual(self.successResultOf(extrem)[0], "$join:test.serv")
diff --git a/tests/test_phone_home.py b/tests/test_phone_home.py
new file mode 100644
index 0000000000..7657bddea5
--- /dev/null
+++ b/tests/test_phone_home.py
@@ -0,0 +1,51 @@
+# -*- coding: utf-8 -*-
+# Copyright 2019 Matrix.org Foundation C.I.C.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import resource
+
+import mock
+
+from synapse.app.homeserver import phone_stats_home
+
+from tests.unittest import HomeserverTestCase
+
+
+class PhoneHomeStatsTestCase(HomeserverTestCase):
+    def test_performance_frozen_clock(self):
+        """
+        If time doesn't move, don't error out.
+        """
+        past_stats = [
+            (self.hs.get_clock().time(), resource.getrusage(resource.RUSAGE_SELF))
+        ]
+        stats = {}
+        self.get_success(phone_stats_home(self.hs, stats, past_stats))
+        self.assertEqual(stats["cpu_average"], 0)
+
+    def test_performance_100(self):
+        """
+        1 second of usage over 1 second is 100% CPU usage.
+        """
+        real_res = resource.getrusage(resource.RUSAGE_SELF)
+        old_resource = mock.Mock(spec=real_res)
+        old_resource.ru_utime = real_res.ru_utime - 1
+        old_resource.ru_stime = real_res.ru_stime
+        old_resource.ru_maxrss = real_res.ru_maxrss
+
+        past_stats = [(self.hs.get_clock().time(), old_resource)]
+        stats = {}
+        self.reactor.advance(1)
+        self.get_success(phone_stats_home(self.hs, stats, past_stats))
+        self.assertApproximates(stats["cpu_average"], 100, tolerance=2.5)
diff --git a/tests/test_state.py b/tests/test_state.py
index 610ec9fb46..176535947a 100644
--- a/tests/test_state.py
+++ b/tests/test_state.py
@@ -21,6 +21,7 @@ from synapse.api.auth import Auth
 from synapse.api.constants import EventTypes, Membership
 from synapse.api.room_versions import RoomVersions
 from synapse.events import FrozenEvent
+from synapse.events.snapshot import EventContext
 from synapse.state import StateHandler, StateResolutionHandler
 
 from tests import unittest
@@ -158,10 +159,12 @@ class Graph(object):
 class StateTestCase(unittest.TestCase):
     def setUp(self):
         self.store = StateGroupStore()
+        storage = Mock(main=self.store, state=self.store)
         hs = Mock(
             spec_set=[
                 "config",
                 "get_datastore",
+                "get_storage",
                 "get_auth",
                 "get_state_handler",
                 "get_clock",
@@ -174,6 +177,7 @@ class StateTestCase(unittest.TestCase):
         hs.get_clock.return_value = MockClock()
         hs.get_auth.return_value = Auth(hs)
         hs.get_state_resolution_handler = lambda: StateResolutionHandler(hs)
+        hs.get_storage.return_value = storage
 
         self.state = StateHandler(hs)
         self.event_id = 0
@@ -195,16 +199,22 @@ class StateTestCase(unittest.TestCase):
 
         self.store.register_events(graph.walk())
 
-        context_store = {}
+        context_store = {}  # type: dict[str, EventContext]
 
         for event in graph.walk():
             context = yield self.state.compute_event_context(event)
             self.store.register_event_context(event, context)
             context_store[event.event_id] = context
 
-        prev_state_ids = yield context_store["D"].get_prev_state_ids(self.store)
+        ctx_c = context_store["C"]
+        ctx_d = context_store["D"]
+
+        prev_state_ids = yield ctx_d.get_prev_state_ids(self.store)
         self.assertEqual(2, len(prev_state_ids))
 
+        self.assertEqual(ctx_c.state_group, ctx_d.state_group_before_event)
+        self.assertEqual(ctx_d.state_group_before_event, ctx_d.state_group)
+
     @defer.inlineCallbacks
     def test_branch_basic_conflict(self):
         graph = Graph(
@@ -238,12 +248,19 @@ class StateTestCase(unittest.TestCase):
             self.store.register_event_context(event, context)
             context_store[event.event_id] = context
 
-        prev_state_ids = yield context_store["D"].get_prev_state_ids(self.store)
+        # C ends up winning the resolution between B and C
+
+        ctx_c = context_store["C"]
+        ctx_d = context_store["D"]
 
+        prev_state_ids = yield ctx_d.get_prev_state_ids(self.store)
         self.assertSetEqual(
             {"START", "A", "C"}, {e_id for e_id in prev_state_ids.values()}
         )
 
+        self.assertEqual(ctx_c.state_group, ctx_d.state_group_before_event)
+        self.assertEqual(ctx_d.state_group_before_event, ctx_d.state_group)
+
     @defer.inlineCallbacks
     def test_branch_have_banned_conflict(self):
         graph = Graph(
@@ -289,11 +306,18 @@ class StateTestCase(unittest.TestCase):
             self.store.register_event_context(event, context)
             context_store[event.event_id] = context
 
-        prev_state_ids = yield context_store["E"].get_prev_state_ids(self.store)
+        # C ends up winning the resolution between C and D because bans win over other
+        # changes
+
+        ctx_c = context_store["C"]
+        ctx_e = context_store["E"]
 
+        prev_state_ids = yield ctx_e.get_prev_state_ids(self.store)
         self.assertSetEqual(
             {"START", "A", "B", "C"}, {e for e in prev_state_ids.values()}
         )
+        self.assertEqual(ctx_c.state_group, ctx_e.state_group_before_event)
+        self.assertEqual(ctx_e.state_group_before_event, ctx_e.state_group)
 
     @defer.inlineCallbacks
     def test_branch_have_perms_conflict(self):
@@ -357,12 +381,20 @@ class StateTestCase(unittest.TestCase):
             self.store.register_event_context(event, context)
             context_store[event.event_id] = context
 
-        prev_state_ids = yield context_store["D"].get_prev_state_ids(self.store)
+        # B ends up winning the resolution between B and C because power levels
+        # win over other changes.
 
+        ctx_b = context_store["B"]
+        ctx_d = context_store["D"]
+
+        prev_state_ids = yield ctx_d.get_prev_state_ids(self.store)
         self.assertSetEqual(
             {"A1", "A2", "A3", "A5", "B"}, {e for e in prev_state_ids.values()}
         )
 
+        self.assertEqual(ctx_b.state_group, ctx_d.state_group_before_event)
+        self.assertEqual(ctx_d.state_group_before_event, ctx_d.state_group)
+
     def _add_depths(self, nodes, edges):
         def _get_depth(ev):
             node = nodes[ev]
@@ -387,13 +419,16 @@ class StateTestCase(unittest.TestCase):
 
         context = yield self.state.compute_event_context(event, old_state=old_state)
 
-        current_state_ids = yield context.get_current_state_ids(self.store)
+        prev_state_ids = yield context.get_prev_state_ids(self.store)
+        self.assertCountEqual((e.event_id for e in old_state), prev_state_ids.values())
 
-        self.assertEqual(
-            set(e.event_id for e in old_state), set(current_state_ids.values())
+        current_state_ids = yield context.get_current_state_ids(self.store)
+        self.assertCountEqual(
+            (e.event_id for e in old_state), current_state_ids.values()
         )
 
-        self.assertIsNotNone(context.state_group)
+        self.assertIsNotNone(context.state_group_before_event)
+        self.assertEqual(context.state_group_before_event, context.state_group)
 
     @defer.inlineCallbacks
     def test_annotate_with_old_state(self):
@@ -408,11 +443,18 @@ class StateTestCase(unittest.TestCase):
         context = yield self.state.compute_event_context(event, old_state=old_state)
 
         prev_state_ids = yield context.get_prev_state_ids(self.store)
+        self.assertCountEqual((e.event_id for e in old_state), prev_state_ids.values())
 
-        self.assertEqual(
-            set(e.event_id for e in old_state), set(prev_state_ids.values())
+        current_state_ids = yield context.get_current_state_ids(self.store)
+        self.assertCountEqual(
+            (e.event_id for e in old_state + [event]), current_state_ids.values()
         )
 
+        self.assertIsNotNone(context.state_group_before_event)
+        self.assertNotEqual(context.state_group_before_event, context.state_group)
+        self.assertEqual(context.state_group_before_event, context.prev_group)
+        self.assertEqual({("state", ""): event.event_id}, context.delta_ids)
+
     @defer.inlineCallbacks
     def test_trivial_annotate_message(self):
         prev_event_id = "prev_event_id"
diff --git a/tests/test_visibility.py b/tests/test_visibility.py
index 18f1a0035d..f7381b2885 100644
--- a/tests/test_visibility.py
+++ b/tests/test_visibility.py
@@ -14,6 +14,8 @@
 # limitations under the License.
 import logging
 
+from mock import Mock
+
 from twisted.internet import defer
 from twisted.internet.defer import succeed
 
@@ -36,6 +38,7 @@ class FilterEventsForServerTestCase(tests.unittest.TestCase):
         self.event_creation_handler = self.hs.get_event_creation_handler()
         self.event_builder_factory = self.hs.get_event_builder_factory()
         self.store = self.hs.get_datastore()
+        self.storage = self.hs.get_storage()
 
         yield create_room(self.hs, TEST_ROOM_ID, "@someone:ROOM")
 
@@ -62,7 +65,7 @@ class FilterEventsForServerTestCase(tests.unittest.TestCase):
             events_to_filter.append(evt)
 
         filtered = yield filter_events_for_server(
-            self.store, "test_server", events_to_filter
+            self.storage, "test_server", events_to_filter
         )
 
         # the result should be 5 redacted events, and 5 unredacted events.
@@ -100,7 +103,7 @@ class FilterEventsForServerTestCase(tests.unittest.TestCase):
 
         # ... and the filtering happens.
         filtered = yield filter_events_for_server(
-            self.store, "test_server", events_to_filter
+            self.storage, "test_server", events_to_filter
         )
 
         for i in range(0, len(events_to_filter)):
@@ -137,7 +140,7 @@ class FilterEventsForServerTestCase(tests.unittest.TestCase):
         event, context = yield self.event_creation_handler.create_new_client_event(
             builder
         )
-        yield self.hs.get_datastore().persist_event(event, context)
+        yield self.storage.persistence.persist_event(event, context)
         return event
 
     @defer.inlineCallbacks
@@ -159,7 +162,7 @@ class FilterEventsForServerTestCase(tests.unittest.TestCase):
             builder
         )
 
-        yield self.hs.get_datastore().persist_event(event, context)
+        yield self.storage.persistence.persist_event(event, context)
         return event
 
     @defer.inlineCallbacks
@@ -180,7 +183,7 @@ class FilterEventsForServerTestCase(tests.unittest.TestCase):
             builder
         )
 
-        yield self.hs.get_datastore().persist_event(event, context)
+        yield self.storage.persistence.persist_event(event, context)
         return event
 
     @defer.inlineCallbacks
@@ -257,6 +260,11 @@ class FilterEventsForServerTestCase(tests.unittest.TestCase):
 
         logger.info("Starting filtering")
         start = time.time()
+
+        storage = Mock()
+        storage.main = test_store
+        storage.state = test_store
+
         filtered = yield filter_events_for_server(
             test_store, "test_server", events_to_filter
         )
diff --git a/tests/util/caches/test_descriptors.py b/tests/util/caches/test_descriptors.py
index 5713870f48..39e360fe24 100644
--- a/tests/util/caches/test_descriptors.py
+++ b/tests/util/caches/test_descriptors.py
@@ -310,14 +310,14 @@ class DescriptorTestCase(unittest.TestCase):
 
         obj.mock.return_value = ["spam", "eggs"]
         r = obj.fn(1, 2)
-        self.assertEqual(r, ["spam", "eggs"])
+        self.assertEqual(r.result, ["spam", "eggs"])
         obj.mock.assert_called_once_with(1, 2)
         obj.mock.reset_mock()
 
         # a call with different params should call the mock again
         obj.mock.return_value = ["chips"]
         r = obj.fn(1, 3)
-        self.assertEqual(r, ["chips"])
+        self.assertEqual(r.result, ["chips"])
         obj.mock.assert_called_once_with(1, 3)
         obj.mock.reset_mock()
 
@@ -325,9 +325,9 @@ class DescriptorTestCase(unittest.TestCase):
         self.assertEqual(len(obj.fn.cache.cache), 3)
 
         r = obj.fn(1, 2)
-        self.assertEqual(r, ["spam", "eggs"])
+        self.assertEqual(r.result, ["spam", "eggs"])
         r = obj.fn(1, 3)
-        self.assertEqual(r, ["chips"])
+        self.assertEqual(r.result, ["chips"])
         obj.mock.assert_not_called()
 
     def test_cache_iterable_with_sync_exception(self):
diff --git a/tests/utils.py b/tests/utils.py
index 8cced4b7e8..7dc9bdc505 100644
--- a/tests/utils.py
+++ b/tests/utils.py
@@ -325,10 +325,16 @@ def setup_test_homeserver(
         if homeserverToUse.__name__ == "TestHomeServer":
             hs.setup_master()
     else:
+        # If we have been given an explicit datastore we probably want to mock
+        # out the DataStores somehow too. This all feels a bit wrong, but then
+        # mocking the stores feels wrong too.
+        datastores = Mock(datastore=datastore)
+
         hs = homeserverToUse(
             name,
             db_pool=None,
             datastore=datastore,
+            datastores=datastores,
             config=config,
             version_string="Synapse/tests",
             database_engine=db_engine,
@@ -646,7 +652,7 @@ def create_room(hs, room_id, creator_id):
         creator_id (str)
     """
 
-    store = hs.get_datastore()
+    persistence_store = hs.get_storage().persistence
     event_builder_factory = hs.get_event_builder_factory()
     event_creation_handler = hs.get_event_creation_handler()
 
@@ -663,4 +669,4 @@ def create_room(hs, room_id, creator_id):
 
     event, context = yield event_creation_handler.create_new_client_event(builder)
 
-    yield store.persist_event(event, context)
+    yield persistence_store.persist_event(event, context)
diff --git a/tox.ini b/tox.ini
index e3a53f340a..afe9bc909b 100644
--- a/tox.ini
+++ b/tox.ini
@@ -114,16 +114,16 @@ skip_install = True
 basepython = python3.6
 deps =
     flake8
-    black==19.3b0  # We pin so that our tests don't start failing on new releases of black.
+    black==19.10b0  # We pin so that our tests don't start failing on new releases of black.
 commands =
     python -m black --check --diff .
-    /bin/sh -c "flake8 synapse tests scripts scripts-dev scripts/hash_password scripts/register_new_matrix_user scripts/synapse_port_db synctl {env:PEP8SUFFIX:}"
+    /bin/sh -c "flake8 synapse tests scripts scripts-dev synctl {env:PEP8SUFFIX:}"
     {toxinidir}/scripts-dev/config-lint.sh
 
 [testenv:check_isort]
 skip_install = True
 deps = isort
-commands = /bin/sh -c "isort -c -df -sp setup.cfg -rc synapse tests"
+commands = /bin/sh -c "isort -c -df -sp setup.cfg -rc synapse tests scripts-dev scripts"
 
 [testenv:check-newsfragment]
 skip_install = True
@@ -167,6 +167,6 @@ deps =
 env =
     MYPYPATH = stubs/
 extras = all
-commands = mypy --show-traceback --check-untyped-defs --show-error-codes --follow-imports=normal \
+commands = mypy \
             synapse/logging/ \
             synapse/config/