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authorAndrew Morgan <andrew@amorgan.xyz>2019-09-11 10:58:43 +0100
committerAndrew Morgan <andrew@amorgan.xyz>2019-09-11 10:58:43 +0100
commitb4520ea4315ed45a1f8f4e19a68d4f3cf4a2d3e7 (patch)
tree0d82cd77eb3d156c5036b9fd6bc534b63840ebdc
parentid_access_token -> access_token in query params (diff)
parentRemove origin parameter from add_display_name_to_third_party_invite and add p... (diff)
downloadsynapse-b4520ea4315ed45a1f8f4e19a68d4f3cf4a2d3e7.tar.xz
Merge branch 'develop' of github.com:matrix-org/synapse into anoa/v2_lookup
-rw-r--r--UPGRADE.rst63
-rw-r--r--changelog.d/5835.feature1
-rw-r--r--changelog.d/5868.feature1
-rw-r--r--changelog.d/5875.misc1
-rw-r--r--changelog.d/5876.feature1
-rw-r--r--changelog.d/5892.misc1
-rw-r--r--changelog.d/5934.feature1
-rw-r--r--changelog.d/5940.feature1
-rw-r--r--changelog.d/5964.feature1
-rw-r--r--changelog.d/5969.feature1
-rw-r--r--changelog.d/5971.bugfix1
-rw-r--r--changelog.d/5975.misc1
-rw-r--r--changelog.d/5980.feature1
-rw-r--r--changelog.d/5981.feature1
-rw-r--r--changelog.d/5982.bugfix1
-rw-r--r--changelog.d/5983.feature1
-rw-r--r--changelog.d/5984.bugfix1
-rw-r--r--changelog.d/5986.feature1
-rw-r--r--changelog.d/5988.bugfix1
-rw-r--r--changelog.d/5991.bugfix1
-rw-r--r--changelog.d/5993.feature1
-rw-r--r--changelog.d/5994.feature1
-rw-r--r--changelog.d/5995.bugfix1
-rw-r--r--changelog.d/5998.bugfix1
-rw-r--r--changelog.d/6003.misc1
-rw-r--r--changelog.d/6004.bugfix1
-rw-r--r--changelog.d/6005.feature1
-rw-r--r--changelog.d/6010.misc1
-rw-r--r--changelog.d/6011.feature1
-rwxr-xr-xcontrib/cmdclient/console.py7
-rw-r--r--docs/room_and_user_statistics.md62
-rw-r--r--docs/sample_config.yaml73
-rw-r--r--synapse/app/client_reader.py2
-rw-r--r--synapse/config/emailconfig.py122
-rw-r--r--synapse/config/metrics.py31
-rw-r--r--synapse/config/registration.py36
-rw-r--r--synapse/config/server.py17
-rw-r--r--synapse/config/stats.py13
-rw-r--r--synapse/event_auth.py10
-rw-r--r--synapse/federation/federation_server.py4
-rw-r--r--synapse/federation/sender/transaction_manager.py13
-rw-r--r--synapse/federation/transport/server.py8
-rw-r--r--synapse/federation/units.py3
-rw-r--r--synapse/handlers/account_validity.py12
-rw-r--r--synapse/handlers/auth.py45
-rw-r--r--synapse/handlers/devicemessage.py5
-rw-r--r--synapse/handlers/federation.py7
-rw-r--r--synapse/handlers/identity.py338
-rw-r--r--synapse/handlers/register.py62
-rw-r--r--synapse/handlers/stats.py309
-rw-r--r--synapse/http/client.py87
-rw-r--r--synapse/http/matrixfederationclient.py1
-rw-r--r--synapse/http/server.py13
-rw-r--r--synapse/http/servlet.py6
-rw-r--r--synapse/logging/opentracing.py114
-rw-r--r--synapse/metrics/__init__.py12
-rw-r--r--synapse/push/httppusher.py13
-rw-r--r--synapse/push/mailer.py83
-rw-r--r--synapse/push/pusher.py17
-rw-r--r--synapse/replication/http/_base.py21
-rw-r--r--synapse/replication/http/register.py21
-rw-r--r--synapse/res/templates/password_reset.html2
-rw-r--r--synapse/res/templates/password_reset.txt4
-rw-r--r--synapse/res/templates/password_reset_failure.html4
-rw-r--r--synapse/res/templates/registration.html11
-rw-r--r--synapse/res/templates/registration.txt10
-rw-r--r--synapse/res/templates/registration_failure.html6
-rw-r--r--synapse/res/templates/registration_success.html6
-rw-r--r--synapse/rest/__init__.py2
-rw-r--r--synapse/rest/client/v2_alpha/_base.py2
-rw-r--r--synapse/rest/client/v2_alpha/account.py307
-rw-r--r--synapse/rest/client/v2_alpha/register.py198
-rw-r--r--synapse/rest/client/versions.py8
-rw-r--r--synapse/storage/devices.py2
-rw-r--r--synapse/storage/events.py108
-rw-r--r--synapse/storage/registration.py207
-rw-r--r--synapse/storage/roommember.py103
-rw-r--r--synapse/storage/schema/delta/56/redaction_censor.sql17
-rw-r--r--synapse/storage/schema/delta/56/stats_separated.sql152
-rw-r--r--synapse/storage/stats.py1038
-rw-r--r--tests/config/test_generate.py25
-rw-r--r--tests/config/test_load.py34
-rw-r--r--tests/handlers/test_register.py29
-rw-r--r--tests/handlers/test_stats.py643
-rw-r--r--tests/rest/client/v1/utils.py8
-rw-r--r--tests/storage/test_redaction.py77
-rw-r--r--tests/storage/test_roommember.py126
-rw-r--r--tests/test_metrics.py22
88 files changed, 3495 insertions, 1314 deletions
diff --git a/UPGRADE.rst b/UPGRADE.rst
index cf228c7c52..dddcd75fda 100644
--- a/UPGRADE.rst
+++ b/UPGRADE.rst
@@ -49,6 +49,56 @@ returned by the Client-Server API:
     # configured on port 443.
     curl -kv https://<host.name>/_matrix/client/versions 2>&1 | grep "Server:"
 
+Upgrading to v1.4.0
+===================
+
+Config options
+--------------
+
+**Note: Registration by email address or phone number will not work in this release unless
+some config options are changed from their defaults.**
+
+This is due to Synapse v1.4.0 now defaulting to sending registration and password reset tokens
+itself. This is for security reasons as well as putting less reliance on identity servers.
+However, currently Synapse only supports sending emails, and does not have support for
+phone-based password reset or account registration. If Synapse is configured to handle these on
+its own, phone-based password resets and registration will be disabled. For Synapse to send
+emails, the ``email`` block of the config must be filled out. If not, then password resets and
+registration via email will be disabled entirely.
+
+This release also deprecates the ``email.trust_identity_server_for_password_resets`` option and
+replaces it with the ``account_threepid_delegates`` dictionary. This option defines whether the
+homeserver should delegate an external server (typically an `identity server
+<https://matrix.org/docs/spec/identity_service/r0.2.1>`_) to handle sending password reset or
+registration messages via email and SMS.
+
+If ``email.trust_identity_server_for_password_resets`` is set to ``true``, and
+``account_threepid_delegates.email`` is not set, then the first entry in
+``trusted_third_party_id_servers`` will be used as the account threepid delegate for email.
+This is to ensure compatibility with existing Synapse installs that set up external server
+handling for these tasks before v1.4.0. If ``email.trust_identity_server_for_password_resets``
+is ``true`` and no trusted identity server domains are configured, Synapse will throw an error.
+
+If ``email.trust_identity_server_for_password_resets`` is ``false`` or absent and a threepid
+type in ``account_threepid_delegates`` is not set to a domain, then Synapse will attempt to
+send password reset and registration messages for that type.
+
+Email templates
+---------------
+
+If you have configured a custom template directory with the ``email.template_dir`` option, be
+aware that there are new templates regarding registration. ``registration.html`` and
+``registration.txt`` have been added and contain the content that is sent to a client upon
+registering via an email address.
+
+``registration_success.html`` and ``registration_failure.html`` are also new HTML templates
+that will be shown to the user when they click the link in their registration emai , either
+showing them a success or failure page (assuming a redirect URL is not configured).
+
+Synapse will expect these files to exist inside the configured template directory. To view the
+default templates, see `synapse/res/templates
+<https://github.com/matrix-org/synapse/tree/master/synapse/res/templates>`_.
+
 Upgrading to v1.2.0
 ===================
 
@@ -132,6 +182,19 @@ server for password resets, set ``trust_identity_server_for_password_resets`` to
 See the `sample configuration file <docs/sample_config.yaml>`_
 for more details on these settings.
 
+New email templates
+---------------
+Some new templates have been added to the default template directory for the purpose of the
+homeserver sending its own password reset emails. If you have configured a custom
+``template_dir`` in your Synapse config, these files will need to be added.
+
+``password_reset.html`` and ``password_reset.txt`` are HTML and plain text templates
+respectively that contain the contents of what will be emailed to the user upon attempting to
+reset their password via email. ``password_reset_success.html`` and
+``password_reset_failure.html`` are HTML files that the content of which (assuming no redirect
+URL is set) will be shown to the user after they attempt to click the link in the email sent
+to them.
+
 Upgrading to v0.99.0
 ====================
 
diff --git a/changelog.d/5835.feature b/changelog.d/5835.feature
new file mode 100644
index 0000000000..3e8bf5068d
--- /dev/null
+++ b/changelog.d/5835.feature
@@ -0,0 +1 @@
+Add the ability to send registration emails from the homeserver rather than delegating to an identity server.
diff --git a/changelog.d/5868.feature b/changelog.d/5868.feature
new file mode 100644
index 0000000000..69605c1ae1
--- /dev/null
+++ b/changelog.d/5868.feature
@@ -0,0 +1 @@
+Add `m.require_identity_server` key to `/versions`'s `unstable_features` section.
\ No newline at end of file
diff --git a/changelog.d/5875.misc b/changelog.d/5875.misc
new file mode 100644
index 0000000000..e188c28d2f
--- /dev/null
+++ b/changelog.d/5875.misc
@@ -0,0 +1 @@
+Deprecate the `trusted_third_party_id_servers` option.
\ No newline at end of file
diff --git a/changelog.d/5876.feature b/changelog.d/5876.feature
new file mode 100644
index 0000000000..df88193fbd
--- /dev/null
+++ b/changelog.d/5876.feature
@@ -0,0 +1 @@
+Replace `trust_identity_server_for_password_resets` config option with `account_threepid_delegates`.
\ No newline at end of file
diff --git a/changelog.d/5892.misc b/changelog.d/5892.misc
new file mode 100644
index 0000000000..939fe8c655
--- /dev/null
+++ b/changelog.d/5892.misc
@@ -0,0 +1 @@
+Compatibility with v2 Identity Service APIs other than /lookup.
\ No newline at end of file
diff --git a/changelog.d/5934.feature b/changelog.d/5934.feature
new file mode 100644
index 0000000000..eae969a52a
--- /dev/null
+++ b/changelog.d/5934.feature
@@ -0,0 +1 @@
+Redact events in the database that have been redacted for a month.
diff --git a/changelog.d/5940.feature b/changelog.d/5940.feature
new file mode 100644
index 0000000000..5b69b97fe7
--- /dev/null
+++ b/changelog.d/5940.feature
@@ -0,0 +1 @@
+Add the ability to send registration emails from the homeserver rather than delegating to an identity server.
\ No newline at end of file
diff --git a/changelog.d/5964.feature b/changelog.d/5964.feature
new file mode 100644
index 0000000000..273c9df026
--- /dev/null
+++ b/changelog.d/5964.feature
@@ -0,0 +1 @@
+Remove `bind_email` and `bind_msisdn` parameters from /register ala MSC2140.
\ No newline at end of file
diff --git a/changelog.d/5969.feature b/changelog.d/5969.feature
new file mode 100644
index 0000000000..cf603fa0c6
--- /dev/null
+++ b/changelog.d/5969.feature
@@ -0,0 +1 @@
+Replace `trust_identity_server_for_password_resets` config option with `account_threepid_delegates`.
diff --git a/changelog.d/5971.bugfix b/changelog.d/5971.bugfix
new file mode 100644
index 0000000000..9ea095103b
--- /dev/null
+++ b/changelog.d/5971.bugfix
@@ -0,0 +1 @@
+Fix room and user stats tracking.
diff --git a/changelog.d/5975.misc b/changelog.d/5975.misc
new file mode 100644
index 0000000000..5fcd229b89
--- /dev/null
+++ b/changelog.d/5975.misc
@@ -0,0 +1 @@
+Cleanup event auth type initialisation.
\ No newline at end of file
diff --git a/changelog.d/5980.feature b/changelog.d/5980.feature
new file mode 100644
index 0000000000..f25d8d81d9
--- /dev/null
+++ b/changelog.d/5980.feature
@@ -0,0 +1 @@
+Add POST /_matrix/client/r0/account/3pid/unbind endpoint from MSC2140 for unbinding a 3PID from an identity server without removing it from the homeserver user account.
\ No newline at end of file
diff --git a/changelog.d/5981.feature b/changelog.d/5981.feature
new file mode 100644
index 0000000000..e39514273d
--- /dev/null
+++ b/changelog.d/5981.feature
@@ -0,0 +1 @@
+Setting metrics_flags.known_servers to True in the configuration will publish the synapse_federation_known_servers metric over Prometheus. This represents the total number of servers your server knows about (i.e. is in rooms with), including itself.
diff --git a/changelog.d/5982.bugfix b/changelog.d/5982.bugfix
new file mode 100644
index 0000000000..3ea281a3a0
--- /dev/null
+++ b/changelog.d/5982.bugfix
@@ -0,0 +1 @@
+Include missing opentracing contexts in outbout replication requests.
diff --git a/changelog.d/5983.feature b/changelog.d/5983.feature
new file mode 100644
index 0000000000..aa23ee6dcd
--- /dev/null
+++ b/changelog.d/5983.feature
@@ -0,0 +1 @@
+Add minimum opentracing for client servlets.
diff --git a/changelog.d/5984.bugfix b/changelog.d/5984.bugfix
new file mode 100644
index 0000000000..3387bf82bb
--- /dev/null
+++ b/changelog.d/5984.bugfix
@@ -0,0 +1 @@
+Fix sending of EDUs when opentracing is enabled with an empty whitelist.
diff --git a/changelog.d/5986.feature b/changelog.d/5986.feature
new file mode 100644
index 0000000000..f56aec1b32
--- /dev/null
+++ b/changelog.d/5986.feature
@@ -0,0 +1 @@
+Trace replication send times.
diff --git a/changelog.d/5988.bugfix b/changelog.d/5988.bugfix
new file mode 100644
index 0000000000..5c3597cb53
--- /dev/null
+++ b/changelog.d/5988.bugfix
@@ -0,0 +1 @@
+Fix invalid references to None while opentracing if the log context slips.
diff --git a/changelog.d/5991.bugfix b/changelog.d/5991.bugfix
new file mode 100644
index 0000000000..5c3597cb53
--- /dev/null
+++ b/changelog.d/5991.bugfix
@@ -0,0 +1 @@
+Fix invalid references to None while opentracing if the log context slips.
diff --git a/changelog.d/5993.feature b/changelog.d/5993.feature
new file mode 100644
index 0000000000..3e8bf5068d
--- /dev/null
+++ b/changelog.d/5993.feature
@@ -0,0 +1 @@
+Add the ability to send registration emails from the homeserver rather than delegating to an identity server.
diff --git a/changelog.d/5994.feature b/changelog.d/5994.feature
new file mode 100644
index 0000000000..5b69b97fe7
--- /dev/null
+++ b/changelog.d/5994.feature
@@ -0,0 +1 @@
+Add the ability to send registration emails from the homeserver rather than delegating to an identity server.
\ No newline at end of file
diff --git a/changelog.d/5995.bugfix b/changelog.d/5995.bugfix
new file mode 100644
index 0000000000..e03ab98bc6
--- /dev/null
+++ b/changelog.d/5995.bugfix
@@ -0,0 +1 @@
+Return a M_MISSING_PARAM if `sid` is not provided to `/account/3pid`.
\ No newline at end of file
diff --git a/changelog.d/5998.bugfix b/changelog.d/5998.bugfix
new file mode 100644
index 0000000000..9ea095103b
--- /dev/null
+++ b/changelog.d/5998.bugfix
@@ -0,0 +1 @@
+Fix room and user stats tracking.
diff --git a/changelog.d/6003.misc b/changelog.d/6003.misc
new file mode 100644
index 0000000000..4152d05f87
--- /dev/null
+++ b/changelog.d/6003.misc
@@ -0,0 +1 @@
+Add opentracing span over HTTP push processing.
diff --git a/changelog.d/6004.bugfix b/changelog.d/6004.bugfix
new file mode 100644
index 0000000000..45c179c8fd
--- /dev/null
+++ b/changelog.d/6004.bugfix
@@ -0,0 +1 @@
+Only count real users when checking for auto-creation of auto-join room.
diff --git a/changelog.d/6005.feature b/changelog.d/6005.feature
new file mode 100644
index 0000000000..ed6491d3e4
--- /dev/null
+++ b/changelog.d/6005.feature
@@ -0,0 +1 @@
+The new Prometheus metric `synapse_build_info` exposes the Python version, OS version, and Synapse version of the running server.
diff --git a/changelog.d/6010.misc b/changelog.d/6010.misc
new file mode 100644
index 0000000000..0659f12ebd
--- /dev/null
+++ b/changelog.d/6010.misc
@@ -0,0 +1 @@
+Remove unused `origin` argument on FederationHandler.add_display_name_to_third_party_invite.
\ No newline at end of file
diff --git a/changelog.d/6011.feature b/changelog.d/6011.feature
new file mode 100644
index 0000000000..ad16acb12b
--- /dev/null
+++ b/changelog.d/6011.feature
@@ -0,0 +1 @@
+Use account_threepid_delegate.email and account_threepid_delegate.msisdn for validating threepid sessions.
\ No newline at end of file
diff --git a/contrib/cmdclient/console.py b/contrib/cmdclient/console.py
index af8f39c8c2..48da410d94 100755
--- a/contrib/cmdclient/console.py
+++ b/contrib/cmdclient/console.py
@@ -37,6 +37,8 @@ from signedjson.sign import verify_signed_json, SignatureVerifyException
 
 CONFIG_JSON = "cmdclient_config.json"
 
+# TODO: The concept of trusted identity servers has been deprecated. This option and checks
+#  should be removed
 TRUSTED_ID_SERVERS = ["localhost:8001"]
 
 
@@ -268,6 +270,7 @@ class SynapseCmd(cmd.Cmd):
 
     @defer.inlineCallbacks
     def _do_emailrequest(self, args):
+        # TODO: Update to use v2 Identity Service API endpoint
         url = (
             self._identityServerUrl()
             + "/_matrix/identity/api/v1/validate/email/requestToken"
@@ -302,6 +305,7 @@ class SynapseCmd(cmd.Cmd):
 
     @defer.inlineCallbacks
     def _do_emailvalidate(self, args):
+        # TODO: Update to use v2 Identity Service API endpoint
         url = (
             self._identityServerUrl()
             + "/_matrix/identity/api/v1/validate/email/submitToken"
@@ -330,6 +334,7 @@ class SynapseCmd(cmd.Cmd):
 
     @defer.inlineCallbacks
     def _do_3pidbind(self, args):
+        # TODO: Update to use v2 Identity Service API endpoint
         url = self._identityServerUrl() + "/_matrix/identity/api/v1/3pid/bind"
 
         json_res = yield self.http_client.do_request(
@@ -398,6 +403,7 @@ class SynapseCmd(cmd.Cmd):
     @defer.inlineCallbacks
     def _do_invite(self, roomid, userstring):
         if not userstring.startswith("@") and self._is_on("complete_usernames"):
+            # TODO: Update to use v2 Identity Service API endpoint
             url = self._identityServerUrl() + "/_matrix/identity/api/v1/lookup"
 
             json_res = yield self.http_client.do_request(
@@ -407,6 +413,7 @@ class SynapseCmd(cmd.Cmd):
             mxid = None
 
             if "mxid" in json_res and "signatures" in json_res:
+                # TODO: Update to use v2 Identity Service API endpoint
                 url = (
                     self._identityServerUrl()
                     + "/_matrix/identity/api/v1/pubkey/ed25519"
diff --git a/docs/room_and_user_statistics.md b/docs/room_and_user_statistics.md
new file mode 100644
index 0000000000..e1facb38d4
--- /dev/null
+++ b/docs/room_and_user_statistics.md
@@ -0,0 +1,62 @@
+Room and User Statistics
+========================
+
+Synapse maintains room and user statistics (as well as a cache of room state),
+in various tables. These can be used for administrative purposes but are also
+used when generating the public room directory.
+
+
+# Synapse Developer Documentation
+
+## High-Level Concepts
+
+### Definitions
+
+* **subject**: Something we are tracking stats about ā€“ currently a room or user.
+* **current row**: An entry for a subject in the appropriate current statistics
+    table. Each subject can have only one.
+* **historical row**: An entry for a subject in the appropriate historical
+    statistics table. Each subject can have any number of these.
+
+### Overview
+
+Stats are maintained as time series. There are two kinds of column:
+
+* absolute columns ā€“ where the value is correct for the time given by `end_ts`
+    in the stats row. (Imagine a line graph for these values)
+    * They can also be thought of as 'gauges' in Prometheus, if you are familiar.
+* per-slice columns ā€“ where the value corresponds to how many of the occurrences
+    occurred within the time slice given by `(end_ts āˆ’ bucket_size)ā€¦end_ts`
+    or `start_tsā€¦end_ts`. (Imagine a histogram for these values)
+
+Stats are maintained in two tables (for each type): current and historical.
+
+Current stats correspond to the present values. Each subject can only have one
+entry.
+
+Historical stats correspond to values in the past. Subjects may have multiple
+entries.
+
+## Concepts around the management of stats
+
+### Current rows
+
+Current rows contain the most up-to-date statistics for a room.
+They only contain absolute columns
+
+### Historical rows
+
+Historical rows can always be considered to be valid for the time slice and
+end time specified.
+
+* historical rows will not exist for every time slice ā€“ they will be omitted
+    if there were no changes. In this case, the following assumptions can be
+    made to interpolate/recreate missing rows:
+    - absolute fields have the same values as in the preceding row
+    - per-slice fields are zero (`0`)
+* historical rows will not be retained forever ā€“ rows older than a configurable
+    time will be purged.
+
+#### Purge
+
+The purging of historical rows is not yet implemented.
diff --git a/docs/sample_config.yaml b/docs/sample_config.yaml
index 43969bbb70..9b1ae58a27 100644
--- a/docs/sample_config.yaml
+++ b/docs/sample_config.yaml
@@ -306,6 +306,13 @@ listeners:
 #
 #allow_per_room_profiles: false
 
+# How long to keep redacted events in unredacted form in the database. After
+# this period redacted events get replaced with their redacted form in the DB.
+#
+# Defaults to `7d`. Set to `null` to disable.
+#
+redaction_retention_period: 7d
+
 
 ## TLS ##
 
@@ -891,10 +898,42 @@ uploads_path: "DATADIR/uploads"
 # Also defines the ID server which will be called when an account is
 # deactivated (one will be picked arbitrarily).
 #
+# Note: This option is deprecated. Since v0.99.4, Synapse has tracked which identity
+# server a 3PID has been bound to. For 3PIDs bound before then, Synapse runs a
+# background migration script, informing itself that the identity server all of its
+# 3PIDs have been bound to is likely one of the below.
+#
+# As of Synapse v1.4.0, all other functionality of this option has been deprecated, and
+# it is now solely used for the purposes of the background migration script, and can be
+# removed once it has run.
 #trusted_third_party_id_servers:
 #  - matrix.org
 #  - vector.im
 
+# Handle threepid (email/phone etc) registration and password resets through a set of
+# *trusted* identity servers. Note that this allows the configured identity server to
+# reset passwords for accounts!
+#
+# Be aware that if `email` is not set, and SMTP options have not been
+# configured in the email config block, registration and user password resets via
+# email will be globally disabled.
+#
+# Additionally, if `msisdn` is not set, registration and password resets via msisdn
+# will be disabled regardless. This is due to Synapse currently not supporting any
+# method of sending SMS messages on its own.
+#
+# To enable using an identity server for operations regarding a particular third-party
+# identifier type, set the value to the URL of that identity server as shown in the
+# examples below.
+#
+# Servers handling the these requests must answer the `/requestToken` endpoints defined
+# by the Matrix Identity Service API specification:
+# https://matrix.org/docs/spec/identity_service/latest
+#
+account_threepid_delegates:
+    #email: https://example.com     # Delegate email sending to matrix.org
+    #msisdn: http://localhost:8090  # Delegate SMS sending to this local process
+
 # Users who register on this homeserver will automatically be joined
 # to these rooms
 #
@@ -926,6 +965,16 @@ uploads_path: "DATADIR/uploads"
 #sentry:
 #    dsn: "..."
 
+# Flags to enable Prometheus metrics which are not suitable to be
+# enabled by default, either for performance reasons or limited use.
+#
+metrics_flags:
+    # Publish synapse_federation_known_servers, a g auge of the number of
+    # servers this homeserver knows about, including itself. May cause
+    # performance problems on large homeservers.
+    #
+    #known_servers: true
+
 # Whether or not to report anonymized homeserver usage statistics.
 # report_stats: true|false
 
@@ -1164,19 +1213,6 @@ password_config:
 #   #
 #   riot_base_url: "http://localhost/riot"
 #
-#   # Enable sending password reset emails via the configured, trusted
-#   # identity servers
-#   #
-#   # IMPORTANT! This will give a malicious or overtaken identity server
-#   # the ability to reset passwords for your users! Make absolutely sure
-#   # that you want to do this! It is strongly recommended that password
-#   # reset emails be sent by the homeserver instead
-#   #
-#   # If this option is set to false and SMTP options have not been
-#   # configured, resetting user passwords via email will be disabled
-#   #
-#   #trust_identity_server_for_password_resets: false
-#
 #   # Configure the time that a validation email or text message code
 #   # will expire after sending
 #   #
@@ -1208,11 +1244,22 @@ password_config:
 #   #password_reset_template_html: password_reset.html
 #   #password_reset_template_text: password_reset.txt
 #
+#   # Templates for registration emails sent by the homeserver
+#   #
+#   #registration_template_html: registration.html
+#   #registration_template_text: registration.txt
+#
 #   # Templates for password reset success and failure pages that a user
 #   # will see after attempting to reset their password
 #   #
 #   #password_reset_template_success_html: password_reset_success.html
 #   #password_reset_template_failure_html: password_reset_failure.html
+#
+#   # Templates for registration success and failure pages that a user
+#   # will see after attempting to register using an email or phone
+#   #
+#   #registration_template_success_html: registration_success.html
+#   #registration_template_failure_html: registration_failure.html
 
 
 #password_providers:
diff --git a/synapse/app/client_reader.py b/synapse/app/client_reader.py
index 86193d35a8..dbcc414c42 100644
--- a/synapse/app/client_reader.py
+++ b/synapse/app/client_reader.py
@@ -119,7 +119,7 @@ class ClientReaderServer(HomeServer):
                     KeyChangesServlet(self).register(resource)
                     VoipRestServlet(self).register(resource)
                     PushRuleRestServlet(self).register(resource)
-                    VersionsRestServlet().register(resource)
+                    VersionsRestServlet(self).register(resource)
 
                     resources.update({"/_matrix/client": resource})
 
diff --git a/synapse/config/emailconfig.py b/synapse/config/emailconfig.py
index f83c05df44..e5de768b0c 100644
--- a/synapse/config/emailconfig.py
+++ b/synapse/config/emailconfig.py
@@ -20,6 +20,7 @@ from __future__ import print_function
 # This file can't be called email.py because if it is, we cannot:
 import email.utils
 import os
+from enum import Enum
 
 import pkg_resources
 
@@ -74,19 +75,48 @@ class EmailConfig(Config):
             "renew_at"
         )
 
-        email_trust_identity_server_for_password_resets = email_config.get(
-            "trust_identity_server_for_password_resets", False
+        self.threepid_behaviour_email = (
+            # Have Synapse handle the email sending if account_threepid_delegates.email
+            # is not defined
+            # msisdn is currently always remote while Synapse does not support any method of
+            # sending SMS messages
+            ThreepidBehaviour.REMOTE
+            if self.account_threepid_delegate_email
+            else ThreepidBehaviour.LOCAL
         )
-        self.email_password_reset_behaviour = (
-            "remote" if email_trust_identity_server_for_password_resets else "local"
-        )
-        self.password_resets_were_disabled_due_to_email_config = False
-        if self.email_password_reset_behaviour == "local" and email_config == {}:
+        # Prior to Synapse v1.4.0, there was another option that defined whether Synapse would
+        # use an identity server to password reset tokens on its behalf. We now warn the user
+        # if they have this set and tell them to use the updated option, while using a default
+        # identity server in the process.
+        self.using_identity_server_from_trusted_list = False
+        if (
+            not self.account_threepid_delegate_email
+            and config.get("trust_identity_server_for_password_resets", False) is True
+        ):
+            # Use the first entry in self.trusted_third_party_id_servers instead
+            if self.trusted_third_party_id_servers:
+                # XXX: It's a little confusing that account_threepid_delegate_email is modified
+                # both in RegistrationConfig and here. We should factor this bit out
+                self.account_threepid_delegate_email = self.trusted_third_party_id_servers[
+                    0
+                ]
+                self.using_identity_server_from_trusted_list = True
+            else:
+                raise ConfigError(
+                    "Attempted to use an identity server from"
+                    '"trusted_third_party_id_servers" but it is empty.'
+                )
+
+        self.local_threepid_handling_disabled_due_to_email_config = False
+        if (
+            self.threepid_behaviour_email == ThreepidBehaviour.LOCAL
+            and email_config == {}
+        ):
             # We cannot warn the user this has happened here
             # Instead do so when a user attempts to reset their password
-            self.password_resets_were_disabled_due_to_email_config = True
+            self.local_threepid_handling_disabled_due_to_email_config = True
 
-            self.email_password_reset_behaviour = "off"
+            self.threepid_behaviour_email = ThreepidBehaviour.OFF
 
         # Get lifetime of a validation token in milliseconds
         self.email_validation_token_lifetime = self.parse_duration(
@@ -96,7 +126,7 @@ class EmailConfig(Config):
         if (
             self.email_enable_notifs
             or account_validity_renewal_enabled
-            or self.email_password_reset_behaviour == "local"
+            or self.threepid_behaviour_email == ThreepidBehaviour.LOCAL
         ):
             # make sure we can import the required deps
             import jinja2
@@ -106,7 +136,7 @@ class EmailConfig(Config):
             jinja2
             bleach
 
-        if self.email_password_reset_behaviour == "local":
+        if self.threepid_behaviour_email == ThreepidBehaviour.LOCAL:
             required = ["smtp_host", "smtp_port", "notif_from"]
 
             missing = []
@@ -125,28 +155,45 @@ class EmailConfig(Config):
                     % (", ".join(missing),)
                 )
 
-            # Templates for password reset emails
+            # These email templates have placeholders in them, and thus must be
+            # parsed using a templating engine during a request
             self.email_password_reset_template_html = email_config.get(
                 "password_reset_template_html", "password_reset.html"
             )
             self.email_password_reset_template_text = email_config.get(
                 "password_reset_template_text", "password_reset.txt"
             )
+            self.email_registration_template_html = email_config.get(
+                "registration_template_html", "registration.html"
+            )
+            self.email_registration_template_text = email_config.get(
+                "registration_template_text", "registration.txt"
+            )
             self.email_password_reset_template_failure_html = email_config.get(
                 "password_reset_template_failure_html", "password_reset_failure.html"
             )
-            # This template does not support any replaceable variables, so we will
-            # read it from the disk once during setup
+            self.email_registration_template_failure_html = email_config.get(
+                "registration_template_failure_html", "registration_failure.html"
+            )
+
+            # These templates do not support any placeholder variables, so we
+            # will read them from disk once during setup
             email_password_reset_template_success_html = email_config.get(
                 "password_reset_template_success_html", "password_reset_success.html"
             )
+            email_registration_template_success_html = email_config.get(
+                "registration_template_success_html", "registration_success.html"
+            )
 
             # Check templates exist
             for f in [
                 self.email_password_reset_template_html,
                 self.email_password_reset_template_text,
+                self.email_registration_template_html,
+                self.email_registration_template_text,
                 self.email_password_reset_template_failure_html,
                 email_password_reset_template_success_html,
+                email_registration_template_success_html,
             ]:
                 p = os.path.join(self.email_template_dir, f)
                 if not os.path.isfile(p):
@@ -156,9 +203,15 @@ class EmailConfig(Config):
             filepath = os.path.join(
                 self.email_template_dir, email_password_reset_template_success_html
             )
-            self.email_password_reset_template_success_html_content = self.read_file(
+            self.email_password_reset_template_success_html = self.read_file(
                 filepath, "email.password_reset_template_success_html"
             )
+            filepath = os.path.join(
+                self.email_template_dir, email_registration_template_success_html
+            )
+            self.email_registration_template_success_html_content = self.read_file(
+                filepath, "email.registration_template_success_html"
+            )
 
         if self.email_enable_notifs:
             required = [
@@ -239,19 +292,6 @@ class EmailConfig(Config):
         #   #
         #   riot_base_url: "http://localhost/riot"
         #
-        #   # Enable sending password reset emails via the configured, trusted
-        #   # identity servers
-        #   #
-        #   # IMPORTANT! This will give a malicious or overtaken identity server
-        #   # the ability to reset passwords for your users! Make absolutely sure
-        #   # that you want to do this! It is strongly recommended that password
-        #   # reset emails be sent by the homeserver instead
-        #   #
-        #   # If this option is set to false and SMTP options have not been
-        #   # configured, resetting user passwords via email will be disabled
-        #   #
-        #   #trust_identity_server_for_password_resets: false
-        #
         #   # Configure the time that a validation email or text message code
         #   # will expire after sending
         #   #
@@ -283,9 +323,35 @@ class EmailConfig(Config):
         #   #password_reset_template_html: password_reset.html
         #   #password_reset_template_text: password_reset.txt
         #
+        #   # Templates for registration emails sent by the homeserver
+        #   #
+        #   #registration_template_html: registration.html
+        #   #registration_template_text: registration.txt
+        #
         #   # Templates for password reset success and failure pages that a user
         #   # will see after attempting to reset their password
         #   #
         #   #password_reset_template_success_html: password_reset_success.html
         #   #password_reset_template_failure_html: password_reset_failure.html
+        #
+        #   # Templates for registration success and failure pages that a user
+        #   # will see after attempting to register using an email or phone
+        #   #
+        #   #registration_template_success_html: registration_success.html
+        #   #registration_template_failure_html: registration_failure.html
         """
+
+
+class ThreepidBehaviour(Enum):
+    """
+    Enum to define the behaviour of Synapse with regards to when it contacts an identity
+    server for 3pid registration and password resets
+
+    REMOTE = use an external server to send tokens
+    LOCAL = send tokens ourselves
+    OFF = disable registration via 3pid and password resets
+    """
+
+    REMOTE = "remote"
+    LOCAL = "local"
+    OFF = "off"
diff --git a/synapse/config/metrics.py b/synapse/config/metrics.py
index 3698441963..653b990e67 100644
--- a/synapse/config/metrics.py
+++ b/synapse/config/metrics.py
@@ -1,5 +1,6 @@
 # -*- coding: utf-8 -*-
 # Copyright 2015, 2016 OpenMarket 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 +14,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import attr
+
 from ._base import Config, ConfigError
 
 MISSING_SENTRY = """Missing sentry-sdk library. This is required to enable sentry
@@ -20,6 +23,18 @@ MISSING_SENTRY = """Missing sentry-sdk library. This is required to enable sentr
     """
 
 
+@attr.s
+class MetricsFlags(object):
+    known_servers = attr.ib(default=False, validator=attr.validators.instance_of(bool))
+
+    @classmethod
+    def all_off(cls):
+        """
+        Instantiate the flags with all options set to off.
+        """
+        return cls(**{x.name: False for x in attr.fields(cls)})
+
+
 class MetricsConfig(Config):
     def read_config(self, config, **kwargs):
         self.enable_metrics = config.get("enable_metrics", False)
@@ -27,6 +42,12 @@ class MetricsConfig(Config):
         self.metrics_port = config.get("metrics_port")
         self.metrics_bind_host = config.get("metrics_bind_host", "127.0.0.1")
 
+        if self.enable_metrics:
+            _metrics_config = config.get("metrics_flags") or {}
+            self.metrics_flags = MetricsFlags(**_metrics_config)
+        else:
+            self.metrics_flags = MetricsFlags.all_off()
+
         self.sentry_enabled = "sentry" in config
         if self.sentry_enabled:
             try:
@@ -58,6 +79,16 @@ class MetricsConfig(Config):
         #sentry:
         #    dsn: "..."
 
+        # Flags to enable Prometheus metrics which are not suitable to be
+        # enabled by default, either for performance reasons or limited use.
+        #
+        metrics_flags:
+            # Publish synapse_federation_known_servers, a g auge of the number of
+            # servers this homeserver knows about, including itself. May cause
+            # performance problems on large homeservers.
+            #
+            #known_servers: true
+
         # Whether or not to report anonymized homeserver usage statistics.
         """
 
diff --git a/synapse/config/registration.py b/synapse/config/registration.py
index e2bee3c116..9548560edb 100644
--- a/synapse/config/registration.py
+++ b/synapse/config/registration.py
@@ -99,6 +99,10 @@ class RegistrationConfig(Config):
         self.trusted_third_party_id_servers = config.get(
             "trusted_third_party_id_servers", ["matrix.org", "vector.im"]
         )
+        account_threepid_delegates = config.get("account_threepid_delegates") or {}
+        self.account_threepid_delegate_email = account_threepid_delegates.get("email")
+        self.account_threepid_delegate_msisdn = account_threepid_delegates.get("msisdn")
+
         self.default_identity_server = config.get("default_identity_server")
         self.allow_guest_access = config.get("allow_guest_access", False)
 
@@ -257,10 +261,42 @@ class RegistrationConfig(Config):
         # Also defines the ID server which will be called when an account is
         # deactivated (one will be picked arbitrarily).
         #
+        # Note: This option is deprecated. Since v0.99.4, Synapse has tracked which identity
+        # server a 3PID has been bound to. For 3PIDs bound before then, Synapse runs a
+        # background migration script, informing itself that the identity server all of its
+        # 3PIDs have been bound to is likely one of the below.
+        #
+        # As of Synapse v1.4.0, all other functionality of this option has been deprecated, and
+        # it is now solely used for the purposes of the background migration script, and can be
+        # removed once it has run.
         #trusted_third_party_id_servers:
         #  - matrix.org
         #  - vector.im
 
+        # Handle threepid (email/phone etc) registration and password resets through a set of
+        # *trusted* identity servers. Note that this allows the configured identity server to
+        # reset passwords for accounts!
+        #
+        # Be aware that if `email` is not set, and SMTP options have not been
+        # configured in the email config block, registration and user password resets via
+        # email will be globally disabled.
+        #
+        # Additionally, if `msisdn` is not set, registration and password resets via msisdn
+        # will be disabled regardless. This is due to Synapse currently not supporting any
+        # method of sending SMS messages on its own.
+        #
+        # To enable using an identity server for operations regarding a particular third-party
+        # identifier type, set the value to the URL of that identity server as shown in the
+        # examples below.
+        #
+        # Servers handling the these requests must answer the `/requestToken` endpoints defined
+        # by the Matrix Identity Service API specification:
+        # https://matrix.org/docs/spec/identity_service/latest
+        #
+        account_threepid_delegates:
+            #email: https://example.com     # Delegate email sending to matrix.org
+            #msisdn: http://localhost:8090  # Delegate SMS sending to this local process
+
         # Users who register on this homeserver will automatically be joined
         # to these rooms
         #
diff --git a/synapse/config/server.py b/synapse/config/server.py
index 2abdef0971..c8b9fe2d0f 100644
--- a/synapse/config/server.py
+++ b/synapse/config/server.py
@@ -162,6 +162,16 @@ class ServerConfig(Config):
 
         self.mau_trial_days = config.get("mau_trial_days", 0)
 
+        # How long to keep redacted events in the database in unredacted form
+        # before redacting them.
+        redaction_retention_period = config.get("redaction_retention_period", "7d")
+        if redaction_retention_period is not None:
+            self.redaction_retention_period = self.parse_duration(
+                redaction_retention_period
+            )
+        else:
+            self.redaction_retention_period = None
+
         # Options to disable HS
         self.hs_disabled = config.get("hs_disabled", False)
         self.hs_disabled_message = config.get("hs_disabled_message", "")
@@ -718,6 +728,13 @@ class ServerConfig(Config):
         # Defaults to 'true'.
         #
         #allow_per_room_profiles: false
+
+        # How long to keep redacted events in unredacted form in the database. After
+        # this period redacted events get replaced with their redacted form in the DB.
+        #
+        # Defaults to `7d`. Set to `null` to disable.
+        #
+        redaction_retention_period: 7d
         """
             % locals()
         )
diff --git a/synapse/config/stats.py b/synapse/config/stats.py
index b518a3ed9c..b18ddbd1fa 100644
--- a/synapse/config/stats.py
+++ b/synapse/config/stats.py
@@ -27,19 +27,16 @@ class StatsConfig(Config):
 
     def read_config(self, config, **kwargs):
         self.stats_enabled = True
-        self.stats_bucket_size = 86400
+        self.stats_bucket_size = 86400 * 1000
         self.stats_retention = sys.maxsize
         stats_config = config.get("stats", None)
         if stats_config:
             self.stats_enabled = stats_config.get("enabled", self.stats_enabled)
-            self.stats_bucket_size = (
-                self.parse_duration(stats_config.get("bucket_size", "1d")) / 1000
+            self.stats_bucket_size = self.parse_duration(
+                stats_config.get("bucket_size", "1d")
             )
-            self.stats_retention = (
-                self.parse_duration(
-                    stats_config.get("retention", "%ds" % (sys.maxsize,))
-                )
-                / 1000
+            self.stats_retention = self.parse_duration(
+                stats_config.get("retention", "%ds" % (sys.maxsize,))
             )
 
     def generate_config_section(self, config_dir_path, server_name, **kwargs):
diff --git a/synapse/event_auth.py b/synapse/event_auth.py
index cd52e3f867..4e91df60e6 100644
--- a/synapse/event_auth.py
+++ b/synapse/event_auth.py
@@ -637,11 +637,11 @@ def auth_types_for_event(event):
     if event.type == EventTypes.Create:
         return []
 
-    auth_types = []
-
-    auth_types.append((EventTypes.PowerLevels, ""))
-    auth_types.append((EventTypes.Member, event.sender))
-    auth_types.append((EventTypes.Create, ""))
+    auth_types = [
+        (EventTypes.PowerLevels, ""),
+        (EventTypes.Member, event.sender),
+        (EventTypes.Create, ""),
+    ]
 
     if event.type == EventTypes.Member:
         membership = event.content["membership"]
diff --git a/synapse/federation/federation_server.py b/synapse/federation/federation_server.py
index e5f0b90aec..da06ab379d 100644
--- a/synapse/federation/federation_server.py
+++ b/synapse/federation/federation_server.py
@@ -669,9 +669,9 @@ class FederationServer(FederationBase):
         return ret
 
     @defer.inlineCallbacks
-    def on_exchange_third_party_invite_request(self, origin, room_id, event_dict):
+    def on_exchange_third_party_invite_request(self, room_id, event_dict):
         ret = yield self.handler.on_exchange_third_party_invite_request(
-            origin, room_id, event_dict
+            room_id, event_dict
         )
         return ret
 
diff --git a/synapse/federation/sender/transaction_manager.py b/synapse/federation/sender/transaction_manager.py
index 62ca6a3e87..5b6c79c51a 100644
--- a/synapse/federation/sender/transaction_manager.py
+++ b/synapse/federation/sender/transaction_manager.py
@@ -26,6 +26,7 @@ from synapse.logging.opentracing import (
     set_tag,
     start_active_span_follows_from,
     tags,
+    whitelisted_homeserver,
 )
 from synapse.util.metrics import measure_func
 
@@ -59,9 +60,15 @@ class TransactionManager(object):
         # The span_contexts is a generator so that it won't be evaluated if
         # opentracing is disabled. (Yay speed!)
 
-        span_contexts = (
-            extract_text_map(json.loads(edu.get_context())) for edu in pending_edus
-        )
+        span_contexts = []
+        keep_destination = whitelisted_homeserver(destination)
+
+        for edu in pending_edus:
+            context = edu.get_context()
+            if context:
+                span_contexts.append(extract_text_map(json.loads(context)))
+            if keep_destination:
+                edu.strip_context()
 
         with start_active_span_follows_from("send_transaction", span_contexts):
 
diff --git a/synapse/federation/transport/server.py b/synapse/federation/transport/server.py
index f9930b6460..7dc696c7ae 100644
--- a/synapse/federation/transport/server.py
+++ b/synapse/federation/transport/server.py
@@ -342,7 +342,11 @@ class BaseFederationServlet(object):
                 continue
 
             server.register_paths(
-                method, (pattern,), self._wrap(code), self.__class__.__name__
+                method,
+                (pattern,),
+                self._wrap(code),
+                self.__class__.__name__,
+                trace=False,
             )
 
 
@@ -571,7 +575,7 @@ class FederationThirdPartyInviteExchangeServlet(BaseFederationServlet):
 
     async def on_PUT(self, origin, content, query, room_id):
         content = await self.handler.on_exchange_third_party_invite_request(
-            origin, room_id, content
+            room_id, content
         )
         return 200, content
 
diff --git a/synapse/federation/units.py b/synapse/federation/units.py
index aa84621206..b4d743cde7 100644
--- a/synapse/federation/units.py
+++ b/synapse/federation/units.py
@@ -41,6 +41,9 @@ class Edu(JsonEncodedObject):
     def get_context(self):
         return getattr(self, "content", {}).get("org.matrix.opentracing_context", "{}")
 
+    def strip_context(self):
+        getattr(self, "content", {})["org.matrix.opentracing_context"] = "{}"
+
 
 class Transaction(JsonEncodedObject):
     """ A transaction is a list of Pdus and Edus to be sent to a remote home
diff --git a/synapse/handlers/account_validity.py b/synapse/handlers/account_validity.py
index 34574f1a12..d04e0fe576 100644
--- a/synapse/handlers/account_validity.py
+++ b/synapse/handlers/account_validity.py
@@ -38,6 +38,7 @@ logger = logging.getLogger(__name__)
 class AccountValidityHandler(object):
     def __init__(self, hs):
         self.hs = hs
+        self.config = hs.config
         self.store = self.hs.get_datastore()
         self.sendmail = self.hs.get_sendmail()
         self.clock = self.hs.get_clock()
@@ -62,9 +63,14 @@ class AccountValidityHandler(object):
             self._raw_from = email.utils.parseaddr(self._from_string)[1]
 
             self._template_html, self._template_text = load_jinja2_templates(
-                config=self.hs.config,
-                template_html_name=self.hs.config.email_expiry_template_html,
-                template_text_name=self.hs.config.email_expiry_template_text,
+                self.config.email_template_dir,
+                [
+                    self.config.email_expiry_template_html,
+                    self.config.email_expiry_template_text,
+                ],
+                apply_format_ts_filter=True,
+                apply_mxc_to_http_filter=True,
+                public_baseurl=self.config.public_baseurl,
             )
 
             # Check the renewal emails to send and send them every 30min.
diff --git a/synapse/handlers/auth.py b/synapse/handlers/auth.py
index f844409d21..374372b69e 100644
--- a/synapse/handlers/auth.py
+++ b/synapse/handlers/auth.py
@@ -38,6 +38,7 @@ from synapse.api.errors import (
     UserDeactivatedError,
 )
 from synapse.api.ratelimiting import Ratelimiter
+from synapse.config.emailconfig import ThreepidBehaviour
 from synapse.logging.context import defer_to_thread
 from synapse.module_api import ModuleApi
 from synapse.types import UserID
@@ -158,7 +159,7 @@ class AuthHandler(BaseHandler):
         return params
 
     @defer.inlineCallbacks
-    def check_auth(self, flows, clientdict, clientip, password_servlet=False):
+    def check_auth(self, flows, clientdict, clientip):
         """
         Takes a dictionary sent by the client in the login / registration
         protocol and handles the User-Interactive Auth flow.
@@ -182,16 +183,6 @@ class AuthHandler(BaseHandler):
 
             clientip (str): The IP address of the client.
 
-            password_servlet (bool): Whether the request originated from
-                PasswordRestServlet.
-                XXX: This is a temporary hack to distinguish between checking
-                for threepid validations locally (in the case of password
-                resets) and using the identity server (in the case of binding
-                a 3PID during registration). Once we start using the
-                homeserver for both tasks, this distinction will no longer be
-                necessary.
-
-
         Returns:
             defer.Deferred[dict, dict, str]: a deferred tuple of
                 (creds, params, session_id).
@@ -247,9 +238,7 @@ class AuthHandler(BaseHandler):
         if "type" in authdict:
             login_type = authdict["type"]
             try:
-                result = yield self._check_auth_dict(
-                    authdict, clientip, password_servlet=password_servlet
-                )
+                result = yield self._check_auth_dict(authdict, clientip)
                 if result:
                     creds[login_type] = result
                     self._save_session(session)
@@ -356,7 +345,7 @@ class AuthHandler(BaseHandler):
         return sess.setdefault("serverdict", {}).get(key, default)
 
     @defer.inlineCallbacks
-    def _check_auth_dict(self, authdict, clientip, password_servlet=False):
+    def _check_auth_dict(self, authdict, clientip):
         """Attempt to validate the auth dict provided by a client
 
         Args:
@@ -374,11 +363,7 @@ class AuthHandler(BaseHandler):
         login_type = authdict["type"]
         checker = self.checkers.get(login_type)
         if checker is not None:
-            # XXX: Temporary workaround for having Synapse handle password resets
-            # See AuthHandler.check_auth for further details
-            res = yield checker(
-                authdict, clientip=clientip, password_servlet=password_servlet
-            )
+            res = yield checker(authdict, clientip=clientip)
             return res
 
         # build a v1-login-style dict out of the authdict and fall back to the
@@ -449,7 +434,7 @@ class AuthHandler(BaseHandler):
         return defer.succeed(True)
 
     @defer.inlineCallbacks
-    def _check_threepid(self, medium, authdict, password_servlet=False, **kwargs):
+    def _check_threepid(self, medium, authdict, **kwargs):
         if "threepid_creds" not in authdict:
             raise LoginError(400, "Missing threepid_creds", Codes.MISSING_PARAM)
 
@@ -458,12 +443,18 @@ class AuthHandler(BaseHandler):
         identity_handler = self.hs.get_handlers().identity_handler
 
         logger.info("Getting validated threepid. threepidcreds: %r", (threepid_creds,))
-        if (
-            not password_servlet
-            or self.hs.config.email_password_reset_behaviour == "remote"
-        ):
-            threepid = yield identity_handler.threepid_from_creds(threepid_creds)
-        elif self.hs.config.email_password_reset_behaviour == "local":
+        if self.hs.config.threepid_behaviour_email == ThreepidBehaviour.REMOTE:
+            if medium == "email":
+                threepid = yield identity_handler.threepid_from_creds(
+                    self.hs.config.account_threepid_delegate_email, threepid_creds
+                )
+            elif medium == "msisdn":
+                threepid = yield identity_handler.threepid_from_creds(
+                    self.hs.config.account_threepid_delegate_msisdn, threepid_creds
+                )
+            else:
+                raise SynapseError(400, "Unrecognized threepid medium: %s" % (medium,))
+        elif self.hs.config.threepid_behaviour_email == ThreepidBehaviour.LOCAL:
             row = yield self.store.get_threepid_validation_session(
                 medium,
                 threepid_creds["client_secret"],
diff --git a/synapse/handlers/devicemessage.py b/synapse/handlers/devicemessage.py
index 01731cb2d0..0043cbea17 100644
--- a/synapse/handlers/devicemessage.py
+++ b/synapse/handlers/devicemessage.py
@@ -25,7 +25,6 @@ from synapse.logging.opentracing import (
     log_kv,
     set_tag,
     start_active_span,
-    whitelisted_homeserver,
 )
 from synapse.types import UserID, get_domain_from_id
 from synapse.util.stringutils import random_string
@@ -121,9 +120,7 @@ class DeviceMessageHandler(object):
                     "sender": sender_user_id,
                     "type": message_type,
                     "message_id": message_id,
-                    "org.matrix.opentracing_context": json.dumps(context)
-                    if whitelisted_homeserver(destination)
-                    else None,
+                    "org.matrix.opentracing_context": json.dumps(context),
                 }
 
         log_kv({"local_messages": local_messages})
diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py
index 538b16efd6..f72b81d419 100644
--- a/synapse/handlers/federation.py
+++ b/synapse/handlers/federation.py
@@ -2530,12 +2530,17 @@ class FederationHandler(BaseHandler):
 
     @defer.inlineCallbacks
     @log_function
-    def on_exchange_third_party_invite_request(self, origin, room_id, event_dict):
+    def on_exchange_third_party_invite_request(self, room_id, event_dict):
         """Handle an exchange_third_party_invite request from a remote server
 
         The remote server will call this when it wants to turn a 3pid invite
         into a normal m.room.member invite.
 
+        Args:
+            room_id (str): The ID of the room.
+
+            event_dict (dict[str, Any]): Dictionary containing the event body.
+
         Returns:
             Deferred: resolves (to None)
         """
diff --git a/synapse/handlers/identity.py b/synapse/handlers/identity.py
index 97daca5fee..0e25582b26 100644
--- a/synapse/handlers/identity.py
+++ b/synapse/handlers/identity.py
@@ -29,6 +29,7 @@ from synapse.api.errors import (
     HttpResponseException,
     SynapseError,
 )
+from synapse.util.stringutils import random_string
 
 from ._base import BaseHandler
 
@@ -41,87 +42,128 @@ class IdentityHandler(BaseHandler):
 
         self.http_client = hs.get_simple_http_client()
         self.federation_http_client = hs.get_http_client()
+        self.hs = hs
 
-        self.trusted_id_servers = set(hs.config.trusted_third_party_id_servers)
-        self.trust_any_id_server_just_for_testing_do_not_use = (
-            hs.config.use_insecure_ssl_client_just_for_testing_do_not_use
-        )
+    def _extract_items_from_creds_dict(self, creds):
+        """
+        Retrieve entries from a "credentials" dictionary
 
-    def _should_trust_id_server(self, id_server):
-        if id_server not in self.trusted_id_servers:
-            if self.trust_any_id_server_just_for_testing_do_not_use:
-                logger.warn(
-                    "Trusting untrustworthy ID server %r even though it isn't"
-                    " in the trusted id list for testing because"
-                    " 'use_insecure_ssl_client_just_for_testing_do_not_use'"
-                    " is set in the config",
-                    id_server,
-                )
-            else:
-                return False
-        return True
+        Args:
+            creds (dict[str, str]): Dictionary of credentials that contain the following keys:
+                * client_secret|clientSecret: A unique secret str provided by the client
+                * id_server|idServer: the domain of the identity server to query
+                * id_access_token: The access token to authenticate to the identity
+                    server with.
+
+        Returns:
+            tuple(str, str, str|None): A tuple containing the client_secret, the id_server,
+                and the id_access_token value if available.
+        """
+        client_secret = creds.get("client_secret") or creds.get("clientSecret")
+        if not client_secret:
+            raise SynapseError(
+                400, "No client_secret in creds", errcode=Codes.MISSING_PARAM
+            )
+
+        id_server = creds.get("id_server") or creds.get("idServer")
+        if not id_server:
+            raise SynapseError(
+                400, "No id_server in creds", errcode=Codes.MISSING_PARAM
+            )
+
+        id_access_token = creds.get("id_access_token")
+        return client_secret, id_server, id_access_token
 
     @defer.inlineCallbacks
-    def threepid_from_creds(self, creds):
-        if "id_server" in creds:
-            id_server = creds["id_server"]
-        elif "idServer" in creds:
-            id_server = creds["idServer"]
-        else:
-            raise SynapseError(400, "No id_server in creds")
+    def threepid_from_creds(self, id_server, creds):
+        """
+        Retrieve and validate a threepid identifier from a "credentials" dictionary against a
+        given identity server
 
-        if "client_secret" in creds:
-            client_secret = creds["client_secret"]
-        elif "clientSecret" in creds:
-            client_secret = creds["clientSecret"]
-        else:
-            raise SynapseError(400, "No client_secret in creds")
+        Args:
+            id_server (str|None): The identity server to validate 3PIDs against. If None,
+                we will attempt to extract id_server creds
 
-        if not self._should_trust_id_server(id_server):
-            logger.warn(
-                "%s is not a trusted ID server: rejecting 3pid " + "credentials",
-                id_server,
-            )
-            return None
+            creds (dict[str, str]): Dictionary containing the following keys:
+                * id_server|idServer: An optional domain name of an identity server
+                * client_secret|clientSecret: A unique secret str provided by the client
+                * sid: The ID of the validation session
 
-        try:
-            data = yield self.http_client.get_json(
-                "https://%s%s"
-                % (id_server, "/_matrix/identity/api/v1/3pid/getValidated3pid"),
-                {"sid": creds["sid"], "client_secret": client_secret},
+        Returns:
+            Deferred[dict[str,str|int]|None]: A dictionary consisting of response params to
+                the /getValidated3pid endpoint of the Identity Service API, or None if the
+                threepid was not found
+        """
+        client_secret = creds.get("client_secret") or creds.get("clientSecret")
+        if not client_secret:
+            raise SynapseError(
+                400, "Missing param client_secret in creds", errcode=Codes.MISSING_PARAM
             )
-        except HttpResponseException as e:
-            logger.info("getValidated3pid failed with Matrix error: %r", e)
-            raise e.to_synapse_error()
+        session_id = creds.get("sid")
+        if not session_id:
+            raise SynapseError(
+                400, "Missing param session_id in creds", errcode=Codes.MISSING_PARAM
+            )
+        if not id_server:
+            # Attempt to get the id_server from the creds dict
+            id_server = creds.get("id_server") or creds.get("idServer")
+            if not id_server:
+                raise SynapseError(
+                    400, "Missing param id_server in creds", errcode=Codes.MISSING_PARAM
+                )
 
-        if "medium" in data:
-            return data
-        return None
+        query_params = {"sid": session_id, "client_secret": client_secret}
+
+        url = "https://%s%s" % (
+            id_server,
+            "/_matrix/identity/api/v1/3pid/getValidated3pid",
+        )
+
+        data = yield self.http_client.get_json(url, query_params)
+        return data if "medium" in data else None
 
     @defer.inlineCallbacks
-    def bind_threepid(self, creds, mxid):
+    def bind_threepid(self, creds, mxid, use_v2=True):
+        """Bind a 3PID to an identity server
+
+        Args:
+            creds (dict[str, str]): Dictionary of credentials that contain the following keys:
+                * client_secret|clientSecret: A unique secret str provided by the client
+                * id_server|idServer: the domain of the identity server to query
+                * id_access_token: The access token to authenticate to the identity
+                    server with. Required if use_v2 is true
+            mxid (str): The MXID to bind the 3PID to
+            use_v2 (bool): Whether to use v2 Identity Service API endpoints
+
+        Returns:
+            Deferred[dict]: The response from the identity server
+        """
         logger.debug("binding threepid %r to %s", creds, mxid)
-        data = None
 
-        if "id_server" in creds:
-            id_server = creds["id_server"]
-        elif "idServer" in creds:
-            id_server = creds["idServer"]
-        else:
-            raise SynapseError(400, "No id_server in creds")
+        client_secret, id_server, id_access_token = self._extract_items_from_creds_dict(
+            creds
+        )
+
+        sid = creds.get("sid")
+        if not sid:
+            raise SynapseError(
+                400, "No sid in three_pid_creds", errcode=Codes.MISSING_PARAM
+            )
 
-        if "client_secret" in creds:
-            client_secret = creds["client_secret"]
-        elif "clientSecret" in creds:
-            client_secret = creds["clientSecret"]
+        # If an id_access_token is not supplied, force usage of v1
+        if id_access_token is None:
+            use_v2 = False
+
+        # Decide which API endpoint URLs to use
+        bind_data = {"sid": sid, "client_secret": client_secret, "mxid": mxid}
+        if use_v2:
+            bind_url = "https://%s/_matrix/identity/v2/3pid/bind" % (id_server,)
+            bind_data["id_access_token"] = id_access_token
         else:
-            raise SynapseError(400, "No client_secret in creds")
+            bind_url = "https://%s/_matrix/identity/api/v1/3pid/bind" % (id_server,)
 
         try:
-            data = yield self.http_client.post_json_get_json(
-                "https://%s%s" % (id_server, "/_matrix/identity/api/v1/3pid/bind"),
-                {"sid": creds["sid"], "client_secret": client_secret, "mxid": mxid},
-            )
+            data = yield self.http_client.post_json_get_json(bind_url, bind_data)
             logger.debug("bound threepid %r to %s", creds, mxid)
 
             # Remember where we bound the threepid
@@ -131,13 +173,23 @@ class IdentityHandler(BaseHandler):
                 address=data["address"],
                 id_server=id_server,
             )
+
+            return data
+        except HttpResponseException as e:
+            if e.code != 404 or not use_v2:
+                logger.error("3PID bind failed with Matrix error: %r", e)
+                raise e.to_synapse_error()
         except CodeMessageException as e:
             data = json.loads(e.msg)  # XXX WAT?
-        return data
+            return data
+
+        logger.info("Got 404 when POSTing JSON %s, falling back to v1 URL", bind_url)
+        return (yield self.bind_threepid(creds, mxid, use_v2=False))
 
     @defer.inlineCallbacks
     def try_unbind_threepid(self, mxid, threepid):
-        """Removes a binding from an identity server
+        """Attempt to remove a 3PID from an identity server, or if one is not provided, all
+        identity servers we're aware the binding is present on
 
         Args:
             mxid (str): Matrix user ID of binding to be removed
@@ -188,6 +240,8 @@ class IdentityHandler(BaseHandler):
             server doesn't support unbinding
         """
         url = "https://%s/_matrix/identity/api/v1/3pid/unbind" % (id_server,)
+        url_bytes = "/_matrix/identity/api/v1/3pid/unbind".encode("ascii")
+
         content = {
             "mxid": mxid,
             "threepid": {"medium": threepid["medium"], "address": threepid["address"]},
@@ -199,7 +253,7 @@ class IdentityHandler(BaseHandler):
         auth_headers = self.federation_http_client.build_auth_headers(
             destination=None,
             method="POST",
-            url_bytes="/_matrix/identity/api/v1/3pid/unbind".encode("ascii"),
+            url_bytes=url_bytes,
             content=content,
             destination_is=id_server,
         )
@@ -227,27 +281,121 @@ class IdentityHandler(BaseHandler):
         return changed
 
     @defer.inlineCallbacks
+    def send_threepid_validation(
+        self,
+        email_address,
+        client_secret,
+        send_attempt,
+        send_email_func,
+        next_link=None,
+    ):
+        """Send a threepid validation email for password reset or
+        registration purposes
+
+        Args:
+            email_address (str): The user's email address
+            client_secret (str): The provided client secret
+            send_attempt (int): Which send attempt this is
+            send_email_func (func): A function that takes an email address, token,
+                                    client_secret and session_id, sends an email
+                                    and returns a Deferred.
+            next_link (str|None): The URL to redirect the user to after validation
+
+        Returns:
+            The new session_id upon success
+
+        Raises:
+            SynapseError is an error occurred when sending the email
+        """
+        # Check that this email/client_secret/send_attempt combo is new or
+        # greater than what we've seen previously
+        session = yield self.store.get_threepid_validation_session(
+            "email", client_secret, address=email_address, validated=False
+        )
+
+        # Check to see if a session already exists and that it is not yet
+        # marked as validated
+        if session and session.get("validated_at") is None:
+            session_id = session["session_id"]
+            last_send_attempt = session["last_send_attempt"]
+
+            # Check that the send_attempt is higher than previous attempts
+            if send_attempt <= last_send_attempt:
+                # If not, just return a success without sending an email
+                return session_id
+        else:
+            # An non-validated session does not exist yet.
+            # Generate a session id
+            session_id = random_string(16)
+
+        # Generate a new validation token
+        token = random_string(32)
+
+        # Send the mail with the link containing the token, client_secret
+        # and session_id
+        try:
+            yield send_email_func(email_address, token, client_secret, session_id)
+        except Exception:
+            logger.exception(
+                "Error sending threepid validation email to %s", email_address
+            )
+            raise SynapseError(500, "An error was encountered when sending the email")
+
+        token_expires = (
+            self.hs.clock.time_msec() + self.hs.config.email_validation_token_lifetime
+        )
+
+        yield self.store.start_or_continue_validation_session(
+            "email",
+            email_address,
+            session_id,
+            client_secret,
+            send_attempt,
+            next_link,
+            token,
+            token_expires,
+        )
+
+        return session_id
+
+    @defer.inlineCallbacks
     def requestEmailToken(
         self, id_server, email, client_secret, send_attempt, next_link=None
     ):
-        if not self._should_trust_id_server(id_server):
-            raise SynapseError(
-                400, "Untrusted ID server '%s'" % id_server, Codes.SERVER_NOT_TRUSTED
-            )
+        """
+        Request an external server send an email on our behalf for the purposes of threepid
+        validation.
 
+        Args:
+            id_server (str): The identity server to proxy to
+            email (str): The email to send the message to
+            client_secret (str): The unique client_secret sends by the user
+            send_attempt (int): Which attempt this is
+            next_link: A link to redirect the user to once they submit the token
+
+        Returns:
+            The json response body from the server
+        """
         params = {
             "email": email,
             "client_secret": client_secret,
             "send_attempt": send_attempt,
         }
-
         if next_link:
-            params.update({"next_link": next_link})
+            params["next_link"] = next_link
+
+        if self.hs.config.using_identity_server_from_trusted_list:
+            # Warn that a deprecated config option is in use
+            logger.warn(
+                '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 "
+                "details and update your config file."
+            )
 
         try:
             data = yield self.http_client.post_json_get_json(
-                "https://%s%s"
-                % (id_server, "/_matrix/identity/api/v1/validate/email/requestToken"),
+                id_server + "/_matrix/identity/api/v1/validate/email/requestToken",
                 params,
             )
             return data
@@ -257,25 +405,49 @@ class IdentityHandler(BaseHandler):
 
     @defer.inlineCallbacks
     def requestMsisdnToken(
-        self, id_server, country, phone_number, client_secret, send_attempt, **kwargs
+        self,
+        id_server,
+        country,
+        phone_number,
+        client_secret,
+        send_attempt,
+        next_link=None,
     ):
-        if not self._should_trust_id_server(id_server):
-            raise SynapseError(
-                400, "Untrusted ID server '%s'" % id_server, Codes.SERVER_NOT_TRUSTED
-            )
+        """
+        Request an external server send an SMS message on our behalf for the purposes of
+        threepid validation.
+        Args:
+            id_server (str): The identity server to proxy to
+            country (str): The country code of the phone number
+            phone_number (str): The number to send the message to
+            client_secret (str): The unique client_secret sends by the user
+            send_attempt (int): Which attempt this is
+            next_link: A link to redirect the user to once they submit the token
 
+        Returns:
+            The json response body from the server
+        """
         params = {
             "country": country,
             "phone_number": phone_number,
             "client_secret": client_secret,
             "send_attempt": send_attempt,
         }
-        params.update(kwargs)
+        if next_link:
+            params["next_link"] = next_link
+
+        if self.hs.config.using_identity_server_from_trusted_list:
+            # Warn that a deprecated config option is in use
+            logger.warn(
+                '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 "
+                "details and update your config file."
+            )
 
         try:
             data = yield self.http_client.post_json_get_json(
-                "https://%s%s"
-                % (id_server, "/_matrix/identity/api/v1/validate/msisdn/requestToken"),
+                id_server + "/_matrix/identity/api/v1/validate/msisdn/requestToken",
                 params,
             )
             return data
diff --git a/synapse/handlers/register.py b/synapse/handlers/register.py
index e59b2a3684..06bd03b77c 100644
--- a/synapse/handlers/register.py
+++ b/synapse/handlers/register.py
@@ -275,16 +275,12 @@ class RegistrationHandler(BaseHandler):
         fake_requester = create_requester(user_id)
 
         # try to create the room if we're the first real user on the server. Note
-        # that an auto-generated support user is not a real user and will never be
+        # that an auto-generated support or bot user is not a real user and will never be
         # the user to create the room
         should_auto_create_rooms = False
-        is_support = yield self.store.is_support_user(user_id)
-        # There is an edge case where the first user is the support user, then
-        # the room is never created, though this seems unlikely and
-        # recoverable from given the support user being involved in the first
-        # place.
-        if self.hs.config.autocreate_auto_join_rooms and not is_support:
-            count = yield self.store.count_all_users()
+        is_real_user = yield self.store.is_real_user(user_id)
+        if self.hs.config.autocreate_auto_join_rooms and is_real_user:
+            count = yield self.store.count_real_users()
             should_auto_create_rooms = count == 1
         for r in self.hs.config.auto_join_rooms:
             logger.info("Auto-joining %s to %s", user_id, r)
@@ -543,9 +539,7 @@ class RegistrationHandler(BaseHandler):
         return (device_id, access_token)
 
     @defer.inlineCallbacks
-    def post_registration_actions(
-        self, user_id, auth_result, access_token, bind_email, bind_msisdn
-    ):
+    def post_registration_actions(self, user_id, auth_result, access_token):
         """A user has completed registration
 
         Args:
@@ -554,18 +548,10 @@ class RegistrationHandler(BaseHandler):
                 registered user.
             access_token (str|None): The access token of the newly logged in
                 device, or None if `inhibit_login` enabled.
-            bind_email (bool): Whether to bind the email with the identity
-                server.
-            bind_msisdn (bool): Whether to bind the msisdn with the identity
-                server.
         """
         if self.hs.config.worker_app:
             yield self._post_registration_client(
-                user_id=user_id,
-                auth_result=auth_result,
-                access_token=access_token,
-                bind_email=bind_email,
-                bind_msisdn=bind_msisdn,
+                user_id=user_id, auth_result=auth_result, access_token=access_token
             )
             return
 
@@ -578,13 +564,11 @@ class RegistrationHandler(BaseHandler):
             ):
                 yield self.store.upsert_monthly_active_user(user_id)
 
-            yield self._register_email_threepid(
-                user_id, threepid, access_token, bind_email
-            )
+            yield self._register_email_threepid(user_id, threepid, access_token)
 
         if auth_result and LoginType.MSISDN in auth_result:
             threepid = auth_result[LoginType.MSISDN]
-            yield self._register_msisdn_threepid(user_id, threepid, bind_msisdn)
+            yield self._register_msisdn_threepid(user_id, threepid)
 
         if auth_result and LoginType.TERMS in auth_result:
             yield self._on_user_consented(user_id, self.hs.config.user_consent_version)
@@ -603,14 +587,12 @@ class RegistrationHandler(BaseHandler):
         yield self.post_consent_actions(user_id)
 
     @defer.inlineCallbacks
-    def _register_email_threepid(self, user_id, threepid, token, bind_email):
+    def _register_email_threepid(self, user_id, threepid, token):
         """Add an email address as a 3pid identifier
 
         Also adds an email pusher for the email address, if configured in the
         HS config
 
-        Also optionally binds emails to the given user_id on the identity server
-
         Must be called on master.
 
         Args:
@@ -618,8 +600,6 @@ class RegistrationHandler(BaseHandler):
             threepid (object): m.login.email.identity auth response
             token (str|None): access_token for the user, or None if not logged
                 in.
-            bind_email (bool): true if the client requested the email to be
-                bound at the identity server
         Returns:
             defer.Deferred:
         """
@@ -661,28 +641,15 @@ class RegistrationHandler(BaseHandler):
                 data={},
             )
 
-        if bind_email:
-            logger.info("bind_email specified: binding")
-            logger.debug("Binding emails %s to %s" % (threepid, user_id))
-            yield self.identity_handler.bind_threepid(
-                threepid["threepid_creds"], user_id
-            )
-        else:
-            logger.info("bind_email not specified: not binding email")
-
     @defer.inlineCallbacks
-    def _register_msisdn_threepid(self, user_id, threepid, bind_msisdn):
+    def _register_msisdn_threepid(self, user_id, threepid):
         """Add a phone number as a 3pid identifier
 
-        Also optionally binds msisdn to the given user_id on the identity server
-
         Must be called on master.
 
         Args:
             user_id (str): id of user
             threepid (object): m.login.msisdn auth response
-            bind_msisdn (bool): true if the client requested the msisdn to be
-                bound at the identity server
         Returns:
             defer.Deferred:
         """
@@ -698,12 +665,3 @@ class RegistrationHandler(BaseHandler):
         yield self._auth_handler.add_threepid(
             user_id, threepid["medium"], threepid["address"], threepid["validated_at"]
         )
-
-        if bind_msisdn:
-            logger.info("bind_msisdn specified: binding")
-            logger.debug("Binding msisdn %s to %s", threepid, user_id)
-            yield self.identity_handler.bind_threepid(
-                threepid["threepid_creds"], user_id
-            )
-        else:
-            logger.info("bind_msisdn not specified: not binding msisdn")
diff --git a/synapse/handlers/stats.py b/synapse/handlers/stats.py
index 4449da6669..3c265f3718 100644
--- a/synapse/handlers/stats.py
+++ b/synapse/handlers/stats.py
@@ -14,15 +14,14 @@
 # limitations under the License.
 
 import logging
+from collections import Counter
 
 from twisted.internet import defer
 
-from synapse.api.constants import EventTypes, JoinRules, Membership
+from synapse.api.constants import EventTypes, Membership
 from synapse.handlers.state_deltas import StateDeltasHandler
 from synapse.metrics import event_processing_positions
 from synapse.metrics.background_process_metrics import run_as_background_process
-from synapse.types import UserID
-from synapse.util.metrics import Measure
 
 logger = logging.getLogger(__name__)
 
@@ -62,11 +61,10 @@ class StatsHandler(StateDeltasHandler):
     def notify_new_event(self):
         """Called when there may be more deltas to process
         """
-        if not self.hs.config.stats_enabled:
+        if not self.hs.config.stats_enabled or self._is_processing:
             return
 
-        if self._is_processing:
-            return
+        self._is_processing = True
 
         @defer.inlineCallbacks
         def process():
@@ -75,39 +73,72 @@ class StatsHandler(StateDeltasHandler):
             finally:
                 self._is_processing = False
 
-        self._is_processing = True
         run_as_background_process("stats.notify_new_event", process)
 
     @defer.inlineCallbacks
     def _unsafe_process(self):
         # If self.pos is None then means we haven't fetched it from DB
         if self.pos is None:
-            self.pos = yield self.store.get_stats_stream_pos()
-
-        # If still None then the initial background update hasn't happened yet
-        if self.pos is None:
-            return None
+            self.pos = yield self.store.get_stats_positions()
 
         # Loop round handling deltas until we're up to date
+
         while True:
-            with Measure(self.clock, "stats_delta"):
-                deltas = yield self.store.get_current_state_deltas(self.pos)
-                if not deltas:
-                    return
+            deltas = yield self.store.get_current_state_deltas(self.pos)
+
+            if deltas:
+                logger.debug("Handling %d state deltas", len(deltas))
+                room_deltas, user_deltas = yield self._handle_deltas(deltas)
+
+                max_pos = deltas[-1]["stream_id"]
+            else:
+                room_deltas = {}
+                user_deltas = {}
+                max_pos = yield self.store.get_room_max_stream_ordering()
 
-                logger.info("Handling %d state deltas", len(deltas))
-                yield self._handle_deltas(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(
+                self.pos, max_pos
+            )
+
+            for room_id, fields in room_count.items():
+                room_deltas.setdefault(room_id, {}).update(fields)
+
+            for user_id, fields in user_count.items():
+                user_deltas.setdefault(user_id, {}).update(fields)
+
+            logger.debug("room_deltas: %s", room_deltas)
+            logger.debug("user_deltas: %s", user_deltas)
 
-                self.pos = deltas[-1]["stream_id"]
-                yield self.store.update_stats_stream_pos(self.pos)
+            # Always call this so that we update the stats position.
+            yield self.store.bulk_update_stats_delta(
+                self.clock.time_msec(),
+                updates={"room": room_deltas, "user": user_deltas},
+                stream_id=max_pos,
+            )
+
+            event_processing_positions.labels("stats").set(max_pos)
 
-                event_processing_positions.labels("stats").set(self.pos)
+            if self.pos == max_pos:
+                break
+
+            self.pos = max_pos
 
     @defer.inlineCallbacks
     def _handle_deltas(self, deltas):
+        """Called with the state deltas to process
+
+        Returns:
+            Deferred[tuple[dict[str, Counter], dict[str, counter]]]
+            Resovles to two dicts, the room deltas and the user deltas,
+            mapping from room/user ID to changes in the various fields.
         """
-        Called with the state deltas to process
-        """
+
+        room_to_stats_deltas = {}
+        user_to_stats_deltas = {}
+
+        room_to_state_updates = {}
+
         for delta in deltas:
             typ = delta["type"]
             state_key = delta["state_key"]
@@ -115,11 +146,10 @@ class StatsHandler(StateDeltasHandler):
             event_id = delta["event_id"]
             stream_id = delta["stream_id"]
             prev_event_id = delta["prev_event_id"]
-            stream_pos = delta["stream_id"]
 
-            logger.debug("Handling: %r %r, %s", typ, state_key, event_id)
+            logger.debug("Handling: %r, %r %r, %s", room_id, typ, state_key, event_id)
 
-            token = yield self.store.get_earliest_token_for_room_stats(room_id)
+            token = yield self.store.get_earliest_token_for_stats("room", room_id)
 
             # If the earliest token to begin from is larger than our current
             # stream ID, skip processing this delta.
@@ -131,203 +161,132 @@ class StatsHandler(StateDeltasHandler):
                 continue
 
             if event_id is None and prev_event_id is None:
-                # Errr...
+                logger.error(
+                    "event ID is None and so is the previous event ID. stream_id: %s",
+                    stream_id,
+                )
                 continue
 
             event_content = {}
 
+            sender = None
             if event_id is not None:
                 event = yield self.store.get_event(event_id, allow_none=True)
                 if event:
                     event_content = event.content or {}
+                    sender = event.sender
+
+            # All the values in this dict are deltas (RELATIVE changes)
+            room_stats_delta = room_to_stats_deltas.setdefault(room_id, Counter())
 
-            # We use stream_pos here rather than fetch by event_id as event_id
-            # may be None
-            now = yield self.store.get_received_ts_by_stream_pos(stream_pos)
+            room_state = room_to_state_updates.setdefault(room_id, {})
 
-            # quantise time to the nearest bucket
-            now = (now // 1000 // self.stats_bucket_size) * self.stats_bucket_size
+            if prev_event_id is None:
+                # this state event doesn't overwrite another,
+                # so it is a new effective/current state event
+                room_stats_delta["current_state_events"] += 1
 
             if typ == EventTypes.Member:
                 # we could use _get_key_change here but it's a bit inefficient
                 # given we're not testing for a specific result; might as well
                 # just grab the prev_membership and membership strings and
                 # compare them.
-                prev_event_content = {}
+                # We take None rather than leave as a previous membership
+                # in the absence of a previous event because we do not want to
+                # reduce the leave count when a new-to-the-room user joins.
+                prev_membership = None
                 if prev_event_id is not None:
                     prev_event = yield self.store.get_event(
                         prev_event_id, allow_none=True
                     )
                     if prev_event:
                         prev_event_content = prev_event.content
+                        prev_membership = prev_event_content.get(
+                            "membership", Membership.LEAVE
+                        )
 
                 membership = event_content.get("membership", Membership.LEAVE)
-                prev_membership = prev_event_content.get("membership", Membership.LEAVE)
-
-                if prev_membership == membership:
-                    continue
 
-                if prev_membership == Membership.JOIN:
-                    yield self.store.update_stats_delta(
-                        now, "room", room_id, "joined_members", -1
-                    )
+                if prev_membership is None:
+                    logger.debug("No previous membership for this user.")
+                elif membership == prev_membership:
+                    pass  # noop
+                elif prev_membership == Membership.JOIN:
+                    room_stats_delta["joined_members"] -= 1
                 elif prev_membership == Membership.INVITE:
-                    yield self.store.update_stats_delta(
-                        now, "room", room_id, "invited_members", -1
-                    )
+                    room_stats_delta["invited_members"] -= 1
                 elif prev_membership == Membership.LEAVE:
-                    yield self.store.update_stats_delta(
-                        now, "room", room_id, "left_members", -1
-                    )
+                    room_stats_delta["left_members"] -= 1
                 elif prev_membership == Membership.BAN:
-                    yield self.store.update_stats_delta(
-                        now, "room", room_id, "banned_members", -1
-                    )
+                    room_stats_delta["banned_members"] -= 1
                 else:
-                    err = "%s is not a valid prev_membership" % (repr(prev_membership),)
-                    logger.error(err)
-                    raise ValueError(err)
+                    raise ValueError(
+                        "%r is not a valid prev_membership" % (prev_membership,)
+                    )
 
+                if membership == prev_membership:
+                    pass  # noop
                 if membership == Membership.JOIN:
-                    yield self.store.update_stats_delta(
-                        now, "room", room_id, "joined_members", +1
-                    )
+                    room_stats_delta["joined_members"] += 1
                 elif membership == Membership.INVITE:
-                    yield self.store.update_stats_delta(
-                        now, "room", room_id, "invited_members", +1
-                    )
+                    room_stats_delta["invited_members"] += 1
+
+                    if sender and self.is_mine_id(sender):
+                        user_to_stats_deltas.setdefault(sender, Counter())[
+                            "invites_sent"
+                        ] += 1
+
                 elif membership == Membership.LEAVE:
-                    yield self.store.update_stats_delta(
-                        now, "room", room_id, "left_members", +1
-                    )
+                    room_stats_delta["left_members"] += 1
                 elif membership == Membership.BAN:
-                    yield self.store.update_stats_delta(
-                        now, "room", room_id, "banned_members", +1
-                    )
+                    room_stats_delta["banned_members"] += 1
                 else:
-                    err = "%s is not a valid membership" % (repr(membership),)
-                    logger.error(err)
-                    raise ValueError(err)
+                    raise ValueError("%r is not a valid membership" % (membership,))
 
                 user_id = state_key
                 if self.is_mine_id(user_id):
-                    # update user_stats as it's one of our users
-                    public = yield self._is_public_room(room_id)
-
-                    if membership == Membership.LEAVE:
-                        yield self.store.update_stats_delta(
-                            now,
-                            "user",
-                            user_id,
-                            "public_rooms" if public else "private_rooms",
-                            -1,
-                        )
-                    elif membership == Membership.JOIN:
-                        yield self.store.update_stats_delta(
-                            now,
-                            "user",
-                            user_id,
-                            "public_rooms" if public else "private_rooms",
-                            +1,
-                        )
+                    # this accounts for transitions like leave ā†’ ban and so on.
+                    has_changed_joinedness = (prev_membership == Membership.JOIN) != (
+                        membership == Membership.JOIN
+                    )
 
-            elif typ == EventTypes.Create:
-                # Newly created room. Add it with all blank portions.
-                yield self.store.update_room_state(
-                    room_id,
-                    {
-                        "join_rules": None,
-                        "history_visibility": None,
-                        "encryption": None,
-                        "name": None,
-                        "topic": None,
-                        "avatar": None,
-                        "canonical_alias": None,
-                    },
-                )
+                    if has_changed_joinedness:
+                        delta = +1 if membership == Membership.JOIN else -1
 
-            elif typ == EventTypes.JoinRules:
-                yield self.store.update_room_state(
-                    room_id, {"join_rules": event_content.get("join_rule")}
-                )
+                        user_to_stats_deltas.setdefault(user_id, Counter())[
+                            "joined_rooms"
+                        ] += delta
 
-                is_public = yield self._get_key_change(
-                    prev_event_id, event_id, "join_rule", JoinRules.PUBLIC
-                )
-                if is_public is not None:
-                    yield self.update_public_room_stats(now, room_id, is_public)
+                        room_stats_delta["local_users_in_room"] += delta
 
-            elif typ == EventTypes.RoomHistoryVisibility:
-                yield self.store.update_room_state(
-                    room_id,
-                    {"history_visibility": event_content.get("history_visibility")},
+            elif typ == EventTypes.Create:
+                room_state["is_federatable"] = (
+                    event_content.get("m.federate", True) is True
                 )
-
-                is_public = yield self._get_key_change(
-                    prev_event_id, event_id, "history_visibility", "world_readable"
+                if sender and self.is_mine_id(sender):
+                    user_to_stats_deltas.setdefault(sender, Counter())[
+                        "rooms_created"
+                    ] += 1
+            elif typ == EventTypes.JoinRules:
+                room_state["join_rules"] = event_content.get("join_rule")
+            elif typ == EventTypes.RoomHistoryVisibility:
+                room_state["history_visibility"] = event_content.get(
+                    "history_visibility"
                 )
-                if is_public is not None:
-                    yield self.update_public_room_stats(now, room_id, is_public)
-
             elif typ == EventTypes.Encryption:
-                yield self.store.update_room_state(
-                    room_id, {"encryption": event_content.get("algorithm")}
-                )
+                room_state["encryption"] = event_content.get("algorithm")
             elif typ == EventTypes.Name:
-                yield self.store.update_room_state(
-                    room_id, {"name": event_content.get("name")}
-                )
+                room_state["name"] = event_content.get("name")
             elif typ == EventTypes.Topic:
-                yield self.store.update_room_state(
-                    room_id, {"topic": event_content.get("topic")}
-                )
+                room_state["topic"] = event_content.get("topic")
             elif typ == EventTypes.RoomAvatar:
-                yield self.store.update_room_state(
-                    room_id, {"avatar": event_content.get("url")}
-                )
+                room_state["avatar"] = event_content.get("url")
             elif typ == EventTypes.CanonicalAlias:
-                yield self.store.update_room_state(
-                    room_id, {"canonical_alias": event_content.get("alias")}
-                )
+                room_state["canonical_alias"] = event_content.get("alias")
+            elif typ == EventTypes.GuestAccess:
+                room_state["guest_access"] = event_content.get("guest_access")
 
-    @defer.inlineCallbacks
-    def update_public_room_stats(self, ts, room_id, is_public):
-        """
-        Increment/decrement a user's number of public rooms when a room they are
-        in changes to/from public visibility.
+        for room_id, state in room_to_state_updates.items():
+            yield self.store.update_room_state(room_id, state)
 
-        Args:
-            ts (int): Timestamp in seconds
-            room_id (str)
-            is_public (bool)
-        """
-        # For now, blindly iterate over all local users in the room so that
-        # we can handle the whole problem of copying buckets over as needed
-        user_ids = yield self.store.get_users_in_room(room_id)
-
-        for user_id in user_ids:
-            if self.hs.is_mine(UserID.from_string(user_id)):
-                yield self.store.update_stats_delta(
-                    ts, "user", user_id, "public_rooms", +1 if is_public else -1
-                )
-                yield self.store.update_stats_delta(
-                    ts, "user", user_id, "private_rooms", -1 if is_public else +1
-                )
-
-    @defer.inlineCallbacks
-    def _is_public_room(self, room_id):
-        join_rules = yield self.state.get_current_state(room_id, EventTypes.JoinRules)
-        history_visibility = yield self.state.get_current_state(
-            room_id, EventTypes.RoomHistoryVisibility
-        )
-
-        if (join_rules and join_rules.content.get("join_rule") == JoinRules.PUBLIC) or (
-            (
-                history_visibility
-                and history_visibility.content.get("history_visibility")
-                == "world_readable"
-            )
-        ):
-            return True
-        else:
-            return False
+        return room_to_stats_deltas, user_to_stats_deltas
diff --git a/synapse/http/client.py b/synapse/http/client.py
index 0ae6db8ea7..51765ae3c0 100644
--- a/synapse/http/client.py
+++ b/synapse/http/client.py
@@ -46,6 +46,7 @@ from synapse.http import (
     redact_uri,
 )
 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
 from synapse.util.caches import CACHE_SIZE_FACTOR
 
@@ -269,42 +270,56 @@ class SimpleHttpClient(object):
         # log request but strip `access_token` (AS requests for example include this)
         logger.info("Sending request %s %s", method, redact_uri(uri))
 
-        try:
-            body_producer = None
-            if data is not None:
-                body_producer = QuieterFileBodyProducer(BytesIO(data))
-
-            request_deferred = treq.request(
-                method,
-                uri,
-                agent=self.agent,
-                data=body_producer,
-                headers=headers,
-                **self._extra_treq_args
-            )
-            request_deferred = timeout_deferred(
-                request_deferred,
-                60,
-                self.hs.get_reactor(),
-                cancelled_to_request_timed_out_error,
-            )
-            response = yield make_deferred_yieldable(request_deferred)
-
-            incoming_responses_counter.labels(method, response.code).inc()
-            logger.info(
-                "Received response to %s %s: %s", method, redact_uri(uri), response.code
-            )
-            return response
-        except Exception as e:
-            incoming_responses_counter.labels(method, "ERR").inc()
-            logger.info(
-                "Error sending request to  %s %s: %s %s",
-                method,
-                redact_uri(uri),
-                type(e).__name__,
-                e.args[0],
-            )
-            raise
+        with start_active_span(
+            "outgoing-client-request",
+            tags={
+                tags.SPAN_KIND: tags.SPAN_KIND_RPC_CLIENT,
+                tags.HTTP_METHOD: method,
+                tags.HTTP_URL: uri,
+            },
+            finish_on_close=True,
+        ):
+            try:
+                body_producer = None
+                if data is not None:
+                    body_producer = QuieterFileBodyProducer(BytesIO(data))
+
+                request_deferred = treq.request(
+                    method,
+                    uri,
+                    agent=self.agent,
+                    data=body_producer,
+                    headers=headers,
+                    **self._extra_treq_args
+                )
+                request_deferred = timeout_deferred(
+                    request_deferred,
+                    60,
+                    self.hs.get_reactor(),
+                    cancelled_to_request_timed_out_error,
+                )
+                response = yield make_deferred_yieldable(request_deferred)
+
+                incoming_responses_counter.labels(method, response.code).inc()
+                logger.info(
+                    "Received response to %s %s: %s",
+                    method,
+                    redact_uri(uri),
+                    response.code,
+                )
+                return response
+            except Exception as e:
+                incoming_responses_counter.labels(method, "ERR").inc()
+                logger.info(
+                    "Error sending request to  %s %s: %s %s",
+                    method,
+                    redact_uri(uri),
+                    type(e).__name__,
+                    e.args[0],
+                )
+                set_tag(tags.ERROR, True)
+                set_tag("error_reason", e.args[0])
+                raise
 
     @defer.inlineCallbacks
     def post_urlencoded_get_json(self, uri, args={}, headers=None):
diff --git a/synapse/http/matrixfederationclient.py b/synapse/http/matrixfederationclient.py
index 4326e98a28..3f7c93ffcb 100644
--- a/synapse/http/matrixfederationclient.py
+++ b/synapse/http/matrixfederationclient.py
@@ -345,7 +345,6 @@ class MatrixFederationHttpClient(object):
         else:
             query_bytes = b""
 
-        # Retreive current span
         scope = start_active_span(
             "outgoing-federation-request",
             tags={
diff --git a/synapse/http/server.py b/synapse/http/server.py
index e6f351ba3b..cb9158fe1b 100644
--- a/synapse/http/server.py
+++ b/synapse/http/server.py
@@ -40,6 +40,7 @@ from synapse.api.errors import (
     UnrecognizedRequestError,
 )
 from synapse.logging.context import preserve_fn
+from synapse.logging.opentracing import trace_servlet
 from synapse.util.caches import intern_dict
 
 logger = logging.getLogger(__name__)
@@ -257,7 +258,9 @@ class JsonResource(HttpServer, resource.Resource):
         self.path_regexs = {}
         self.hs = hs
 
-    def register_paths(self, method, path_patterns, callback, servlet_classname):
+    def register_paths(
+        self, method, path_patterns, callback, servlet_classname, trace=True
+    ):
         """
         Registers a request handler against a regular expression. Later request URLs are
         checked against these regular expressions in order to identify an appropriate
@@ -273,8 +276,16 @@ class JsonResource(HttpServer, resource.Resource):
 
             servlet_classname (str): The name of the handler to be used in prometheus
                 and opentracing logs.
+
+            trace (bool): Whether we should start a span to trace the servlet.
         """
         method = method.encode("utf-8")  # method is bytes on py3
+
+        if trace:
+            # We don't extract the context from the servlet because we can't
+            # trust the sender
+            callback = trace_servlet(servlet_classname)(callback)
+
         for path_pattern in path_patterns:
             logger.debug("Registering for %s %s", method, path_pattern.pattern)
             self.path_regexs.setdefault(method, []).append(
diff --git a/synapse/http/servlet.py b/synapse/http/servlet.py
index c186b31f59..274c1a6a87 100644
--- a/synapse/http/servlet.py
+++ b/synapse/http/servlet.py
@@ -20,7 +20,6 @@ import logging
 from canonicaljson import json
 
 from synapse.api.errors import Codes, SynapseError
-from synapse.logging.opentracing import trace_servlet
 
 logger = logging.getLogger(__name__)
 
@@ -298,10 +297,7 @@ class RestServlet(object):
                     servlet_classname = self.__class__.__name__
                     method_handler = getattr(self, "on_%s" % (method,))
                     http_server.register_paths(
-                        method,
-                        patterns,
-                        trace_servlet(servlet_classname)(method_handler),
-                        servlet_classname,
+                        method, patterns, method_handler, servlet_classname
                     )
 
         else:
diff --git a/synapse/logging/opentracing.py b/synapse/logging/opentracing.py
index 256b972aaa..7246253018 100644
--- a/synapse/logging/opentracing.py
+++ b/synapse/logging/opentracing.py
@@ -239,8 +239,7 @@ _homeserver_whitelist = None
 
 
 def only_if_tracing(func):
-    """Executes the function only if we're tracing. Otherwise return.
-    Assumes the function wrapped may return None"""
+    """Executes the function only if we're tracing. Otherwise returns None."""
 
     @wraps(func)
     def _only_if_tracing_inner(*args, **kwargs):
@@ -252,6 +251,41 @@ def only_if_tracing(func):
     return _only_if_tracing_inner
 
 
+def ensure_active_span(message, ret=None):
+    """Executes the operation only if opentracing is enabled and there is an active span.
+    If there is no active span it logs message at the error level.
+
+    Args:
+        message (str): Message which fills in "There was no active span when trying to %s"
+            in the error log if there is no active span and opentracing is enabled.
+        ret (object): return value if opentracing is None or there is no active span.
+
+    Returns (object): The result of the func or ret if opentracing is disabled or there
+        was no active span.
+    """
+
+    def ensure_active_span_inner_1(func):
+        @wraps(func)
+        def ensure_active_span_inner_2(*args, **kwargs):
+            if not opentracing:
+                return ret
+
+            if not opentracing.tracer.active_span:
+                logger.error(
+                    "There was no active span when trying to %s."
+                    " Did you forget to start one or did a context slip?",
+                    message,
+                )
+
+                return ret
+
+            return func(*args, **kwargs)
+
+        return ensure_active_span_inner_2
+
+    return ensure_active_span_inner_1
+
+
 @contextlib.contextmanager
 def _noop_context_manager(*args, **kwargs):
     """Does exactly what it says on the tin"""
@@ -319,7 +353,7 @@ def whitelisted_homeserver(destination):
     Args:
         destination (str)
         """
-    _homeserver_whitelist
+
     if _homeserver_whitelist:
         return _homeserver_whitelist.match(destination)
     return False
@@ -349,26 +383,24 @@ def start_active_span(
     if opentracing is None:
         return _noop_context_manager()
 
-    else:
-        # We need to enter the scope here for the logcontext to become active
-        return opentracing.tracer.start_active_span(
-            operation_name,
-            child_of=child_of,
-            references=references,
-            tags=tags,
-            start_time=start_time,
-            ignore_active_span=ignore_active_span,
-            finish_on_close=finish_on_close,
-        )
+    return opentracing.tracer.start_active_span(
+        operation_name,
+        child_of=child_of,
+        references=references,
+        tags=tags,
+        start_time=start_time,
+        ignore_active_span=ignore_active_span,
+        finish_on_close=finish_on_close,
+    )
 
 
 def start_active_span_follows_from(operation_name, contexts):
     if opentracing is None:
         return _noop_context_manager()
-    else:
-        references = [opentracing.follows_from(context) for context in contexts]
-        scope = start_active_span(operation_name, references=references)
-        return scope
+
+    references = [opentracing.follows_from(context) for context in contexts]
+    scope = start_active_span(operation_name, references=references)
+    return scope
 
 
 def start_active_span_from_request(
@@ -465,19 +497,19 @@ def start_active_span_from_edu(
 # Opentracing setters for tags, logs, etc
 
 
-@only_if_tracing
+@ensure_active_span("set a tag")
 def set_tag(key, value):
     """Sets a tag on the active span"""
     opentracing.tracer.active_span.set_tag(key, value)
 
 
-@only_if_tracing
+@ensure_active_span("log")
 def log_kv(key_values, timestamp=None):
     """Log to the active span"""
     opentracing.tracer.active_span.log_kv(key_values, timestamp)
 
 
-@only_if_tracing
+@ensure_active_span("set the traces operation name")
 def set_operation_name(operation_name):
     """Sets the operation name of the active span"""
     opentracing.tracer.active_span.set_operation_name(operation_name)
@@ -486,13 +518,18 @@ def set_operation_name(operation_name):
 # Injection and extraction
 
 
-@only_if_tracing
+@ensure_active_span("inject the span into a header")
 def inject_active_span_twisted_headers(headers, destination, check_destination=True):
     """
     Injects a span context into twisted headers in-place
 
     Args:
         headers (twisted.web.http_headers.Headers)
+        destination (str): address of entity receiving the span context. If check_destination
+            is true the context will only be injected if the destination matches the
+            opentracing whitelist
+        check_destination (bool): If false, destination will be ignored and the context
+            will always be injected.
         span (opentracing.Span)
 
     Returns:
@@ -517,7 +554,7 @@ def inject_active_span_twisted_headers(headers, destination, check_destination=T
         headers.addRawHeaders(key, value)
 
 
-@only_if_tracing
+@ensure_active_span("inject the span into a byte dict")
 def inject_active_span_byte_dict(headers, destination, check_destination=True):
     """
     Injects a span context into a dict where the headers are encoded as byte
@@ -525,6 +562,11 @@ def inject_active_span_byte_dict(headers, destination, check_destination=True):
 
     Args:
         headers (dict)
+        destination (str): address of entity receiving the span context. If check_destination
+            is true the context will only be injected if the destination matches the
+            opentracing whitelist
+        check_destination (bool): If false, destination will be ignored and the context
+            will always be injected.
         span (opentracing.Span)
 
     Returns:
@@ -537,7 +579,7 @@ def inject_active_span_byte_dict(headers, destination, check_destination=True):
         here:
         https://github.com/jaegertracing/jaeger-client-python/blob/master/jaeger_client/constants.py
     """
-    if not whitelisted_homeserver(destination):
+    if check_destination and not whitelisted_homeserver(destination):
         return
 
     span = opentracing.tracer.active_span
@@ -549,16 +591,18 @@ def inject_active_span_byte_dict(headers, destination, check_destination=True):
         headers[key.encode()] = [value.encode()]
 
 
-@only_if_tracing
+@ensure_active_span("inject the span into a text map")
 def inject_active_span_text_map(carrier, destination, check_destination=True):
     """
     Injects a span context into a dict
 
     Args:
         carrier (dict)
-        destination (str): the name of the remote server. The span context
-        will only be injected if the destination matches the homeserver_whitelist
-        or destination is None.
+        destination (str): address of entity receiving the span context. If check_destination
+            is true the context will only be injected if the destination matches the
+            opentracing whitelist
+        check_destination (bool): If false, destination will be ignored and the context
+            will always be injected.
 
     Returns:
         In-place modification of carrier
@@ -579,6 +623,7 @@ def inject_active_span_text_map(carrier, destination, check_destination=True):
     )
 
 
+@ensure_active_span("get the active span context as a dict", ret={})
 def get_active_span_text_map(destination=None):
     """
     Gets a span context as a dict. This can be used instead of manually
@@ -591,7 +636,7 @@ def get_active_span_text_map(destination=None):
         dict: the active span's context if opentracing is enabled, otherwise empty.
     """
 
-    if not opentracing or (destination and not whitelisted_homeserver(destination)):
+    if destination and not whitelisted_homeserver(destination):
         return {}
 
     carrier = {}
@@ -602,6 +647,7 @@ def get_active_span_text_map(destination=None):
     return carrier
 
 
+@ensure_active_span("get the span context as a string.", ret={})
 def active_span_context_as_string():
     """
     Returns:
@@ -656,15 +702,15 @@ def trace(func=None, opname=None):
         _opname = opname if opname else func.__name__
 
         @wraps(func)
-        def _trace_inner(self, *args, **kwargs):
+        def _trace_inner(*args, **kwargs):
             if opentracing is None:
-                return func(self, *args, **kwargs)
+                return func(*args, **kwargs)
 
             scope = start_active_span(_opname)
             scope.__enter__()
 
             try:
-                result = func(self, *args, **kwargs)
+                result = func(*args, **kwargs)
                 if isinstance(result, defer.Deferred):
 
                     def call_back(result):
@@ -704,13 +750,13 @@ def tag_args(func):
         return func
 
     @wraps(func)
-    def _tag_args_inner(self, *args, **kwargs):
+    def _tag_args_inner(*args, **kwargs):
         argspec = inspect.getargspec(func)
         for i, arg in enumerate(argspec.args[1:]):
             set_tag("ARG_" + arg, args[i])
         set_tag("args", args[len(argspec.args) :])
         set_tag("kwargs", kwargs)
-        return func(self, *args, **kwargs)
+        return func(*args, **kwargs)
 
     return _tag_args_inner
 
diff --git a/synapse/metrics/__init__.py b/synapse/metrics/__init__.py
index 488280b4a6..b5c9595cb9 100644
--- a/synapse/metrics/__init__.py
+++ b/synapse/metrics/__init__.py
@@ -29,11 +29,13 @@ from prometheus_client.core import REGISTRY, GaugeMetricFamily, HistogramMetricF
 
 from twisted.internet import reactor
 
+import synapse
 from synapse.metrics._exposition import (
     MetricsResource,
     generate_latest,
     start_http_server,
 )
+from synapse.util.versionstring import get_version_string
 
 logger = logging.getLogger(__name__)
 
@@ -385,6 +387,16 @@ event_processing_last_ts = Gauge("synapse_event_processing_last_ts", "", ["name"
 # finished being processed.
 event_processing_lag = Gauge("synapse_event_processing_lag", "", ["name"])
 
+# Build info of the running server.
+build_info = Gauge(
+    "synapse_build_info", "Build information", ["pythonversion", "version", "osversion"]
+)
+build_info.labels(
+    " ".join([platform.python_implementation(), platform.python_version()]),
+    get_version_string(synapse),
+    " ".join([platform.system(), platform.release()]),
+).set(1)
+
 last_ticked = time.time()
 
 
diff --git a/synapse/push/httppusher.py b/synapse/push/httppusher.py
index bd5d53af91..6299587808 100644
--- a/synapse/push/httppusher.py
+++ b/synapse/push/httppusher.py
@@ -22,6 +22,7 @@ from prometheus_client import Counter
 from twisted.internet import defer
 from twisted.internet.error import AlreadyCalled, AlreadyCancelled
 
+from synapse.logging import opentracing
 from synapse.metrics.background_process_metrics import run_as_background_process
 from synapse.push import PusherConfigException
 
@@ -194,7 +195,17 @@ class HttpPusher(object):
         )
 
         for push_action in unprocessed:
-            processed = yield self._process_one(push_action)
+            with opentracing.start_active_span(
+                "http-push",
+                tags={
+                    "authenticated_entity": self.user_id,
+                    "event_id": push_action["event_id"],
+                    "app_id": self.app_id,
+                    "app_display_name": self.app_display_name,
+                },
+            ):
+                processed = yield self._process_one(push_action)
+
             if processed:
                 http_push_processed_counter.inc()
                 self.backoff_delay = HttpPusher.INITIAL_BACKOFF_SEC
diff --git a/synapse/push/mailer.py b/synapse/push/mailer.py
index 4245ce26f3..3dfd527849 100644
--- a/synapse/push/mailer.py
+++ b/synapse/push/mailer.py
@@ -131,14 +131,11 @@ class Mailer(object):
             email_address (str): Email address we're sending the password
                 reset to
             token (str): Unique token generated by the server to verify
-                password reset email was received
+                the email was received
             client_secret (str): Unique token generated by the client to
                 group together multiple email sending attempts
             sid (str): The generated session ID
         """
-        if email.utils.parseaddr(email_address)[1] == "":
-            raise RuntimeError("Invalid 'to' email address")
-
         link = (
             self.hs.config.public_baseurl
             + "_matrix/client/unstable/password_reset/email/submit_token"
@@ -149,7 +146,34 @@ class Mailer(object):
 
         yield self.send_email(
             email_address,
-            "[%s] Password Reset Email" % self.hs.config.server_name,
+            "[%s] Password Reset" % self.hs.config.server_name,
+            template_vars,
+        )
+
+    @defer.inlineCallbacks
+    def send_registration_mail(self, email_address, token, client_secret, sid):
+        """Send an email with a registration confirmation link to a user
+
+        Args:
+            email_address (str): Email address we're sending the registration
+                link to
+            token (str): Unique token generated by the server to verify
+                the email was received
+            client_secret (str): Unique token generated by the client to
+                group together multiple email sending attempts
+            sid (str): The generated session ID
+        """
+        link = (
+            self.hs.config.public_baseurl
+            + "_matrix/client/unstable/registration/email/submit_token"
+            "?token=%s&client_secret=%s&sid=%s" % (token, client_secret, sid)
+        )
+
+        template_vars = {"link": link}
+
+        yield self.send_email(
+            email_address,
+            "[%s] Register your Email Address" % self.hs.config.server_name,
             template_vars,
         )
 
@@ -605,25 +629,50 @@ def format_ts_filter(value, format):
     return time.strftime(format, time.localtime(value / 1000))
 
 
-def load_jinja2_templates(config, template_html_name, template_text_name):
-    """Load the jinja2 email templates from disk
+def load_jinja2_templates(
+    template_dir,
+    template_filenames,
+    apply_format_ts_filter=False,
+    apply_mxc_to_http_filter=False,
+    public_baseurl=None,
+):
+    """Loads and returns one or more jinja2 templates and applies optional filters
+
+    Args:
+        template_dir (str): The directory where templates are stored
+        template_filenames (list[str]): A list of template filenames
+        apply_format_ts_filter (bool): Whether to apply a template filter that formats
+            timestamps
+        apply_mxc_to_http_filter (bool): Whether to apply a template filter that converts
+            mxc urls to http urls
+        public_baseurl (str|None): The public baseurl of the server. Required for
+            apply_mxc_to_http_filter to be enabled
 
     Returns:
-        (template_html, template_text)
+        A list of jinja2 templates corresponding to the given list of filenames,
+        with order preserved
     """
-    logger.info("loading email templates from '%s'", config.email_template_dir)
-    loader = jinja2.FileSystemLoader(config.email_template_dir)
+    logger.info(
+        "loading email templates %s from '%s'", template_filenames, template_dir
+    )
+    loader = jinja2.FileSystemLoader(template_dir)
     env = jinja2.Environment(loader=loader)
-    env.filters["format_ts"] = format_ts_filter
-    env.filters["mxc_to_http"] = _create_mxc_to_http_filter(config)
 
-    template_html = env.get_template(template_html_name)
-    template_text = env.get_template(template_text_name)
+    if apply_format_ts_filter:
+        env.filters["format_ts"] = format_ts_filter
+
+    if apply_mxc_to_http_filter and public_baseurl:
+        env.filters["mxc_to_http"] = _create_mxc_to_http_filter(public_baseurl)
+
+    templates = []
+    for template_filename in template_filenames:
+        template = env.get_template(template_filename)
+        templates.append(template)
 
-    return template_html, template_text
+    return templates
 
 
-def _create_mxc_to_http_filter(config):
+def _create_mxc_to_http_filter(public_baseurl):
     def mxc_to_http_filter(value, width, height, resize_method="crop"):
         if value[0:6] != "mxc://":
             return ""
@@ -636,7 +685,7 @@ def _create_mxc_to_http_filter(config):
 
         params = {"width": width, "height": height, "method": resize_method}
         return "%s_matrix/media/v1/thumbnail/%s?%s%s" % (
-            config.public_baseurl,
+            public_baseurl,
             serverAndMediaId,
             urllib.parse.urlencode(params),
             fragment or "",
diff --git a/synapse/push/pusher.py b/synapse/push/pusher.py
index a9c64a9c54..f277aeb131 100644
--- a/synapse/push/pusher.py
+++ b/synapse/push/pusher.py
@@ -35,6 +35,7 @@ except Exception:
 class PusherFactory(object):
     def __init__(self, hs):
         self.hs = hs
+        self.config = hs.config
 
         self.pusher_types = {"http": HttpPusher}
 
@@ -42,12 +43,16 @@ class PusherFactory(object):
         if hs.config.email_enable_notifs:
             self.mailers = {}  # app_name -> Mailer
 
-            templates = load_jinja2_templates(
-                config=hs.config,
-                template_html_name=hs.config.email_notif_template_html,
-                template_text_name=hs.config.email_notif_template_text,
+            self.notif_template_html, self.notif_template_text = load_jinja2_templates(
+                self.config.email_template_dir,
+                [
+                    self.config.email_notif_template_html,
+                    self.config.email_notif_template_text,
+                ],
+                apply_format_ts_filter=True,
+                apply_mxc_to_http_filter=True,
+                public_baseurl=self.config.public_baseurl,
             )
-            self.notif_template_html, self.notif_template_text = templates
 
             self.pusher_types["email"] = self._create_email_pusher
 
@@ -78,6 +83,6 @@ class PusherFactory(object):
         if "data" in pusherdict and "brand" in pusherdict["data"]:
             app_name = pusherdict["data"]["brand"]
         else:
-            app_name = self.hs.config.email_app_name
+            app_name = self.config.email_app_name
 
         return app_name
diff --git a/synapse/replication/http/_base.py b/synapse/replication/http/_base.py
index c4be9273f6..03560c1f0e 100644
--- a/synapse/replication/http/_base.py
+++ b/synapse/replication/http/_base.py
@@ -22,13 +22,17 @@ from six.moves import urllib
 
 from twisted.internet import defer
 
-import synapse.logging.opentracing as opentracing
 from synapse.api.errors import (
     CodeMessageException,
     HttpResponseException,
     RequestSendFailed,
     SynapseError,
 )
+from synapse.logging.opentracing import (
+    inject_active_span_byte_dict,
+    trace,
+    trace_servlet,
+)
 from synapse.util.caches.response_cache import ResponseCache
 from synapse.util.stringutils import random_string
 
@@ -129,6 +133,7 @@ class ReplicationEndpoint(object):
 
         client = hs.get_simple_http_client()
 
+        @trace(opname="outgoing_replication_request")
         @defer.inlineCallbacks
         def send_request(**kwargs):
             data = yield cls._serialize_payload(**kwargs)
@@ -167,9 +172,7 @@ class ReplicationEndpoint(object):
                 # the master, and so whether we should clean up or not.
                 while True:
                     headers = {}
-                    opentracing.inject_active_span_byte_dict(
-                        headers, None, check_destination=False
-                    )
+                    inject_active_span_byte_dict(headers, None, check_destination=False)
                     try:
                         result = yield request_func(uri, data, headers=headers)
                         break
@@ -210,13 +213,11 @@ class ReplicationEndpoint(object):
         args = "/".join("(?P<%s>[^/]+)" % (arg,) for arg in url_args)
         pattern = re.compile("^/_synapse/replication/%s/%s$" % (self.NAME, args))
 
+        handler = trace_servlet(self.__class__.__name__, extract_context=True)(handler)
+        # We don't let register paths trace this servlet using the default tracing
+        # options because we wish to extract the context explicitly.
         http_server.register_paths(
-            method,
-            [pattern],
-            opentracing.trace_servlet(self.__class__.__name__, extract_context=True)(
-                handler
-            ),
-            self.__class__.__name__,
+            method, [pattern], handler, self.__class__.__name__, trace=False
         )
 
     def _cached_handler(self, request, txn_id, **kwargs):
diff --git a/synapse/replication/http/register.py b/synapse/replication/http/register.py
index 87fe2dd9b0..38260256cf 100644
--- a/synapse/replication/http/register.py
+++ b/synapse/replication/http/register.py
@@ -106,7 +106,7 @@ class ReplicationPostRegisterActionsServlet(ReplicationEndpoint):
         self.registration_handler = hs.get_registration_handler()
 
     @staticmethod
-    def _serialize_payload(user_id, auth_result, access_token, bind_email, bind_msisdn):
+    def _serialize_payload(user_id, auth_result, access_token):
         """
         Args:
             user_id (str): The user ID that consented
@@ -114,17 +114,8 @@ class ReplicationPostRegisterActionsServlet(ReplicationEndpoint):
                 registered user.
             access_token (str|None): The access token of the newly logged in
                 device, or None if `inhibit_login` enabled.
-            bind_email (bool): Whether to bind the email with the identity
-                server
-            bind_msisdn (bool): Whether to bind the msisdn with the identity
-                server
         """
-        return {
-            "auth_result": auth_result,
-            "access_token": access_token,
-            "bind_email": bind_email,
-            "bind_msisdn": bind_msisdn,
-        }
+        return {"auth_result": auth_result, "access_token": access_token}
 
     @defer.inlineCallbacks
     def _handle_request(self, request, user_id):
@@ -132,15 +123,9 @@ class ReplicationPostRegisterActionsServlet(ReplicationEndpoint):
 
         auth_result = content["auth_result"]
         access_token = content["access_token"]
-        bind_email = content["bind_email"]
-        bind_msisdn = content["bind_msisdn"]
 
         yield self.registration_handler.post_registration_actions(
-            user_id=user_id,
-            auth_result=auth_result,
-            access_token=access_token,
-            bind_email=bind_email,
-            bind_msisdn=bind_msisdn,
+            user_id=user_id, auth_result=auth_result, access_token=access_token
         )
 
         return 200, {}
diff --git a/synapse/res/templates/password_reset.html b/synapse/res/templates/password_reset.html
index 4fa7b36734..a197bf872c 100644
--- a/synapse/res/templates/password_reset.html
+++ b/synapse/res/templates/password_reset.html
@@ -4,6 +4,6 @@
 
     <a href="{{ link }}">{{ link }}</a>
 
-    <p>If this was not you, please disregard this email and contact your server administrator. Thank you.</p>
+    <p>If this was not you, <strong>do not</strong> click the link above and instead contact your server administrator. Thank you.</p>
 </body>
 </html>
diff --git a/synapse/res/templates/password_reset.txt b/synapse/res/templates/password_reset.txt
index f0deff59a7..6aa6527560 100644
--- a/synapse/res/templates/password_reset.txt
+++ b/synapse/res/templates/password_reset.txt
@@ -3,5 +3,5 @@ was you, please click the link below to confirm resetting your password:
 
 {{ link }}
 
-If this was not you, please disregard this email and contact your server
-administrator. Thank you.
+If this was not you, DO NOT click the link above and instead contact your
+server administrator. Thank you.
diff --git a/synapse/res/templates/password_reset_failure.html b/synapse/res/templates/password_reset_failure.html
index 0b132cf8db..9e3c4446e3 100644
--- a/synapse/res/templates/password_reset_failure.html
+++ b/synapse/res/templates/password_reset_failure.html
@@ -1,6 +1,8 @@
 <html>
 <head></head>
 <body>
-<p>{{ failure_reason }}. Your password has not been reset.</p>
+<p>The request failed for the following reason: {{ failure_reason }}.</p>
+
+<p>Your password has not been reset.</p>
 </body>
 </html>
diff --git a/synapse/res/templates/registration.html b/synapse/res/templates/registration.html
new file mode 100644
index 0000000000..16730a527f
--- /dev/null
+++ b/synapse/res/templates/registration.html
@@ -0,0 +1,11 @@
+<html>
+<body>
+    <p>You have asked us to register this email with a new Matrix account. If this was you, please click the link below to confirm your email address:</p>
+
+    <a href="{{ link }}">Verify Your Email Address</a>
+
+    <p>If this was not you, you can safely disregard this email.</p>
+
+    <p>Thank you.</p>
+</body>
+</html>
diff --git a/synapse/res/templates/registration.txt b/synapse/res/templates/registration.txt
new file mode 100644
index 0000000000..cb4f16a90c
--- /dev/null
+++ b/synapse/res/templates/registration.txt
@@ -0,0 +1,10 @@
+Hello there,
+
+You have asked us to register this email with a new Matrix account. If this
+was you, please click the link below to confirm your email address:
+
+{{ link }}
+
+If this was not you, you can safely disregard this email.
+
+Thank you.
diff --git a/synapse/res/templates/registration_failure.html b/synapse/res/templates/registration_failure.html
new file mode 100644
index 0000000000..2833d79c37
--- /dev/null
+++ b/synapse/res/templates/registration_failure.html
@@ -0,0 +1,6 @@
+<html>
+<head></head>
+<body>
+<p>Validation failed for the following reason: {{ failure_reason }}.</p>
+</body>
+</html>
diff --git a/synapse/res/templates/registration_success.html b/synapse/res/templates/registration_success.html
new file mode 100644
index 0000000000..fbd6e4018f
--- /dev/null
+++ b/synapse/res/templates/registration_success.html
@@ -0,0 +1,6 @@
+<html>
+<head></head>
+<body>
+<p>Your email has now been validated, please return to your client. You may now close this window.</p>
+</body>
+</html>
diff --git a/synapse/rest/__init__.py b/synapse/rest/__init__.py
index 1d20b96d03..4a1fc2ec2b 100644
--- a/synapse/rest/__init__.py
+++ b/synapse/rest/__init__.py
@@ -73,7 +73,7 @@ class ClientRestResource(JsonResource):
 
     @staticmethod
     def register_servlets(client_resource, hs):
-        versions.register_servlets(client_resource)
+        versions.register_servlets(hs, client_resource)
 
         # Deprecated in r0
         initial_sync.register_servlets(hs, client_resource)
diff --git a/synapse/rest/client/v2_alpha/_base.py b/synapse/rest/client/v2_alpha/_base.py
index e3d59ac3ac..8250ae0ae1 100644
--- a/synapse/rest/client/v2_alpha/_base.py
+++ b/synapse/rest/client/v2_alpha/_base.py
@@ -37,6 +37,7 @@ def client_patterns(path_regex, releases=(0,), unstable=True, v1=False):
         SRE_Pattern
     """
     patterns = []
+
     if unstable:
         unstable_prefix = CLIENT_API_PREFIX + "/unstable"
         patterns.append(re.compile("^" + unstable_prefix + path_regex))
@@ -46,6 +47,7 @@ def client_patterns(path_regex, releases=(0,), unstable=True, v1=False):
     for release in releases:
         new_prefix = CLIENT_API_PREFIX + "/r%d" % (release,)
         patterns.append(re.compile("^" + new_prefix + path_regex))
+
     return patterns
 
 
diff --git a/synapse/rest/client/v2_alpha/account.py b/synapse/rest/client/v2_alpha/account.py
index 0620a4d0cf..2ea515d2f6 100644
--- a/synapse/rest/client/v2_alpha/account.py
+++ b/synapse/rest/client/v2_alpha/account.py
@@ -18,12 +18,11 @@ import logging
 
 from six.moves import http_client
 
-import jinja2
-
 from twisted.internet import defer
 
 from synapse.api.constants import LoginType
 from synapse.api.errors import Codes, SynapseError, ThreepidValidationError
+from synapse.config.emailconfig import ThreepidBehaviour
 from synapse.http.server import finish_request
 from synapse.http.servlet import (
     RestServlet,
@@ -31,8 +30,8 @@ from synapse.http.servlet import (
     parse_json_object_from_request,
     parse_string,
 )
+from synapse.push.mailer import Mailer, load_jinja2_templates
 from synapse.util.msisdn import phone_number_to_msisdn
-from synapse.util.stringutils import random_string
 from synapse.util.threepids import check_3pid_allowed
 
 from ._base import client_patterns, interactive_auth_handler
@@ -50,25 +49,28 @@ class EmailPasswordRequestTokenRestServlet(RestServlet):
         self.config = hs.config
         self.identity_handler = hs.get_handlers().identity_handler
 
-        if self.config.email_password_reset_behaviour == "local":
-            from synapse.push.mailer import Mailer, load_jinja2_templates
-
-            templates = load_jinja2_templates(
-                config=hs.config,
-                template_html_name=hs.config.email_password_reset_template_html,
-                template_text_name=hs.config.email_password_reset_template_text,
+        if self.config.threepid_behaviour_email == ThreepidBehaviour.LOCAL:
+            template_html, template_text = load_jinja2_templates(
+                self.config.email_template_dir,
+                [
+                    self.config.email_password_reset_template_html,
+                    self.config.email_password_reset_template_text,
+                ],
+                apply_format_ts_filter=True,
+                apply_mxc_to_http_filter=True,
+                public_baseurl=self.config.public_baseurl,
             )
             self.mailer = Mailer(
                 hs=self.hs,
                 app_name=self.config.email_app_name,
-                template_html=templates[0],
-                template_text=templates[1],
+                template_html=template_html,
+                template_text=template_text,
             )
 
     @defer.inlineCallbacks
     def on_POST(self, request):
-        if self.config.email_password_reset_behaviour == "off":
-            if self.config.password_resets_were_disabled_due_to_email_config:
+        if self.config.threepid_behaviour_email == ThreepidBehaviour.OFF:
+            if self.config.local_threepid_handling_disabled_due_to_email_config:
                 logger.warn(
                     "User password resets have been disabled due to lack of email config"
                 )
@@ -93,25 +95,39 @@ class EmailPasswordRequestTokenRestServlet(RestServlet):
                 Codes.THREEPID_DENIED,
             )
 
-        existingUid = yield self.hs.get_datastore().get_user_id_by_threepid(
+        existing_user_id = yield self.hs.get_datastore().get_user_id_by_threepid(
             "email", email
         )
 
-        if existingUid is None:
+        if existing_user_id is None:
             raise SynapseError(400, "Email not found", Codes.THREEPID_NOT_FOUND)
 
-        if self.config.email_password_reset_behaviour == "remote":
-            if "id_server" not in body:
-                raise SynapseError(400, "Missing 'id_server' param in body")
+        if self.config.threepid_behaviour_email == ThreepidBehaviour.REMOTE:
+            # Have the configured identity server handle the request
+            if not self.hs.config.account_threepid_delegate_email:
+                logger.warn(
+                    "No upstream email account_threepid_delegate configured on the server to "
+                    "handle this request"
+                )
+                raise SynapseError(
+                    400, "Password reset by email is not supported on this homeserver"
+                )
 
-            # Have the identity server handle the password reset flow
             ret = yield self.identity_handler.requestEmailToken(
-                body["id_server"], email, client_secret, send_attempt, next_link
+                self.hs.config.account_threepid_delegate_email,
+                email,
+                client_secret,
+                send_attempt,
+                next_link,
             )
         else:
             # Send password reset emails from Synapse
-            sid = yield self.send_password_reset(
-                email, client_secret, send_attempt, next_link
+            sid = yield self.identity_handler.send_threepid_validation(
+                email,
+                client_secret,
+                send_attempt,
+                self.mailer.send_password_reset_mail,
+                next_link,
             )
 
             # Wrap the session id in a JSON object
@@ -119,74 +135,6 @@ class EmailPasswordRequestTokenRestServlet(RestServlet):
 
         return 200, ret
 
-    @defer.inlineCallbacks
-    def send_password_reset(self, email, client_secret, send_attempt, next_link=None):
-        """Send a password reset email
-
-        Args:
-            email (str): The user's email address
-            client_secret (str): The provided client secret
-            send_attempt (int): Which send attempt this is
-
-        Returns:
-            The new session_id upon success
-
-        Raises:
-            SynapseError is an error occurred when sending the email
-        """
-        # Check that this email/client_secret/send_attempt combo is new or
-        # greater than what we've seen previously
-        session = yield self.datastore.get_threepid_validation_session(
-            "email", client_secret, address=email, validated=False
-        )
-
-        # Check to see if a session already exists and that it is not yet
-        # marked as validated
-        if session and session.get("validated_at") is None:
-            session_id = session["session_id"]
-            last_send_attempt = session["last_send_attempt"]
-
-            # Check that the send_attempt is higher than previous attempts
-            if send_attempt <= last_send_attempt:
-                # If not, just return a success without sending an email
-                return session_id
-        else:
-            # An non-validated session does not exist yet.
-            # Generate a session id
-            session_id = random_string(16)
-
-        # Generate a new validation token
-        token = random_string(32)
-
-        # Send the mail with the link containing the token, client_secret
-        # and session_id
-        try:
-            yield self.mailer.send_password_reset_mail(
-                email, token, client_secret, session_id
-            )
-        except Exception:
-            logger.exception("Error sending a password reset email to %s", email)
-            raise SynapseError(
-                500, "An error was encountered when sending the password reset email"
-            )
-
-        token_expires = (
-            self.hs.clock.time_msec() + self.config.email_validation_token_lifetime
-        )
-
-        yield self.datastore.start_or_continue_validation_session(
-            "email",
-            email,
-            session_id,
-            client_secret,
-            send_attempt,
-            next_link,
-            token,
-            token_expires,
-        )
-
-        return session_id
-
 
 class MsisdnPasswordRequestTokenRestServlet(RestServlet):
     PATTERNS = client_patterns("/account/password/msisdn/requestToken$")
@@ -202,11 +150,15 @@ class MsisdnPasswordRequestTokenRestServlet(RestServlet):
         body = parse_json_object_from_request(request)
 
         assert_params_in_dict(
-            body,
-            ["id_server", "client_secret", "country", "phone_number", "send_attempt"],
+            body, ["client_secret", "country", "phone_number", "send_attempt"]
         )
+        client_secret = body["client_secret"]
+        country = body["country"]
+        phone_number = body["phone_number"]
+        send_attempt = body["send_attempt"]
+        next_link = body.get("next_link")  # Optional param
 
-        msisdn = phone_number_to_msisdn(body["country"], body["phone_number"])
+        msisdn = phone_number_to_msisdn(country, phone_number)
 
         if not check_3pid_allowed(self.hs, "msisdn", msisdn):
             raise SynapseError(
@@ -215,12 +167,32 @@ class MsisdnPasswordRequestTokenRestServlet(RestServlet):
                 Codes.THREEPID_DENIED,
             )
 
-        existingUid = yield self.datastore.get_user_id_by_threepid("msisdn", msisdn)
+        existing_user_id = yield self.datastore.get_user_id_by_threepid(
+            "msisdn", msisdn
+        )
 
-        if existingUid is None:
+        if existing_user_id is None:
             raise SynapseError(400, "MSISDN not found", Codes.THREEPID_NOT_FOUND)
 
-        ret = yield self.identity_handler.requestMsisdnToken(**body)
+        if not self.hs.config.account_threepid_delegate_msisdn:
+            logger.warn(
+                "No upstream msisdn account_threepid_delegate configured on the server to "
+                "handle this request"
+            )
+            raise SynapseError(
+                400,
+                "Password reset by phone number is not supported on this homeserver",
+            )
+
+        ret = yield self.identity_handler.requestMsisdnToken(
+            self.hs.config.account_threepid_delegate_msisdn,
+            country,
+            phone_number,
+            client_secret,
+            send_attempt,
+            next_link,
+        )
+
         return 200, ret
 
 
@@ -241,31 +213,32 @@ class PasswordResetSubmitTokenServlet(RestServlet):
         self.auth = hs.get_auth()
         self.config = hs.config
         self.clock = hs.get_clock()
-        self.datastore = hs.get_datastore()
+        self.store = hs.get_datastore()
 
     @defer.inlineCallbacks
     def on_GET(self, request, medium):
+        # We currently only handle threepid token submissions for email
         if medium != "email":
             raise SynapseError(
                 400, "This medium is currently not supported for password resets"
             )
-        if self.config.email_password_reset_behaviour == "off":
-            if self.config.password_resets_were_disabled_due_to_email_config:
+        if self.config.threepid_behaviour_email == ThreepidBehaviour.OFF:
+            if self.config.local_threepid_handling_disabled_due_to_email_config:
                 logger.warn(
-                    "User password resets have been disabled due to lack of email config"
+                    "Password reset emails have been disabled due to lack of an email config"
                 )
             raise SynapseError(
-                400, "Email-based password resets have been disabled on this server"
+                400, "Email-based password resets are disabled on this server"
             )
 
-        sid = parse_string(request, "sid")
-        client_secret = parse_string(request, "client_secret")
-        token = parse_string(request, "token")
+        sid = parse_string(request, "sid", required=True)
+        client_secret = parse_string(request, "client_secret", required=True)
+        token = parse_string(request, "token", required=True)
 
-        # Attempt to validate a 3PID sesssion
+        # Attempt to validate a 3PID session
         try:
             # Mark the session as valid
-            next_link = yield self.datastore.validate_threepid_session(
+            next_link = yield self.store.validate_threepid_session(
                 sid, client_secret, token, self.clock.time_msec()
             )
 
@@ -282,38 +255,22 @@ class PasswordResetSubmitTokenServlet(RestServlet):
                     return None
 
             # Otherwise show the success template
-            html = self.config.email_password_reset_template_success_html_content
+            html = self.config.email_password_reset_template_success_html
             request.setResponseCode(200)
         except ThreepidValidationError as e:
+            request.setResponseCode(e.code)
+
             # Show a failure page with a reason
-            html = self.load_jinja2_template(
+            html_template, = load_jinja2_templates(
                 self.config.email_template_dir,
-                self.config.email_password_reset_template_failure_html,
-                template_vars={"failure_reason": e.msg},
+                [self.config.email_password_reset_template_failure_html],
             )
-            request.setResponseCode(e.code)
+
+            template_vars = {"failure_reason": e.msg}
+            html = html_template.render(**template_vars)
 
         request.write(html.encode("utf-8"))
         finish_request(request)
-        return None
-
-    def load_jinja2_template(self, template_dir, template_filename, template_vars):
-        """Loads a jinja2 template with variables to insert
-
-        Args:
-            template_dir (str): The directory where templates are stored
-            template_filename (str): The name of the template in the template_dir
-            template_vars (Dict): Dictionary of keys in the template
-                alongside their values to insert
-
-        Returns:
-            str containing the contents of the rendered template
-        """
-        loader = jinja2.FileSystemLoader(template_dir)
-        env = jinja2.Environment(loader=loader)
-
-        template = env.get_template(template_filename)
-        return template.render(**template_vars)
 
     @defer.inlineCallbacks
     def on_POST(self, request, medium):
@@ -325,7 +282,7 @@ class PasswordResetSubmitTokenServlet(RestServlet):
         body = parse_json_object_from_request(request)
         assert_params_in_dict(body, ["sid", "client_secret", "token"])
 
-        valid, _ = yield self.datastore.validate_threepid_validation_token(
+        valid, _ = yield self.store.validate_threepid_session(
             body["sid"], body["client_secret"], body["token"], self.clock.time_msec()
         )
         response_code = 200 if valid else 400
@@ -371,7 +328,6 @@ class PasswordRestServlet(RestServlet):
                 [[LoginType.EMAIL_IDENTITY], [LoginType.MSISDN]],
                 body,
                 self.hs.get_ip_from_request(request),
-                password_servlet=True,
             )
 
             if LoginType.EMAIL_IDENTITY in result:
@@ -454,10 +410,11 @@ class EmailThreepidRequestTokenRestServlet(RestServlet):
     PATTERNS = client_patterns("/account/3pid/email/requestToken$")
 
     def __init__(self, hs):
-        self.hs = hs
         super(EmailThreepidRequestTokenRestServlet, self).__init__()
+        self.hs = hs
+        self.config = hs.config
         self.identity_handler = hs.get_handlers().identity_handler
-        self.datastore = self.hs.get_datastore()
+        self.store = self.hs.get_datastore()
 
     @defer.inlineCallbacks
     def on_POST(self, request):
@@ -465,22 +422,29 @@ class EmailThreepidRequestTokenRestServlet(RestServlet):
         assert_params_in_dict(
             body, ["id_server", "client_secret", "email", "send_attempt"]
         )
+        id_server = "https://" + body["id_server"]  # Assume https
+        client_secret = body["client_secret"]
+        email = body["email"]
+        send_attempt = body["send_attempt"]
+        next_link = body.get("next_link")  # Optional param
 
-        if not check_3pid_allowed(self.hs, "email", body["email"]):
+        if not check_3pid_allowed(self.hs, "email", email):
             raise SynapseError(
                 403,
                 "Your email domain is not authorized on this server",
                 Codes.THREEPID_DENIED,
             )
 
-        existingUid = yield self.datastore.get_user_id_by_threepid(
+        existing_user_id = yield self.store.get_user_id_by_threepid(
             "email", body["email"]
         )
 
-        if existingUid is not None:
+        if existing_user_id is not None:
             raise SynapseError(400, "Email is already in use", Codes.THREEPID_IN_USE)
 
-        ret = yield self.identity_handler.requestEmailToken(**body)
+        ret = yield self.identity_handler.requestEmailToken(
+            id_server, email, client_secret, send_attempt, next_link
+        )
         return 200, ret
 
 
@@ -490,8 +454,8 @@ class MsisdnThreepidRequestTokenRestServlet(RestServlet):
     def __init__(self, hs):
         self.hs = hs
         super(MsisdnThreepidRequestTokenRestServlet, self).__init__()
+        self.store = self.hs.get_datastore()
         self.identity_handler = hs.get_handlers().identity_handler
-        self.datastore = self.hs.get_datastore()
 
     @defer.inlineCallbacks
     def on_POST(self, request):
@@ -500,8 +464,14 @@ class MsisdnThreepidRequestTokenRestServlet(RestServlet):
             body,
             ["id_server", "client_secret", "country", "phone_number", "send_attempt"],
         )
+        id_server = "https://" + body["id_server"]  # Assume https
+        client_secret = body["client_secret"]
+        country = body["country"]
+        phone_number = body["phone_number"]
+        send_attempt = body["send_attempt"]
+        next_link = body.get("next_link")  # Optional param
 
-        msisdn = phone_number_to_msisdn(body["country"], body["phone_number"])
+        msisdn = phone_number_to_msisdn(country, phone_number)
 
         if not check_3pid_allowed(self.hs, "msisdn", msisdn):
             raise SynapseError(
@@ -510,12 +480,14 @@ class MsisdnThreepidRequestTokenRestServlet(RestServlet):
                 Codes.THREEPID_DENIED,
             )
 
-        existingUid = yield self.datastore.get_user_id_by_threepid("msisdn", msisdn)
+        existing_user_id = yield self.store.get_user_id_by_threepid("msisdn", msisdn)
 
-        if existingUid is not None:
+        if existing_user_id is not None:
             raise SynapseError(400, "MSISDN is already in use", Codes.THREEPID_IN_USE)
 
-        ret = yield self.identity_handler.requestMsisdnToken(**body)
+        ret = yield self.identity_handler.requestMsisdnToken(
+            id_server, country, phone_number, client_secret, send_attempt, next_link
+        )
         return 200, ret
 
 
@@ -542,15 +514,17 @@ class ThreepidRestServlet(RestServlet):
     def on_POST(self, request):
         body = parse_json_object_from_request(request)
 
-        threePidCreds = body.get("threePidCreds")
-        threePidCreds = body.get("three_pid_creds", threePidCreds)
-        if threePidCreds is None:
-            raise SynapseError(400, "Missing param", Codes.MISSING_PARAM)
+        threepid_creds = body.get("threePidCreds") or body.get("three_pid_creds")
+        if threepid_creds is None:
+            raise SynapseError(
+                400, "Missing param three_pid_creds", Codes.MISSING_PARAM
+            )
 
         requester = yield self.auth.get_user_by_req(request)
         user_id = requester.user.to_string()
 
-        threepid = yield self.identity_handler.threepid_from_creds(threePidCreds)
+        # Specify None as the identity server to retrieve it from the request body instead
+        threepid = yield self.identity_handler.threepid_from_creds(None, threepid_creds)
 
         if not threepid:
             raise SynapseError(400, "Failed to auth 3pid", Codes.THREEPID_AUTH_FAILED)
@@ -566,11 +540,43 @@ class ThreepidRestServlet(RestServlet):
 
         if "bind" in body and body["bind"]:
             logger.debug("Binding threepid %s to %s", threepid, user_id)
-            yield self.identity_handler.bind_threepid(threePidCreds, user_id)
+            yield self.identity_handler.bind_threepid(threepid_creds, user_id)
 
         return 200, {}
 
 
+class ThreepidUnbindRestServlet(RestServlet):
+    PATTERNS = client_patterns("/account/3pid/unbind$")
+
+    def __init__(self, hs):
+        super(ThreepidUnbindRestServlet, self).__init__()
+        self.hs = hs
+        self.identity_handler = hs.get_handlers().identity_handler
+        self.auth = hs.get_auth()
+        self.datastore = self.hs.get_datastore()
+
+    @defer.inlineCallbacks
+    def on_POST(self, request):
+        """Unbind the given 3pid from a specific identity server, or identity servers that are
+        known to have this 3pid bound
+        """
+        requester = yield self.auth.get_user_by_req(request)
+        body = parse_json_object_from_request(request)
+        assert_params_in_dict(body, ["medium", "address"])
+
+        medium = body.get("medium")
+        address = body.get("address")
+        id_server = body.get("id_server")
+
+        # Attempt to unbind the threepid from an identity server. If id_server is None, try to
+        # unbind from all identity servers this threepid has been added to in the past
+        result = yield self.identity_handler.try_unbind_threepid(
+            requester.user.to_string(),
+            {"address": address, "medium": medium, "id_server": id_server},
+        )
+        return 200, {"id_server_unbind_result": "success" if result else "no-support"}
+
+
 class ThreepidDeleteRestServlet(RestServlet):
     PATTERNS = client_patterns("/account/3pid/delete$")
 
@@ -629,5 +635,6 @@ def register_servlets(hs, http_server):
     EmailThreepidRequestTokenRestServlet(hs).register(http_server)
     MsisdnThreepidRequestTokenRestServlet(hs).register(http_server)
     ThreepidRestServlet(hs).register(http_server)
+    ThreepidUnbindRestServlet(hs).register(http_server)
     ThreepidDeleteRestServlet(hs).register(http_server)
     WhoamiRestServlet(hs).register(http_server)
diff --git a/synapse/rest/client/v2_alpha/register.py b/synapse/rest/client/v2_alpha/register.py
index 107854c669..5c7a5f3579 100644
--- a/synapse/rest/client/v2_alpha/register.py
+++ b/synapse/rest/client/v2_alpha/register.py
@@ -28,16 +28,20 @@ from synapse.api.errors import (
     Codes,
     LimitExceededError,
     SynapseError,
+    ThreepidValidationError,
     UnrecognizedRequestError,
 )
+from synapse.config.emailconfig import ThreepidBehaviour
 from synapse.config.ratelimiting import FederationRateLimitConfig
 from synapse.config.server import is_threepid_reserved
+from synapse.http.server import finish_request
 from synapse.http.servlet import (
     RestServlet,
     assert_params_in_dict,
     parse_json_object_from_request,
     parse_string,
 )
+from synapse.push.mailer import load_jinja2_templates
 from synapse.util.msisdn import phone_number_to_msisdn
 from synapse.util.ratelimitutils import FederationRateLimiter
 from synapse.util.threepids import check_3pid_allowed
@@ -70,30 +74,92 @@ class EmailRegisterRequestTokenRestServlet(RestServlet):
         super(EmailRegisterRequestTokenRestServlet, self).__init__()
         self.hs = hs
         self.identity_handler = hs.get_handlers().identity_handler
+        self.config = hs.config
+
+        if self.hs.config.threepid_behaviour_email == ThreepidBehaviour.LOCAL:
+            from synapse.push.mailer import Mailer, load_jinja2_templates
+
+            template_html, template_text = load_jinja2_templates(
+                self.config.email_template_dir,
+                [
+                    self.config.email_registration_template_html,
+                    self.config.email_registration_template_text,
+                ],
+                apply_format_ts_filter=True,
+                apply_mxc_to_http_filter=True,
+                public_baseurl=self.config.public_baseurl,
+            )
+            self.mailer = Mailer(
+                hs=self.hs,
+                app_name=self.config.email_app_name,
+                template_html=template_html,
+                template_text=template_text,
+            )
 
     @defer.inlineCallbacks
     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(
+                    "Email registration has been disabled due to lack of email config"
+                )
+            raise SynapseError(
+                400, "Email-based registration has been disabled on this server"
+            )
         body = parse_json_object_from_request(request)
 
-        assert_params_in_dict(
-            body, ["id_server", "client_secret", "email", "send_attempt"]
-        )
+        assert_params_in_dict(body, ["client_secret", "email", "send_attempt"])
 
-        if not check_3pid_allowed(self.hs, "email", body["email"]):
+        # Extract params from body
+        client_secret = body["client_secret"]
+        email = body["email"]
+        send_attempt = body["send_attempt"]
+        next_link = body.get("next_link")  # Optional param
+
+        if not check_3pid_allowed(self.hs, "email", email):
             raise SynapseError(
                 403,
                 "Your email domain is not authorized to register on this server",
                 Codes.THREEPID_DENIED,
             )
 
-        existingUid = yield self.hs.get_datastore().get_user_id_by_threepid(
+        existing_user_id = yield self.hs.get_datastore().get_user_id_by_threepid(
             "email", body["email"]
         )
 
-        if existingUid is not None:
+        if existing_user_id is not None:
             raise SynapseError(400, "Email is already in use", Codes.THREEPID_IN_USE)
 
-        ret = yield self.identity_handler.requestEmailToken(**body)
+        if self.config.threepid_behaviour_email == ThreepidBehaviour.REMOTE:
+            if not self.hs.config.account_threepid_delegate_email:
+                logger.warn(
+                    "No upstream email account_threepid_delegate configured on the server to "
+                    "handle this request"
+                )
+                raise SynapseError(
+                    400, "Registration by email is not supported on this homeserver"
+                )
+
+            ret = yield self.identity_handler.requestEmailToken(
+                self.hs.config.account_threepid_delegate_email,
+                email,
+                client_secret,
+                send_attempt,
+                next_link,
+            )
+        else:
+            # Send registration emails from Synapse
+            sid = yield self.identity_handler.send_threepid_validation(
+                email,
+                client_secret,
+                send_attempt,
+                self.mailer.send_registration_mail,
+                next_link,
+            )
+
+            # Wrap the session id in a JSON object
+            ret = {"sid": sid}
+
         return 200, ret
 
 
@@ -114,11 +180,15 @@ class MsisdnRegisterRequestTokenRestServlet(RestServlet):
         body = parse_json_object_from_request(request)
 
         assert_params_in_dict(
-            body,
-            ["id_server", "client_secret", "country", "phone_number", "send_attempt"],
+            body, ["client_secret", "country", "phone_number", "send_attempt"]
         )
+        client_secret = body["client_secret"]
+        country = body["country"]
+        phone_number = body["phone_number"]
+        send_attempt = body["send_attempt"]
+        next_link = body.get("next_link")  # Optional param
 
-        msisdn = phone_number_to_msisdn(body["country"], body["phone_number"])
+        msisdn = phone_number_to_msisdn(country, phone_number)
 
         if not check_3pid_allowed(self.hs, "msisdn", msisdn):
             raise SynapseError(
@@ -127,19 +197,114 @@ class MsisdnRegisterRequestTokenRestServlet(RestServlet):
                 Codes.THREEPID_DENIED,
             )
 
-        existingUid = yield self.hs.get_datastore().get_user_id_by_threepid(
+        existing_user_id = yield self.hs.get_datastore().get_user_id_by_threepid(
             "msisdn", msisdn
         )
 
-        if existingUid is not None:
+        if existing_user_id is not None:
             raise SynapseError(
                 400, "Phone number is already in use", Codes.THREEPID_IN_USE
             )
 
-        ret = yield self.identity_handler.requestMsisdnToken(**body)
+        if not self.hs.config.account_threepid_delegate_msisdn:
+            logger.warn(
+                "No upstream msisdn account_threepid_delegate configured on the server to "
+                "handle this request"
+            )
+            raise SynapseError(
+                400, "Registration by phone number is not supported on this homeserver"
+            )
+
+        ret = yield self.identity_handler.requestMsisdnToken(
+            self.hs.config.account_threepid_delegate_msisdn,
+            country,
+            phone_number,
+            client_secret,
+            send_attempt,
+            next_link,
+        )
+
         return 200, ret
 
 
+class RegistrationSubmitTokenServlet(RestServlet):
+    """Handles registration 3PID validation token submission"""
+
+    PATTERNS = client_patterns(
+        "/registration/(?P<medium>[^/]*)/submit_token$", releases=(), unstable=True
+    )
+
+    def __init__(self, hs):
+        """
+        Args:
+            hs (synapse.server.HomeServer): server
+        """
+        super(RegistrationSubmitTokenServlet, self).__init__()
+        self.hs = hs
+        self.auth = hs.get_auth()
+        self.config = hs.config
+        self.clock = hs.get_clock()
+        self.store = hs.get_datastore()
+
+    @defer.inlineCallbacks
+    def on_GET(self, request, medium):
+        if medium != "email":
+            raise SynapseError(
+                400, "This medium is currently not supported for registration"
+            )
+        if self.config.threepid_behaviour_email == ThreepidBehaviour.OFF:
+            if self.config.local_threepid_handling_disabled_due_to_email_config:
+                logger.warn(
+                    "User registration via email has been disabled due to lack of email config"
+                )
+            raise SynapseError(
+                400, "Email-based registration is disabled on this server"
+            )
+
+        sid = parse_string(request, "sid", required=True)
+        client_secret = parse_string(request, "client_secret", required=True)
+        token = parse_string(request, "token", required=True)
+
+        # Attempt to validate a 3PID session
+        try:
+            # Mark the session as valid
+            next_link = yield self.store.validate_threepid_session(
+                sid, client_secret, token, self.clock.time_msec()
+            )
+
+            # Perform a 302 redirect if next_link is set
+            if next_link:
+                if next_link.startswith("file:///"):
+                    logger.warn(
+                        "Not redirecting to next_link as it is a local file: address"
+                    )
+                else:
+                    request.setResponseCode(302)
+                    request.setHeader("Location", next_link)
+                    finish_request(request)
+                    return None
+
+            # Otherwise show the success template
+            html = self.config.email_registration_template_success_html_content
+
+            request.setResponseCode(200)
+        except ThreepidValidationError as e:
+            # Show a failure page with a reason
+            request.setResponseCode(e.code)
+
+            # Show a failure page with a reason
+            html_template, = load_jinja2_templates(
+                self.config.email_template_dir,
+                [self.config.email_registration_template_failure_html],
+            )
+
+            template_vars = {"failure_reason": e.msg}
+            html = html_template.render(**template_vars)
+
+        request.write(html.encode("utf-8"))
+        finish_request(request)
+
+
 class UsernameAvailabilityRestServlet(RestServlet):
     PATTERNS = client_patterns("/register/available")
 
@@ -438,11 +603,11 @@ class RegisterRestServlet(RestServlet):
                         medium = auth_result[login_type]["medium"]
                         address = auth_result[login_type]["address"]
 
-                        existingUid = yield self.store.get_user_id_by_threepid(
+                        existing_user_id = yield self.store.get_user_id_by_threepid(
                             medium, address
                         )
 
-                        if existingUid is not None:
+                        if existing_user_id is not None:
                             raise SynapseError(
                                 400,
                                 "%s is already in use" % medium,
@@ -481,8 +646,6 @@ class RegisterRestServlet(RestServlet):
                 user_id=registered_user_id,
                 auth_result=auth_result,
                 access_token=return_dict.get("access_token"),
-                bind_email=params.get("bind_email"),
-                bind_msisdn=params.get("bind_msisdn"),
             )
 
         return 200, return_dict
@@ -552,4 +715,5 @@ def register_servlets(hs, http_server):
     EmailRegisterRequestTokenRestServlet(hs).register(http_server)
     MsisdnRegisterRequestTokenRestServlet(hs).register(http_server)
     UsernameAvailabilityRestServlet(hs).register(http_server)
+    RegistrationSubmitTokenServlet(hs).register(http_server)
     RegisterRestServlet(hs).register(http_server)
diff --git a/synapse/rest/client/versions.py b/synapse/rest/client/versions.py
index 0e09191632..0058b6b459 100644
--- a/synapse/rest/client/versions.py
+++ b/synapse/rest/client/versions.py
@@ -24,6 +24,10 @@ logger = logging.getLogger(__name__)
 class VersionsRestServlet(RestServlet):
     PATTERNS = [re.compile("^/_matrix/client/versions$")]
 
+    def __init__(self, hs):
+        super(VersionsRestServlet, self).__init__()
+        self.config = hs.config
+
     def on_GET(self, request):
         return (
             200,
@@ -49,5 +53,5 @@ class VersionsRestServlet(RestServlet):
         )
 
 
-def register_servlets(http_server):
-    VersionsRestServlet().register(http_server)
+def register_servlets(hs, http_server):
+    VersionsRestServlet(hs).register(http_server)
diff --git a/synapse/storage/devices.py b/synapse/storage/devices.py
index 41f62828bd..79a58df591 100644
--- a/synapse/storage/devices.py
+++ b/synapse/storage/devices.py
@@ -856,7 +856,7 @@ class DeviceStore(DeviceWorkerStore, BackgroundUpdateStore):
                     "ts": now,
                     "opentracing_context": json.dumps(context)
                     if whitelisted_homeserver(destination)
-                    else None,
+                    else "{}",
                 }
                 for destination in hosts
                 for device_id in device_ids
diff --git a/synapse/storage/events.py b/synapse/storage/events.py
index 32050868ff..ddf7ab6479 100644
--- a/synapse/storage/events.py
+++ b/synapse/storage/events.py
@@ -23,7 +23,7 @@ from functools import wraps
 from six import iteritems, text_type
 from six.moves import range
 
-from canonicaljson import json
+from canonicaljson import encode_canonical_json, json
 from prometheus_client import Counter, Histogram
 
 from twisted.internet import defer
@@ -33,6 +33,7 @@ from synapse.api.constants import 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
@@ -262,6 +263,14 @@ class EventsStore(
 
         hs.get_clock().looping_call(read_forward_extremities, 60 * 60 * 1000)
 
+        def _censor_redactions():
+            return run_as_background_process(
+                "_censor_redactions", self._censor_redactions
+            )
+
+        if self.hs.config.redaction_retention_period is not None:
+            hs.get_clock().looping_call(_censor_redactions, 5 * 60 * 1000)
+
     @defer.inlineCallbacks
     def _read_forward_extremities(self):
         def fetch(txn):
@@ -1549,6 +1558,98 @@ class EventsStore(
         )
 
     @defer.inlineCallbacks
+    def _censor_redactions(self):
+        """Censors all redactions older than the configured period that haven't
+        been censored yet.
+
+        By censor we mean update the event_json table with the redacted event.
+
+        Returns:
+            Deferred
+        """
+
+        if self.hs.config.redaction_retention_period is None:
+            return
+
+        max_pos = yield self.find_first_stream_ordering_after_ts(
+            self._clock.time_msec() - self.hs.config.redaction_retention_period
+        )
+
+        # We fetch all redactions that:
+        #   1. point to an event we have,
+        #   2. has a stream ordering from before the cut off, and
+        #   3. we haven't yet censored.
+        #
+        # This is limited to 100 events to ensure that we don't try and do too
+        # much at once. We'll get called again so this should eventually catch
+        # up.
+        #
+        # We use the range [-max_pos, max_pos] to handle backfilled events,
+        # which are given negative stream ordering.
+        sql = """
+            SELECT redact_event.event_id, redacts FROM redactions
+            INNER JOIN events AS redact_event USING (event_id)
+            INNER JOIN events AS original_event ON (
+                redact_event.room_id = original_event.room_id
+                AND redacts = original_event.event_id
+            )
+            WHERE NOT have_censored
+            AND ? <= redact_event.stream_ordering AND redact_event.stream_ordering <= ?
+            ORDER BY redact_event.stream_ordering ASC
+            LIMIT ?
+        """
+
+        rows = yield self._execute(
+            "_censor_redactions_fetch", None, sql, -max_pos, max_pos, 100
+        )
+
+        updates = []
+
+        for redaction_id, event_id in rows:
+            redaction_event = yield self.get_event(redaction_id, allow_none=True)
+            original_event = yield self.get_event(
+                event_id, allow_rejected=True, allow_none=True
+            )
+
+            # The SQL above ensures that we have both the redaction and
+            # original event, so if the `get_event` calls return None it
+            # means that the redaction wasn't allowed. Either way we know that
+            # the result won't change so we mark the fact that we've checked.
+            if (
+                redaction_event
+                and original_event
+                and original_event.internal_metadata.is_redacted()
+            ):
+                # Redaction was allowed
+                pruned_json = encode_canonical_json(
+                    prune_event_dict(original_event.get_dict())
+                )
+            else:
+                # Redaction wasn't allowed
+                pruned_json = None
+
+            updates.append((redaction_id, event_id, pruned_json))
+
+        def _update_censor_txn(txn):
+            for redaction_id, event_id, pruned_json in updates:
+                if pruned_json:
+                    self._simple_update_one_txn(
+                        txn,
+                        table="event_json",
+                        keyvalues={"event_id": event_id},
+                        updatevalues={"json": pruned_json},
+                    )
+
+                self._simple_update_one_txn(
+                    txn,
+                    table="redactions",
+                    keyvalues={"event_id": redaction_id},
+                    updatevalues={"have_censored": True},
+                )
+
+        yield self.runInteraction("_update_censor_txn", _update_censor_txn)
+
+    @defer.inlineCallbacks
     def count_daily_messages(self):
         """
         Returns an estimate of the number of messages sent in the last day.
@@ -2270,8 +2371,9 @@ class EventsStore(
             "room_aliases",
             "room_depth",
             "room_memberships",
-            "room_state",
-            "room_stats",
+            "room_stats_state",
+            "room_stats_current",
+            "room_stats_historical",
             "room_stats_earliest_token",
             "rooms",
             "stream_ordering_to_exterm",
diff --git a/synapse/storage/registration.py b/synapse/storage/registration.py
index 3f50324253..109052fa41 100644
--- a/synapse/storage/registration.py
+++ b/synapse/storage/registration.py
@@ -323,6 +323,19 @@ class RegistrationWorkerStore(SQLBaseStore):
         return None
 
     @cachedInlineCallbacks()
+    def is_real_user(self, user_id):
+        """Determines if the user is a real user, ie does not have a 'user_type'.
+
+        Args:
+            user_id (str): user id to test
+
+        Returns:
+            Deferred[bool]: True if user 'user_type' is null or empty string
+        """
+        res = yield self.runInteraction("is_real_user", self.is_real_user_txn, user_id)
+        return res
+
+    @cachedInlineCallbacks()
     def is_support_user(self, user_id):
         """Determines if the user is of type UserTypes.SUPPORT
 
@@ -337,6 +350,16 @@ class RegistrationWorkerStore(SQLBaseStore):
         )
         return res
 
+    def is_real_user_txn(self, txn, user_id):
+        res = self._simple_select_one_onecol_txn(
+            txn=txn,
+            table="users",
+            keyvalues={"name": user_id},
+            retcol="user_type",
+            allow_none=True,
+        )
+        return res is None
+
     def is_support_user_txn(self, txn, user_id):
         res = self._simple_select_one_onecol_txn(
             txn=txn,
@@ -422,6 +445,20 @@ class RegistrationWorkerStore(SQLBaseStore):
         return ret
 
     @defer.inlineCallbacks
+    def count_real_users(self):
+        """Counts all users without a special user_type registered on the homeserver."""
+
+        def _count_users(txn):
+            txn.execute("SELECT COUNT(*) AS users FROM users where user_type is null")
+            rows = self.cursor_to_dict(txn)
+            if rows:
+                return rows[0]["users"]
+            return 0
+
+        ret = yield self.runInteraction("count_real_users", _count_users)
+        return ret
+
+    @defer.inlineCallbacks
     def find_next_generated_user_id_localpart(self):
         """
         Gets the localpart of the next generated user ID.
@@ -614,6 +651,85 @@ class RegistrationWorkerStore(SQLBaseStore):
         # Convert the integer into a boolean.
         return res == 1
 
+    def get_threepid_validation_session(
+        self, medium, client_secret, address=None, sid=None, validated=True
+    ):
+        """Gets a session_id and last_send_attempt (if available) for a
+        client_secret/medium/(address|session_id) combo
+
+        Args:
+            medium (str|None): The medium of the 3PID
+            address (str|None): The address of the 3PID
+            sid (str|None): The ID of the validation session
+            client_secret (str|None): A unique string provided by the client to
+                help identify this validation attempt
+            validated (bool|None): Whether sessions should be filtered by
+                whether they have been validated already or not. None to
+                perform no filtering
+
+        Returns:
+            deferred {str, int}|None: A dict containing the
+                latest session_id and send_attempt count for this 3PID.
+                Otherwise None if there hasn't been a previous attempt
+        """
+        keyvalues = {"medium": medium, "client_secret": client_secret}
+        if address:
+            keyvalues["address"] = address
+        if sid:
+            keyvalues["session_id"] = sid
+
+        assert address or sid
+
+        def get_threepid_validation_session_txn(txn):
+            sql = """
+                SELECT address, session_id, medium, client_secret,
+                last_send_attempt, validated_at
+                FROM threepid_validation_session WHERE %s
+                """ % (
+                " AND ".join("%s = ?" % k for k in iterkeys(keyvalues)),
+            )
+
+            if validated is not None:
+                sql += " AND validated_at IS " + ("NOT NULL" if validated else "NULL")
+
+            sql += " LIMIT 1"
+
+            txn.execute(sql, list(keyvalues.values()))
+            rows = self.cursor_to_dict(txn)
+            if not rows:
+                return None
+
+            return rows[0]
+
+        return self.runInteraction(
+            "get_threepid_validation_session", get_threepid_validation_session_txn
+        )
+
+    def delete_threepid_session(self, session_id):
+        """Removes a threepid validation session from the database. This can
+        be done after validation has been performed and whatever action was
+        waiting on it has been carried out
+
+        Args:
+            session_id (str): The ID of the session to delete
+        """
+
+        def delete_threepid_session_txn(txn):
+            self._simple_delete_txn(
+                txn,
+                table="threepid_validation_token",
+                keyvalues={"session_id": session_id},
+            )
+            self._simple_delete_txn(
+                txn,
+                table="threepid_validation_session",
+                keyvalues={"session_id": session_id},
+            )
+
+        return self.runInteraction(
+            "delete_threepid_session", delete_threepid_session_txn
+        )
+
 
 class RegistrationStore(
     RegistrationWorkerStore, background_updates.BackgroundUpdateStore
@@ -869,6 +985,17 @@ class RegistrationStore(
                 (user_id_obj.localpart, create_profile_with_displayname),
             )
 
+        if self.hs.config.stats_enabled:
+            # we create a new completed user statistics row
+
+            # we don't strictly need current_token since this user really can't
+            # have any state deltas before now (as it is a new user), but still,
+            # we include it for completeness.
+            current_token = self._get_max_stream_id_in_current_state_deltas_txn(txn)
+            self._update_stats_delta_txn(
+                txn, now, "user", user_id, {}, complete_with_stream_id=current_token
+            )
+
         self._invalidate_cache_and_stream(txn, self.get_user_by_id, (user_id,))
         txn.call_after(self.is_guest.invalidate, (user_id,))
 
@@ -1071,60 +1198,6 @@ class RegistrationStore(
 
         return 1
 
-    def get_threepid_validation_session(
-        self, medium, client_secret, address=None, sid=None, validated=True
-    ):
-        """Gets a session_id and last_send_attempt (if available) for a
-        client_secret/medium/(address|session_id) combo
-
-        Args:
-            medium (str|None): The medium of the 3PID
-            address (str|None): The address of the 3PID
-            sid (str|None): The ID of the validation session
-            client_secret (str|None): A unique string provided by the client to
-                help identify this validation attempt
-            validated (bool|None): Whether sessions should be filtered by
-                whether they have been validated already or not. None to
-                perform no filtering
-
-        Returns:
-            deferred {str, int}|None: A dict containing the
-                latest session_id and send_attempt count for this 3PID.
-                Otherwise None if there hasn't been a previous attempt
-        """
-        keyvalues = {"medium": medium, "client_secret": client_secret}
-        if address:
-            keyvalues["address"] = address
-        if sid:
-            keyvalues["session_id"] = sid
-
-        assert address or sid
-
-        def get_threepid_validation_session_txn(txn):
-            sql = """
-                SELECT address, session_id, medium, client_secret,
-                last_send_attempt, validated_at
-                FROM threepid_validation_session WHERE %s
-                """ % (
-                " AND ".join("%s = ?" % k for k in iterkeys(keyvalues)),
-            )
-
-            if validated is not None:
-                sql += " AND validated_at IS " + ("NOT NULL" if validated else "NULL")
-
-            sql += " LIMIT 1"
-
-            txn.execute(sql, list(keyvalues.values()))
-            rows = self.cursor_to_dict(txn)
-            if not rows:
-                return None
-
-            return rows[0]
-
-        return self.runInteraction(
-            "get_threepid_validation_session", get_threepid_validation_session_txn
-        )
-
     def validate_threepid_session(self, session_id, client_secret, token, current_ts):
         """Attempt to validate a threepid session using a token
 
@@ -1140,6 +1213,7 @@ class RegistrationStore(
             deferred str|None: A str representing a link to redirect the user
             to if there is one.
         """
+
         # Insert everything into a transaction in order to run atomically
         def validate_threepid_session_txn(txn):
             row = self._simple_select_one_txn(
@@ -1311,31 +1385,6 @@ class RegistrationStore(
             self.clock.time_msec(),
         )
 
-    def delete_threepid_session(self, session_id):
-        """Removes a threepid validation session from the database. This can
-        be done after validation has been performed and whatever action was
-        waiting on it has been carried out
-
-        Args:
-            session_id (str): The ID of the session to delete
-        """
-
-        def delete_threepid_session_txn(txn):
-            self._simple_delete_txn(
-                txn,
-                table="threepid_validation_token",
-                keyvalues={"session_id": session_id},
-            )
-            self._simple_delete_txn(
-                txn,
-                table="threepid_validation_session",
-                keyvalues={"session_id": session_id},
-            )
-
-        return self.runInteraction(
-            "delete_threepid_session", delete_threepid_session_txn
-        )
-
     def set_user_deactivated_status_txn(self, txn, user_id, deactivated):
         self._simple_update_one_txn(
             txn=txn,
diff --git a/synapse/storage/roommember.py b/synapse/storage/roommember.py
index eecb276465..4df8ebdacd 100644
--- a/synapse/storage/roommember.py
+++ b/synapse/storage/roommember.py
@@ -24,8 +24,10 @@ from canonicaljson import json
 from twisted.internet import defer
 
 from synapse.api.constants import EventTypes, Membership
+from synapse.metrics import LaterGauge
 from synapse.metrics.background_process_metrics import run_as_background_process
 from synapse.storage._base import LoggingTransaction
+from synapse.storage.engines import Sqlite3Engine
 from synapse.storage.events_worker import EventsWorkerStore
 from synapse.types import get_domain_from_id
 from synapse.util.async_helpers import Linearizer
@@ -74,6 +76,63 @@ class RoomMemberWorkerStore(EventsWorkerStore):
         self._check_safe_current_state_events_membership_updated_txn(txn)
         txn.close()
 
+        if self.hs.config.metrics_flags.known_servers:
+            self._known_servers_count = 1
+            self.hs.get_clock().looping_call(
+                run_as_background_process,
+                60 * 1000,
+                "_count_known_servers",
+                self._count_known_servers,
+            )
+            self.hs.get_clock().call_later(
+                1000,
+                run_as_background_process,
+                "_count_known_servers",
+                self._count_known_servers,
+            )
+            LaterGauge(
+                "synapse_federation_known_servers",
+                "",
+                [],
+                lambda: self._known_servers_count,
+            )
+
+    @defer.inlineCallbacks
+    def _count_known_servers(self):
+        """
+        Count the servers that this server knows about.
+
+        The statistic is stored on the class for the
+        `synapse_federation_known_servers` LaterGauge to collect.
+        """
+
+        def _transact(txn):
+            if isinstance(self.database_engine, Sqlite3Engine):
+                query = """
+                    SELECT COUNT(DISTINCT substr(out.user_id, pos+1))
+                    FROM (
+                        SELECT rm.user_id as user_id, instr(rm.user_id, ':')
+                            AS pos FROM room_memberships as rm
+                        INNER JOIN current_state_events as c ON rm.event_id = c.event_id
+                        WHERE c.type = 'm.room.member'
+                    ) as out
+                """
+            else:
+                query = """
+                    SELECT COUNT(DISTINCT split_part(state_key, ':', 2))
+                    FROM current_state_events
+                    WHERE type = 'm.room.member' AND membership = 'join';
+                """
+            txn.execute(query)
+            return list(txn)[0][0]
+
+        count = yield self.runInteraction("get_known_servers", _transact)
+
+        # We always know about ourselves, even if we have nothing in
+        # room_memberships (for example, the server is new).
+        self._known_servers_count = max([count, 1])
+        return self._known_servers_count
+
     def _check_safe_current_state_events_membership_updated_txn(self, txn):
         """Checks if it is safe to assume the new current_state_events
         membership column is up to date
@@ -112,29 +171,31 @@ class RoomMemberWorkerStore(EventsWorkerStore):
 
     @cached(max_entries=100000, iterable=True)
     def get_users_in_room(self, room_id):
-        def f(txn):
-            # If we can assume current_state_events.membership is up to date
-            # then we can avoid a join, which is a Very Good Thing given how
-            # frequently this function gets called.
-            if self._current_state_events_membership_up_to_date:
-                sql = """
-                    SELECT state_key FROM current_state_events
-                    WHERE type = 'm.room.member' AND room_id = ? AND membership = ?
-                """
-            else:
-                sql = """
-                    SELECT state_key FROM room_memberships as m
-                    INNER JOIN current_state_events as c
-                    ON m.event_id = c.event_id
-                    AND m.room_id = c.room_id
-                    AND m.user_id = c.state_key
-                    WHERE c.type = 'm.room.member' AND c.room_id = ? AND m.membership = ?
-                """
+        return self.runInteraction(
+            "get_users_in_room", self.get_users_in_room_txn, room_id
+        )
 
-            txn.execute(sql, (room_id, Membership.JOIN))
-            return [to_ascii(r[0]) for r in txn]
+    def get_users_in_room_txn(self, txn, room_id):
+        # If we can assume current_state_events.membership is up to date
+        # then we can avoid a join, which is a Very Good Thing given how
+        # frequently this function gets called.
+        if self._current_state_events_membership_up_to_date:
+            sql = """
+                SELECT state_key FROM current_state_events
+                WHERE type = 'm.room.member' AND room_id = ? AND membership = ?
+            """
+        else:
+            sql = """
+                SELECT state_key FROM room_memberships as m
+                INNER JOIN current_state_events as c
+                ON m.event_id = c.event_id
+                AND m.room_id = c.room_id
+                AND m.user_id = c.state_key
+                WHERE c.type = 'm.room.member' AND c.room_id = ? AND m.membership = ?
+            """
 
-        return self.runInteraction("get_users_in_room", f)
+        txn.execute(sql, (room_id, Membership.JOIN))
+        return [to_ascii(r[0]) for r in txn]
 
     @cached(max_entries=100000)
     def get_room_summary(self, room_id):
diff --git a/synapse/storage/schema/delta/56/redaction_censor.sql b/synapse/storage/schema/delta/56/redaction_censor.sql
new file mode 100644
index 0000000000..fe51b02309
--- /dev/null
+++ b/synapse/storage/schema/delta/56/redaction_censor.sql
@@ -0,0 +1,17 @@
+/* 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.
+ */
+
+ALTER TABLE redactions ADD COLUMN have_censored BOOL NOT NULL DEFAULT false;
+CREATE INDEX redactions_have_censored ON redactions(event_id) WHERE not have_censored;
diff --git a/synapse/storage/schema/delta/56/stats_separated.sql b/synapse/storage/schema/delta/56/stats_separated.sql
new file mode 100644
index 0000000000..163529c071
--- /dev/null
+++ b/synapse/storage/schema/delta/56/stats_separated.sql
@@ -0,0 +1,152 @@
+/* Copyright 2018 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.
+ */
+
+
+----- First clean up from previous versions of room stats.
+
+-- First remove old stats stuff
+DROP TABLE IF EXISTS room_stats;
+DROP TABLE IF EXISTS room_state;
+DROP TABLE IF EXISTS room_stats_state;
+DROP TABLE IF EXISTS user_stats;
+DROP TABLE IF EXISTS room_stats_earliest_tokens;
+DROP TABLE IF EXISTS _temp_populate_stats_position;
+DROP TABLE IF EXISTS _temp_populate_stats_rooms;
+DROP TABLE IF EXISTS stats_stream_pos;
+
+-- Unschedule old background updates if they're still scheduled
+DELETE FROM background_updates WHERE update_name IN (
+    'populate_stats_createtables',
+    'populate_stats_process_rooms',
+    'populate_stats_process_users',
+    'populate_stats_cleanup'
+);
+
+INSERT INTO background_updates (update_name, progress_json, depends_on) VALUES
+    ('populate_stats_process_rooms', '{}', '');
+
+INSERT INTO background_updates (update_name, progress_json, depends_on) VALUES
+    ('populate_stats_process_users', '{}', 'populate_stats_process_rooms');
+
+----- Create tables for our version of room stats.
+
+-- single-row table to track position of incremental updates
+DROP TABLE IF EXISTS stats_incremental_position;
+CREATE TABLE stats_incremental_position (
+    Lock CHAR(1) NOT NULL DEFAULT 'X' UNIQUE,  -- Makes sure this table only has one row.
+    stream_id  BIGINT NOT NULL,
+    CHECK (Lock='X')
+);
+
+-- insert a null row and make sure it is the only one.
+INSERT INTO stats_incremental_position (
+    stream_id
+) SELECT COALESCE(MAX(stream_ordering), 0) from events;
+
+-- represents PRESENT room statistics for a room
+-- only holds absolute fields
+DROP TABLE IF EXISTS room_stats_current;
+CREATE TABLE room_stats_current (
+    room_id TEXT NOT NULL PRIMARY KEY,
+
+    -- These are absolute counts
+    current_state_events INT NOT NULL,
+    joined_members INT NOT NULL,
+    invited_members INT NOT NULL,
+    left_members INT NOT NULL,
+    banned_members INT NOT NULL,
+
+    local_users_in_room INT NOT NULL,
+
+    -- The maximum delta stream position that this row takes into account.
+    completed_delta_stream_id BIGINT NOT NULL
+);
+
+
+-- represents HISTORICAL room statistics for a room
+DROP TABLE IF EXISTS room_stats_historical;
+CREATE TABLE room_stats_historical (
+    room_id TEXT NOT NULL,
+    -- These stats cover the time from (end_ts - bucket_size)...end_ts (in ms).
+    -- Note that end_ts is quantised.
+    end_ts BIGINT NOT NULL,
+    bucket_size BIGINT NOT NULL,
+
+    -- These stats are absolute counts
+    current_state_events BIGINT NOT NULL,
+    joined_members BIGINT NOT NULL,
+    invited_members BIGINT NOT NULL,
+    left_members BIGINT NOT NULL,
+    banned_members BIGINT NOT NULL,
+    local_users_in_room BIGINT NOT NULL,
+
+    -- These stats are per time slice
+    total_events BIGINT NOT NULL,
+    total_event_bytes BIGINT NOT NULL,
+
+    PRIMARY KEY (room_id, end_ts)
+);
+
+-- We use this index to speed up deletion of ancient room stats.
+CREATE INDEX room_stats_historical_end_ts ON room_stats_historical (end_ts);
+
+-- represents PRESENT statistics for a user
+-- only holds absolute fields
+DROP TABLE IF EXISTS user_stats_current;
+CREATE TABLE user_stats_current (
+    user_id TEXT NOT NULL PRIMARY KEY,
+
+    joined_rooms BIGINT NOT NULL,
+
+    -- The maximum delta stream position that this row takes into account.
+    completed_delta_stream_id BIGINT NOT NULL
+);
+
+-- represents HISTORICAL statistics for a user
+DROP TABLE IF EXISTS user_stats_historical;
+CREATE TABLE user_stats_historical (
+    user_id TEXT NOT NULL,
+    end_ts BIGINT NOT NULL,
+    bucket_size BIGINT NOT NULL,
+
+    joined_rooms BIGINT NOT NULL,
+
+    invites_sent BIGINT NOT NULL,
+    rooms_created BIGINT NOT NULL,
+    total_events BIGINT NOT NULL,
+    total_event_bytes BIGINT NOT NULL,
+
+    PRIMARY KEY (user_id, end_ts)
+);
+
+-- We use this index to speed up deletion of ancient user stats.
+CREATE INDEX user_stats_historical_end_ts ON user_stats_historical (end_ts);
+
+
+CREATE TABLE room_stats_state (
+    room_id TEXT NOT NULL,
+    name TEXT,
+    canonical_alias TEXT,
+    join_rules TEXT,
+    history_visibility TEXT,
+    encryption TEXT,
+    avatar TEXT,
+    guest_access TEXT,
+    is_federatable BOOLEAN,
+    topic TEXT
+);
+
+CREATE UNIQUE INDEX room_stats_state_room ON room_stats_state(room_id);
diff --git a/synapse/storage/stats.py b/synapse/storage/stats.py
index e13efed417..09190d684e 100644
--- a/synapse/storage/stats.py
+++ b/synapse/storage/stats.py
@@ -1,5 +1,6 @@
 # -*- coding: utf-8 -*-
 # 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.
@@ -14,17 +15,22 @@
 # limitations under the License.
 
 import logging
+from itertools import chain
 
 from twisted.internet import defer
+from twisted.internet.defer import DeferredLock
 
 from synapse.api.constants import EventTypes, Membership
-from synapse.storage.prepare_database import get_statements
+from synapse.storage import PostgresEngine
 from synapse.storage.state_deltas import StateDeltasStore
 from synapse.util.caches.descriptors import cached
 
 logger = logging.getLogger(__name__)
 
 # these fields track absolutes (e.g. total number of rooms on the server)
+# You can think of these as Prometheus Gauges.
+# You can draw these stats on a line graph.
+# Example: number of users in a room
 ABSOLUTE_STATS_FIELDS = {
     "room": (
         "current_state_events",
@@ -32,14 +38,23 @@ ABSOLUTE_STATS_FIELDS = {
         "invited_members",
         "left_members",
         "banned_members",
-        "state_events",
+        "local_users_in_room",
     ),
-    "user": ("public_rooms", "private_rooms"),
+    "user": ("joined_rooms",),
 }
 
-TYPE_TO_ROOM = {"room": ("room_stats", "room_id"), "user": ("user_stats", "user_id")}
+# these fields are per-timeslice and so should be reset to 0 upon a new slice
+# You can draw these stats on a histogram.
+# Example: number of events sent locally during a time slice
+PER_SLICE_FIELDS = {
+    "room": ("total_events", "total_event_bytes"),
+    "user": ("invites_sent", "rooms_created", "total_events", "total_event_bytes"),
+}
+
+TYPE_TO_TABLE = {"room": ("room_stats", "room_id"), "user": ("user_stats", "user_id")}
 
-TEMP_TABLE = "_temp_populate_stats"
+# these are the tables (& ID columns) which contain our actual subjects
+TYPE_TO_ORIGIN_TABLE = {"room": ("rooms", "room_id"), "user": ("users", "name")}
 
 
 class StatsStore(StateDeltasStore):
@@ -51,136 +66,102 @@ class StatsStore(StateDeltasStore):
         self.stats_enabled = hs.config.stats_enabled
         self.stats_bucket_size = hs.config.stats_bucket_size
 
-        self.register_background_update_handler(
-            "populate_stats_createtables", self._populate_stats_createtables
-        )
+        self.stats_delta_processing_lock = DeferredLock()
+
         self.register_background_update_handler(
             "populate_stats_process_rooms", self._populate_stats_process_rooms
         )
         self.register_background_update_handler(
-            "populate_stats_cleanup", self._populate_stats_cleanup
+            "populate_stats_process_users", self._populate_stats_process_users
         )
+        # we no longer need to perform clean-up, but we will give ourselves
+        # the potential to reintroduce it in the future ā€“ so documentation
+        # will still encourage the use of this no-op handler.
+        self.register_noop_background_update("populate_stats_cleanup")
+        self.register_noop_background_update("populate_stats_prepare")
 
-    @defer.inlineCallbacks
-    def _populate_stats_createtables(self, progress, batch_size):
-
-        if not self.stats_enabled:
-            yield self._end_background_update("populate_stats_createtables")
-            return 1
-
-        # Get all the rooms that we want to process.
-        def _make_staging_area(txn):
-            # Create the temporary tables
-            stmts = get_statements(
-                """
-                -- We just recreate the table, we'll be reinserting the
-                -- correct entries again later anyway.
-                DROP TABLE IF EXISTS {temp}_rooms;
-
-                CREATE TABLE IF NOT EXISTS {temp}_rooms(
-                    room_id TEXT NOT NULL,
-                    events BIGINT NOT NULL
-                );
-
-                CREATE INDEX {temp}_rooms_events
-                    ON {temp}_rooms(events);
-                CREATE INDEX {temp}_rooms_id
-                    ON {temp}_rooms(room_id);
-            """.format(
-                    temp=TEMP_TABLE
-                ).splitlines()
-            )
-
-            for statement in stmts:
-                txn.execute(statement)
-
-            sql = (
-                "CREATE TABLE IF NOT EXISTS "
-                + TEMP_TABLE
-                + "_position(position TEXT NOT NULL)"
-            )
-            txn.execute(sql)
-
-            # Get rooms we want to process from the database, only adding
-            # those that we haven't (i.e. those not in room_stats_earliest_token)
-            sql = """
-                INSERT INTO %s_rooms (room_id, events)
-                SELECT c.room_id, count(*) FROM current_state_events AS c
-                LEFT JOIN room_stats_earliest_token AS t USING (room_id)
-                WHERE t.room_id IS NULL
-                GROUP BY c.room_id
-            """ % (
-                TEMP_TABLE,
-            )
-            txn.execute(sql)
+    def quantise_stats_time(self, ts):
+        """
+        Quantises a timestamp to be a multiple of the bucket size.
 
-        new_pos = yield self.get_max_stream_id_in_current_state_deltas()
-        yield self.runInteraction("populate_stats_temp_build", _make_staging_area)
-        yield self._simple_insert(TEMP_TABLE + "_position", {"position": new_pos})
-        self.get_earliest_token_for_room_stats.invalidate_all()
+        Args:
+            ts (int): the timestamp to quantise, in milliseconds since the Unix
+                Epoch
 
-        yield self._end_background_update("populate_stats_createtables")
-        return 1
+        Returns:
+            int: a timestamp which
+              - is divisible by the bucket size;
+              - is no later than `ts`; and
+              - is the largest such timestamp.
+        """
+        return (ts // self.stats_bucket_size) * self.stats_bucket_size
 
     @defer.inlineCallbacks
-    def _populate_stats_cleanup(self, progress, batch_size):
+    def _populate_stats_process_users(self, progress, batch_size):
         """
-        Update the user directory stream position, then clean up the old tables.
+        This is a background update which regenerates statistics for users.
         """
         if not self.stats_enabled:
-            yield self._end_background_update("populate_stats_cleanup")
+            yield self._end_background_update("populate_stats_process_users")
             return 1
 
-        position = yield self._simple_select_one_onecol(
-            TEMP_TABLE + "_position", None, "position"
+        last_user_id = progress.get("last_user_id", "")
+
+        def _get_next_batch(txn):
+            sql = """
+                    SELECT DISTINCT name FROM users
+                    WHERE name > ?
+                    ORDER BY name ASC
+                    LIMIT ?
+                """
+            txn.execute(sql, (last_user_id, batch_size))
+            return [r for r, in txn]
+
+        users_to_work_on = yield self.runInteraction(
+            "_populate_stats_process_users", _get_next_batch
         )
-        yield self.update_stats_stream_pos(position)
 
-        def _delete_staging_area(txn):
-            txn.execute("DROP TABLE IF EXISTS " + TEMP_TABLE + "_rooms")
-            txn.execute("DROP TABLE IF EXISTS " + TEMP_TABLE + "_position")
+        # No more rooms -- complete the transaction.
+        if not users_to_work_on:
+            yield self._end_background_update("populate_stats_process_users")
+            return 1
 
-        yield self.runInteraction("populate_stats_cleanup", _delete_staging_area)
+        for user_id in users_to_work_on:
+            yield self._calculate_and_set_initial_state_for_user(user_id)
+            progress["last_user_id"] = user_id
 
-        yield self._end_background_update("populate_stats_cleanup")
-        return 1
+        yield self.runInteraction(
+            "populate_stats_process_users",
+            self._background_update_progress_txn,
+            "populate_stats_process_users",
+            progress,
+        )
+
+        return len(users_to_work_on)
 
     @defer.inlineCallbacks
     def _populate_stats_process_rooms(self, progress, batch_size):
-
+        """
+        This is a background update which regenerates statistics for rooms.
+        """
         if not self.stats_enabled:
             yield self._end_background_update("populate_stats_process_rooms")
             return 1
 
-        # If we don't have progress filed, delete everything.
-        if not progress:
-            yield self.delete_all_stats()
+        last_room_id = progress.get("last_room_id", "")
 
         def _get_next_batch(txn):
-            # Only fetch 250 rooms, so we don't fetch too many at once, even
-            # if those 250 rooms have less than batch_size state events.
             sql = """
-                SELECT room_id, events FROM %s_rooms
-                ORDER BY events DESC
-                LIMIT 250
-            """ % (
-                TEMP_TABLE,
-            )
-            txn.execute(sql)
-            rooms_to_work_on = txn.fetchall()
-
-            if not rooms_to_work_on:
-                return None
-
-            # Get how many are left to process, so we can give status on how
-            # far we are in processing
-            txn.execute("SELECT COUNT(*) FROM " + TEMP_TABLE + "_rooms")
-            progress["remaining"] = txn.fetchone()[0]
-
-            return rooms_to_work_on
+                    SELECT DISTINCT room_id FROM current_state_events
+                    WHERE room_id > ?
+                    ORDER BY room_id ASC
+                    LIMIT ?
+                """
+            txn.execute(sql, (last_room_id, batch_size))
+            return [r for r, in txn]
 
         rooms_to_work_on = yield self.runInteraction(
-            "populate_stats_temp_read", _get_next_batch
+            "populate_stats_rooms_get_batch", _get_next_batch
         )
 
         # No more rooms -- complete the transaction.
@@ -188,154 +169,28 @@ class StatsStore(StateDeltasStore):
             yield self._end_background_update("populate_stats_process_rooms")
             return 1
 
-        logger.info(
-            "Processing the next %d rooms of %d remaining",
-            len(rooms_to_work_on),
-            progress["remaining"],
-        )
-
-        # Number of state events we've processed by going through each room
-        processed_event_count = 0
-
-        for room_id, event_count in rooms_to_work_on:
-
-            current_state_ids = yield self.get_current_state_ids(room_id)
-
-            join_rules_id = current_state_ids.get((EventTypes.JoinRules, ""))
-            history_visibility_id = current_state_ids.get(
-                (EventTypes.RoomHistoryVisibility, "")
-            )
-            encryption_id = current_state_ids.get((EventTypes.RoomEncryption, ""))
-            name_id = current_state_ids.get((EventTypes.Name, ""))
-            topic_id = current_state_ids.get((EventTypes.Topic, ""))
-            avatar_id = current_state_ids.get((EventTypes.RoomAvatar, ""))
-            canonical_alias_id = current_state_ids.get((EventTypes.CanonicalAlias, ""))
-
-            event_ids = [
-                join_rules_id,
-                history_visibility_id,
-                encryption_id,
-                name_id,
-                topic_id,
-                avatar_id,
-                canonical_alias_id,
-            ]
-
-            state_events = yield self.get_events(
-                [ev for ev in event_ids if ev is not None]
-            )
-
-            def _get_or_none(event_id, arg):
-                event = state_events.get(event_id)
-                if event:
-                    return event.content.get(arg)
-                return None
-
-            yield self.update_room_state(
-                room_id,
-                {
-                    "join_rules": _get_or_none(join_rules_id, "join_rule"),
-                    "history_visibility": _get_or_none(
-                        history_visibility_id, "history_visibility"
-                    ),
-                    "encryption": _get_or_none(encryption_id, "algorithm"),
-                    "name": _get_or_none(name_id, "name"),
-                    "topic": _get_or_none(topic_id, "topic"),
-                    "avatar": _get_or_none(avatar_id, "url"),
-                    "canonical_alias": _get_or_none(canonical_alias_id, "alias"),
-                },
-            )
-
-            now = self.hs.get_reactor().seconds()
-
-            # quantise time to the nearest bucket
-            now = (now // self.stats_bucket_size) * self.stats_bucket_size
-
-            def _fetch_data(txn):
-
-                # Get the current token of the room
-                current_token = self._get_max_stream_id_in_current_state_deltas_txn(txn)
-
-                current_state_events = len(current_state_ids)
-
-                membership_counts = self._get_user_counts_in_room_txn(txn, room_id)
-
-                total_state_events = self._get_total_state_event_counts_txn(
-                    txn, room_id
-                )
-
-                self._update_stats_txn(
-                    txn,
-                    "room",
-                    room_id,
-                    now,
-                    {
-                        "bucket_size": self.stats_bucket_size,
-                        "current_state_events": current_state_events,
-                        "joined_members": membership_counts.get(Membership.JOIN, 0),
-                        "invited_members": membership_counts.get(Membership.INVITE, 0),
-                        "left_members": membership_counts.get(Membership.LEAVE, 0),
-                        "banned_members": membership_counts.get(Membership.BAN, 0),
-                        "state_events": total_state_events,
-                    },
-                )
-                self._simple_insert_txn(
-                    txn,
-                    "room_stats_earliest_token",
-                    {"room_id": room_id, "token": current_token},
-                )
-
-                # We've finished a room. Delete it from the table.
-                self._simple_delete_one_txn(
-                    txn, TEMP_TABLE + "_rooms", {"room_id": room_id}
-                )
+        for room_id in rooms_to_work_on:
+            yield self._calculate_and_set_initial_state_for_room(room_id)
+            progress["last_room_id"] = room_id
 
-            yield self.runInteraction("update_room_stats", _fetch_data)
-
-            # Update the remaining counter.
-            progress["remaining"] -= 1
-            yield self.runInteraction(
-                "populate_stats",
-                self._background_update_progress_txn,
-                "populate_stats_process_rooms",
-                progress,
-            )
-
-            processed_event_count += event_count
-
-            if processed_event_count > batch_size:
-                # Don't process any more rooms, we've hit our batch size.
-                return processed_event_count
+        yield self.runInteraction(
+            "_populate_stats_process_rooms",
+            self._background_update_progress_txn,
+            "populate_stats_process_rooms",
+            progress,
+        )
 
-        return processed_event_count
+        return len(rooms_to_work_on)
 
-    def delete_all_stats(self):
+    def get_stats_positions(self):
         """
-        Delete all statistics records.
+        Returns the stats processor positions.
         """
-
-        def _delete_all_stats_txn(txn):
-            txn.execute("DELETE FROM room_state")
-            txn.execute("DELETE FROM room_stats")
-            txn.execute("DELETE FROM room_stats_earliest_token")
-            txn.execute("DELETE FROM user_stats")
-
-        return self.runInteraction("delete_all_stats", _delete_all_stats_txn)
-
-    def get_stats_stream_pos(self):
         return self._simple_select_one_onecol(
-            table="stats_stream_pos",
+            table="stats_incremental_position",
             keyvalues={},
             retcol="stream_id",
-            desc="stats_stream_pos",
-        )
-
-    def update_stats_stream_pos(self, stream_id):
-        return self._simple_update_one(
-            table="stats_stream_pos",
-            keyvalues={},
-            updatevalues={"stream_id": stream_id},
-            desc="update_stats_stream_pos",
+            desc="stats_incremental_position",
         )
 
     def update_room_state(self, room_id, fields):
@@ -361,42 +216,87 @@ class StatsStore(StateDeltasStore):
                 fields[col] = None
 
         return self._simple_upsert(
-            table="room_state",
+            table="room_stats_state",
             keyvalues={"room_id": room_id},
             values=fields,
             desc="update_room_state",
         )
 
-    def get_deltas_for_room(self, room_id, start, size=100):
+    def get_statistics_for_subject(self, stats_type, stats_id, start, size=100):
         """
-        Get statistics deltas for a given room.
+        Get statistics for a given subject.
 
         Args:
-            room_id (str)
+            stats_type (str): The type of subject
+            stats_id (str): The ID of the subject (e.g. room_id or user_id)
             start (int): Pagination start. Number of entries, not timestamp.
             size (int): How many entries to return.
 
         Returns:
             Deferred[list[dict]], where the dict has the keys of
-            ABSOLUTE_STATS_FIELDS["room"] and "ts".
+            ABSOLUTE_STATS_FIELDS[stats_type],  and "bucket_size" and "end_ts".
         """
-        return self._simple_select_list_paginate(
-            "room_stats",
-            {"room_id": room_id},
-            "ts",
+        return self.runInteraction(
+            "get_statistics_for_subject",
+            self._get_statistics_for_subject_txn,
+            stats_type,
+            stats_id,
             start,
             size,
-            retcols=(list(ABSOLUTE_STATS_FIELDS["room"]) + ["ts"]),
+        )
+
+    def _get_statistics_for_subject_txn(
+        self, txn, stats_type, stats_id, start, size=100
+    ):
+        """
+        Transaction-bound version of L{get_statistics_for_subject}.
+        """
+
+        table, id_col = TYPE_TO_TABLE[stats_type]
+        selected_columns = list(
+            ABSOLUTE_STATS_FIELDS[stats_type] + PER_SLICE_FIELDS[stats_type]
+        )
+
+        slice_list = self._simple_select_list_paginate_txn(
+            txn,
+            table + "_historical",
+            {id_col: stats_id},
+            "end_ts",
+            start,
+            size,
+            retcols=selected_columns + ["bucket_size", "end_ts"],
             order_direction="DESC",
         )
 
-    def get_all_room_state(self):
-        return self._simple_select_list(
-            "room_state", None, retcols=("name", "topic", "canonical_alias")
+        return slice_list
+
+    def get_room_stats_state(self, room_id):
+        """
+        Returns the current room_stats_state for a room.
+
+        Args:
+            room_id (str): The ID of the room to return state for.
+
+        Returns (dict):
+            Dictionary containing these keys:
+                "name", "topic", "canonical_alias", "avatar", "join_rules",
+                "history_visibility"
+        """
+        return self._simple_select_one(
+            "room_stats_state",
+            {"room_id": room_id},
+            retcols=(
+                "name",
+                "topic",
+                "canonical_alias",
+                "avatar",
+                "join_rules",
+                "history_visibility",
+            ),
         )
 
     @cached()
-    def get_earliest_token_for_room_stats(self, room_id):
+    def get_earliest_token_for_stats(self, stats_type, id):
         """
         Fetch the "earliest token". This is used by the room stats delta
         processor to ignore deltas that have been processed between the
@@ -406,79 +306,573 @@ class StatsStore(StateDeltasStore):
         Returns:
             Deferred[int]
         """
+        table, id_col = TYPE_TO_TABLE[stats_type]
+
         return self._simple_select_one_onecol(
-            "room_stats_earliest_token",
-            {"room_id": room_id},
-            retcol="token",
+            "%s_current" % (table,),
+            keyvalues={id_col: id},
+            retcol="completed_delta_stream_id",
             allow_none=True,
         )
 
-    def update_stats(self, stats_type, stats_id, ts, fields):
-        table, id_col = TYPE_TO_ROOM[stats_type]
-        return self._simple_upsert(
-            table=table,
-            keyvalues={id_col: stats_id, "ts": ts},
-            values=fields,
-            desc="update_stats",
+    def bulk_update_stats_delta(self, ts, updates, stream_id):
+        """Bulk update stats tables for a given stream_id and updates the stats
+        incremental position.
+
+        Args:
+            ts (int): Current timestamp in ms
+            updates(dict[str, dict[str, dict[str, Counter]]]): The updates to
+                commit as a mapping stats_type -> stats_id -> field -> delta.
+            stream_id (int): Current position.
+
+        Returns:
+            Deferred
+        """
+
+        def _bulk_update_stats_delta_txn(txn):
+            for stats_type, stats_updates in updates.items():
+                for stats_id, fields in stats_updates.items():
+                    self._update_stats_delta_txn(
+                        txn,
+                        ts=ts,
+                        stats_type=stats_type,
+                        stats_id=stats_id,
+                        fields=fields,
+                        complete_with_stream_id=stream_id,
+                    )
+
+            self._simple_update_one_txn(
+                txn,
+                table="stats_incremental_position",
+                keyvalues={},
+                updatevalues={"stream_id": stream_id},
+            )
+
+        return self.runInteraction(
+            "bulk_update_stats_delta", _bulk_update_stats_delta_txn
         )
 
-    def _update_stats_txn(self, txn, stats_type, stats_id, ts, fields):
-        table, id_col = TYPE_TO_ROOM[stats_type]
-        return self._simple_upsert_txn(
-            txn, table=table, keyvalues={id_col: stats_id, "ts": ts}, values=fields
+    def update_stats_delta(
+        self,
+        ts,
+        stats_type,
+        stats_id,
+        fields,
+        complete_with_stream_id,
+        absolute_field_overrides=None,
+    ):
+        """
+        Updates the statistics for a subject, with a delta (difference/relative
+        change).
+
+        Args:
+            ts (int): timestamp of the change
+            stats_type (str): "room" or "user" ā€“ the kind of subject
+            stats_id (str): the subject's ID (room ID or user ID)
+            fields (dict[str, int]): Deltas of stats values.
+            complete_with_stream_id (int, optional):
+                If supplied, converts an incomplete row into a complete row,
+                with the supplied stream_id marked as the stream_id where the
+                row was completed.
+            absolute_field_overrides (dict[str, int]): Current stats values
+                (i.e. not deltas) of absolute fields.
+                Does not work with per-slice fields.
+        """
+
+        return self.runInteraction(
+            "update_stats_delta",
+            self._update_stats_delta_txn,
+            ts,
+            stats_type,
+            stats_id,
+            fields,
+            complete_with_stream_id=complete_with_stream_id,
+            absolute_field_overrides=absolute_field_overrides,
         )
 
-    def update_stats_delta(self, ts, stats_type, stats_id, field, value):
-        def _update_stats_delta(txn):
-            table, id_col = TYPE_TO_ROOM[stats_type]
-
-            sql = (
-                "SELECT * FROM %s"
-                " WHERE %s=? and ts=("
-                "  SELECT MAX(ts) FROM %s"
-                "  WHERE %s=?"
-                ")"
-            ) % (table, id_col, table, id_col)
-            txn.execute(sql, (stats_id, stats_id))
-            rows = self.cursor_to_dict(txn)
-            if len(rows) == 0:
-                # silently skip as we don't have anything to apply a delta to yet.
-                # this tries to minimise any race between the initial sync and
-                # subsequent deltas arriving.
-                return
-
-            current_ts = ts
-            latest_ts = rows[0]["ts"]
-            if current_ts < latest_ts:
-                # This one is in the past, but we're just encountering it now.
-                # Mark it as part of the current bucket.
-                current_ts = latest_ts
-            elif ts != latest_ts:
-                # we have to copy our absolute counters over to the new entry.
-                values = {
-                    key: rows[0][key] for key in ABSOLUTE_STATS_FIELDS[stats_type]
-                }
-                values[id_col] = stats_id
-                values["ts"] = ts
-                values["bucket_size"] = self.stats_bucket_size
-
-                self._simple_insert_txn(txn, table=table, values=values)
-
-            # actually update the new value
-            if stats_type in ABSOLUTE_STATS_FIELDS[stats_type]:
-                self._simple_update_txn(
-                    txn,
-                    table=table,
-                    keyvalues={id_col: stats_id, "ts": current_ts},
-                    updatevalues={field: value},
+    def _update_stats_delta_txn(
+        self,
+        txn,
+        ts,
+        stats_type,
+        stats_id,
+        fields,
+        complete_with_stream_id,
+        absolute_field_overrides=None,
+    ):
+        if absolute_field_overrides is None:
+            absolute_field_overrides = {}
+
+        table, id_col = TYPE_TO_TABLE[stats_type]
+
+        quantised_ts = self.quantise_stats_time(int(ts))
+        end_ts = quantised_ts + self.stats_bucket_size
+
+        # Lets be paranoid and check that all the given field names are known
+        abs_field_names = ABSOLUTE_STATS_FIELDS[stats_type]
+        slice_field_names = PER_SLICE_FIELDS[stats_type]
+        for field in chain(fields.keys(), absolute_field_overrides.keys()):
+            if field not in abs_field_names and field not in slice_field_names:
+                # guard against potential SQL injection dodginess
+                raise ValueError(
+                    "%s is not a recognised field"
+                    " for stats type %s" % (field, stats_type)
                 )
+
+        # Per slice fields do not get added to the _current table
+
+        # This calculates the deltas (`field = field + ?` values)
+        # for absolute fields,
+        # * defaulting to 0 if not specified
+        #     (required for the INSERT part of upserting to work)
+        # * omitting overrides specified in `absolute_field_overrides`
+        deltas_of_absolute_fields = {
+            key: fields.get(key, 0)
+            for key in abs_field_names
+            if key not in absolute_field_overrides
+        }
+
+        # Keep the delta stream ID field up to date
+        absolute_field_overrides = absolute_field_overrides.copy()
+        absolute_field_overrides["completed_delta_stream_id"] = complete_with_stream_id
+
+        # first upsert the `_current` table
+        self._upsert_with_additive_relatives_txn(
+            txn=txn,
+            table=table + "_current",
+            keyvalues={id_col: stats_id},
+            absolutes=absolute_field_overrides,
+            additive_relatives=deltas_of_absolute_fields,
+        )
+
+        per_slice_additive_relatives = {
+            key: fields.get(key, 0) for key in slice_field_names
+        }
+        self._upsert_copy_from_table_with_additive_relatives_txn(
+            txn=txn,
+            into_table=table + "_historical",
+            keyvalues={id_col: stats_id},
+            extra_dst_insvalues={"bucket_size": self.stats_bucket_size},
+            extra_dst_keyvalues={"end_ts": end_ts},
+            additive_relatives=per_slice_additive_relatives,
+            src_table=table + "_current",
+            copy_columns=abs_field_names,
+        )
+
+    def _upsert_with_additive_relatives_txn(
+        self, txn, table, keyvalues, absolutes, additive_relatives
+    ):
+        """Used to update values in the stats tables.
+
+        This is basically a slightly convoluted upsert that *adds* to any
+        existing rows.
+
+        Args:
+            txn
+            table (str): Table name
+            keyvalues (dict[str, any]): Row-identifying key values
+            absolutes (dict[str, any]): Absolute (set) fields
+            additive_relatives (dict[str, int]): Fields that will be added onto
+                if existing row present.
+        """
+        if self.database_engine.can_native_upsert:
+            absolute_updates = [
+                "%(field)s = EXCLUDED.%(field)s" % {"field": field}
+                for field in absolutes.keys()
+            ]
+
+            relative_updates = [
+                "%(field)s = EXCLUDED.%(field)s + %(table)s.%(field)s"
+                % {"table": table, "field": field}
+                for field in additive_relatives.keys()
+            ]
+
+            insert_cols = []
+            qargs = []
+
+            for (key, val) in chain(
+                keyvalues.items(), absolutes.items(), additive_relatives.items()
+            ):
+                insert_cols.append(key)
+                qargs.append(val)
+
+            sql = """
+                INSERT INTO %(table)s (%(insert_cols_cs)s)
+                VALUES (%(insert_vals_qs)s)
+                ON CONFLICT (%(key_columns)s) DO UPDATE SET %(updates)s
+            """ % {
+                "table": table,
+                "insert_cols_cs": ", ".join(insert_cols),
+                "insert_vals_qs": ", ".join(
+                    ["?"] * (len(keyvalues) + len(absolutes) + len(additive_relatives))
+                ),
+                "key_columns": ", ".join(keyvalues),
+                "updates": ", ".join(chain(absolute_updates, relative_updates)),
+            }
+
+            txn.execute(sql, qargs)
+        else:
+            self.database_engine.lock_table(txn, table)
+            retcols = list(chain(absolutes.keys(), additive_relatives.keys()))
+            current_row = self._simple_select_one_txn(
+                txn, table, keyvalues, retcols, allow_none=True
+            )
+            if current_row is None:
+                merged_dict = {**keyvalues, **absolutes, **additive_relatives}
+                self._simple_insert_txn(txn, table, merged_dict)
             else:
-                sql = ("UPDATE %s SET %s=%s+? WHERE %s=? AND ts=?") % (
-                    table,
-                    field,
-                    field,
-                    id_col,
+                for (key, val) in additive_relatives.items():
+                    current_row[key] += val
+                current_row.update(absolutes)
+                self._simple_update_one_txn(txn, table, keyvalues, current_row)
+
+    def _upsert_copy_from_table_with_additive_relatives_txn(
+        self,
+        txn,
+        into_table,
+        keyvalues,
+        extra_dst_keyvalues,
+        extra_dst_insvalues,
+        additive_relatives,
+        src_table,
+        copy_columns,
+    ):
+        """Updates the historic stats table with latest updates.
+
+        This involves copying "absolute" fields from the `_current` table, and
+        adding relative fields to any existing values.
+
+        Args:
+             txn: Transaction
+             into_table (str): The destination table to UPSERT the row into
+             keyvalues (dict[str, any]): Row-identifying key values
+             extra_dst_keyvalues (dict[str, any]): Additional keyvalues
+                for `into_table`.
+             extra_dst_insvalues (dict[str, any]): Additional values to insert
+                on new row creation for `into_table`.
+             additive_relatives (dict[str, any]): Fields that will be added onto
+                if existing row present. (Must be disjoint from copy_columns.)
+             src_table (str): The source table to copy from
+             copy_columns (iterable[str]): The list of columns to copy
+        """
+        if self.database_engine.can_native_upsert:
+            ins_columns = chain(
+                keyvalues,
+                copy_columns,
+                additive_relatives,
+                extra_dst_keyvalues,
+                extra_dst_insvalues,
+            )
+            sel_exprs = chain(
+                keyvalues,
+                copy_columns,
+                (
+                    "?"
+                    for _ in chain(
+                        additive_relatives, extra_dst_keyvalues, extra_dst_insvalues
+                    )
+                ),
+            )
+            keyvalues_where = ("%s = ?" % f for f in keyvalues)
+
+            sets_cc = ("%s = EXCLUDED.%s" % (f, f) for f in copy_columns)
+            sets_ar = (
+                "%s = EXCLUDED.%s + %s.%s" % (f, f, into_table, f)
+                for f in additive_relatives
+            )
+
+            sql = """
+                INSERT INTO %(into_table)s (%(ins_columns)s)
+                SELECT %(sel_exprs)s
+                FROM %(src_table)s
+                WHERE %(keyvalues_where)s
+                ON CONFLICT (%(keyvalues)s)
+                DO UPDATE SET %(sets)s
+            """ % {
+                "into_table": into_table,
+                "ins_columns": ", ".join(ins_columns),
+                "sel_exprs": ", ".join(sel_exprs),
+                "keyvalues_where": " AND ".join(keyvalues_where),
+                "src_table": src_table,
+                "keyvalues": ", ".join(
+                    chain(keyvalues.keys(), extra_dst_keyvalues.keys())
+                ),
+                "sets": ", ".join(chain(sets_cc, sets_ar)),
+            }
+
+            qargs = list(
+                chain(
+                    additive_relatives.values(),
+                    extra_dst_keyvalues.values(),
+                    extra_dst_insvalues.values(),
+                    keyvalues.values(),
                 )
-                txn.execute(sql, (value, stats_id, current_ts))
+            )
+            txn.execute(sql, qargs)
+        else:
+            self.database_engine.lock_table(txn, into_table)
+            src_row = self._simple_select_one_txn(
+                txn, src_table, keyvalues, copy_columns
+            )
+            all_dest_keyvalues = {**keyvalues, **extra_dst_keyvalues}
+            dest_current_row = self._simple_select_one_txn(
+                txn,
+                into_table,
+                keyvalues=all_dest_keyvalues,
+                retcols=list(chain(additive_relatives.keys(), copy_columns)),
+                allow_none=True,
+            )
+
+            if dest_current_row is None:
+                merged_dict = {
+                    **keyvalues,
+                    **extra_dst_keyvalues,
+                    **extra_dst_insvalues,
+                    **src_row,
+                    **additive_relatives,
+                }
+                self._simple_insert_txn(txn, into_table, merged_dict)
+            else:
+                for (key, val) in additive_relatives.items():
+                    src_row[key] = dest_current_row[key] + val
+                self._simple_update_txn(txn, into_table, all_dest_keyvalues, src_row)
+
+    def get_changes_room_total_events_and_bytes(self, min_pos, max_pos):
+        """Fetches the counts of events in the given range of stream IDs.
+
+        Args:
+            min_pos (int)
+            max_pos (int)
+
+        Returns:
+            Deferred[dict[str, dict[str, int]]]: Mapping of room ID to field
+            changes.
+        """
+
+        return self.runInteraction(
+            "stats_incremental_total_events_and_bytes",
+            self.get_changes_room_total_events_and_bytes_txn,
+            min_pos,
+            max_pos,
+        )
 
-        return self.runInteraction("update_stats_delta", _update_stats_delta)
+    def get_changes_room_total_events_and_bytes_txn(self, txn, low_pos, high_pos):
+        """Gets the total_events and total_event_bytes counts for rooms and
+        senders, in a range of stream_orderings (including backfilled events).
+
+        Args:
+            txn
+            low_pos (int): Low stream ordering
+            high_pos (int): High stream ordering
+
+        Returns:
+            tuple[dict[str, dict[str, int]], dict[str, dict[str, int]]]: The
+            room and user deltas for total_events/total_event_bytes in the
+            format of `stats_id` -> fields
+        """
+
+        if low_pos >= high_pos:
+            # nothing to do here.
+            return {}, {}
+
+        if isinstance(self.database_engine, PostgresEngine):
+            new_bytes_expression = "OCTET_LENGTH(json)"
+        else:
+            new_bytes_expression = "LENGTH(CAST(json AS BLOB))"
+
+        sql = """
+            SELECT events.room_id, COUNT(*) AS new_events, SUM(%s) AS new_bytes
+            FROM events INNER JOIN event_json USING (event_id)
+            WHERE (? < stream_ordering AND stream_ordering <= ?)
+                OR (? <= stream_ordering AND stream_ordering <= ?)
+            GROUP BY events.room_id
+        """ % (
+            new_bytes_expression,
+        )
+
+        txn.execute(sql, (low_pos, high_pos, -high_pos, -low_pos))
+
+        room_deltas = {
+            room_id: {"total_events": new_events, "total_event_bytes": new_bytes}
+            for room_id, new_events, new_bytes in txn
+        }
+
+        sql = """
+            SELECT events.sender, COUNT(*) AS new_events, SUM(%s) AS new_bytes
+            FROM events INNER JOIN event_json USING (event_id)
+            WHERE (? < stream_ordering AND stream_ordering <= ?)
+                OR (? <= stream_ordering AND stream_ordering <= ?)
+            GROUP BY events.sender
+        """ % (
+            new_bytes_expression,
+        )
+
+        txn.execute(sql, (low_pos, high_pos, -high_pos, -low_pos))
+
+        user_deltas = {
+            user_id: {"total_events": new_events, "total_event_bytes": new_bytes}
+            for user_id, new_events, new_bytes in txn
+            if self.hs.is_mine_id(user_id)
+        }
+
+        return room_deltas, user_deltas
+
+    @defer.inlineCallbacks
+    def _calculate_and_set_initial_state_for_room(self, room_id):
+        """Calculate and insert an entry into room_stats_current.
+
+        Args:
+            room_id (str)
+
+        Returns:
+            Deferred[tuple[dict, dict, int]]: A tuple of room state, membership
+            counts and stream position.
+        """
+
+        def _fetch_current_state_stats(txn):
+            pos = self.get_room_max_stream_ordering()
+
+            rows = self._simple_select_many_txn(
+                txn,
+                table="current_state_events",
+                column="type",
+                iterable=[
+                    EventTypes.Create,
+                    EventTypes.JoinRules,
+                    EventTypes.RoomHistoryVisibility,
+                    EventTypes.Encryption,
+                    EventTypes.Name,
+                    EventTypes.Topic,
+                    EventTypes.RoomAvatar,
+                    EventTypes.CanonicalAlias,
+                ],
+                keyvalues={"room_id": room_id, "state_key": ""},
+                retcols=["event_id"],
+            )
+
+            event_ids = [row["event_id"] for row in rows]
+
+            txn.execute(
+                """
+                    SELECT membership, count(*) FROM current_state_events
+                    WHERE room_id = ? AND type = 'm.room.member'
+                    GROUP BY membership
+                """,
+                (room_id,),
+            )
+            membership_counts = {membership: cnt for membership, cnt in txn}
+
+            txn.execute(
+                """
+                    SELECT COALESCE(count(*), 0) FROM current_state_events
+                    WHERE room_id = ?
+                """,
+                (room_id,),
+            )
+
+            current_state_events_count, = txn.fetchone()
+
+            users_in_room = self.get_users_in_room_txn(txn, room_id)
+
+            return (
+                event_ids,
+                membership_counts,
+                current_state_events_count,
+                users_in_room,
+                pos,
+            )
+
+        (
+            event_ids,
+            membership_counts,
+            current_state_events_count,
+            users_in_room,
+            pos,
+        ) = yield self.runInteraction(
+            "get_initial_state_for_room", _fetch_current_state_stats
+        )
+
+        state_event_map = yield self.get_events(event_ids, get_prev_content=False)
+
+        room_state = {
+            "join_rules": None,
+            "history_visibility": None,
+            "encryption": None,
+            "name": None,
+            "topic": None,
+            "avatar": None,
+            "canonical_alias": None,
+            "is_federatable": True,
+        }
+
+        for event in state_event_map.values():
+            if event.type == EventTypes.JoinRules:
+                room_state["join_rules"] = event.content.get("join_rule")
+            elif event.type == EventTypes.RoomHistoryVisibility:
+                room_state["history_visibility"] = event.content.get(
+                    "history_visibility"
+                )
+            elif event.type == EventTypes.Encryption:
+                room_state["encryption"] = event.content.get("algorithm")
+            elif event.type == EventTypes.Name:
+                room_state["name"] = event.content.get("name")
+            elif event.type == EventTypes.Topic:
+                room_state["topic"] = event.content.get("topic")
+            elif event.type == EventTypes.RoomAvatar:
+                room_state["avatar"] = event.content.get("url")
+            elif event.type == EventTypes.CanonicalAlias:
+                room_state["canonical_alias"] = event.content.get("alias")
+            elif event.type == EventTypes.Create:
+                room_state["is_federatable"] = (
+                    event.content.get("m.federate", True) is True
+                )
+
+        yield self.update_room_state(room_id, room_state)
+
+        local_users_in_room = [u for u in users_in_room if self.hs.is_mine_id(u)]
+
+        yield self.update_stats_delta(
+            ts=self.clock.time_msec(),
+            stats_type="room",
+            stats_id=room_id,
+            fields={},
+            complete_with_stream_id=pos,
+            absolute_field_overrides={
+                "current_state_events": current_state_events_count,
+                "joined_members": membership_counts.get(Membership.JOIN, 0),
+                "invited_members": membership_counts.get(Membership.INVITE, 0),
+                "left_members": membership_counts.get(Membership.LEAVE, 0),
+                "banned_members": membership_counts.get(Membership.BAN, 0),
+                "local_users_in_room": len(local_users_in_room),
+            },
+        )
+
+    @defer.inlineCallbacks
+    def _calculate_and_set_initial_state_for_user(self, user_id):
+        def _calculate_and_set_initial_state_for_user_txn(txn):
+            pos = self._get_max_stream_id_in_current_state_deltas_txn(txn)
+
+            txn.execute(
+                """
+                SELECT COUNT(distinct room_id) FROM current_state_events
+                    WHERE type = 'm.room.member' AND state_key = ?
+                        AND membership = 'join'
+                """,
+                (user_id,),
+            )
+            count, = txn.fetchone()
+            return count, pos
+
+        joined_rooms, pos = yield self.runInteraction(
+            "calculate_and_set_initial_state_for_user",
+            _calculate_and_set_initial_state_for_user_txn,
+        )
+
+        yield self.update_stats_delta(
+            ts=self.clock.time_msec(),
+            stats_type="user",
+            stats_id=user_id,
+            fields={},
+            complete_with_stream_id=pos,
+            absolute_field_overrides={"joined_rooms": joined_rooms},
+        )
diff --git a/tests/config/test_generate.py b/tests/config/test_generate.py
index 5017cbce85..2684e662de 100644
--- a/tests/config/test_generate.py
+++ b/tests/config/test_generate.py
@@ -17,6 +17,8 @@ import os.path
 import re
 import shutil
 import tempfile
+from contextlib import redirect_stdout
+from io import StringIO
 
 from synapse.config.homeserver import HomeServerConfig
 
@@ -32,17 +34,18 @@ class ConfigGenerationTestCase(unittest.TestCase):
         shutil.rmtree(self.dir)
 
     def test_generate_config_generates_files(self):
-        HomeServerConfig.load_or_generate_config(
-            "",
-            [
-                "--generate-config",
-                "-c",
-                self.file,
-                "--report-stats=yes",
-                "-H",
-                "lemurs.win",
-            ],
-        )
+        with redirect_stdout(StringIO()):
+            HomeServerConfig.load_or_generate_config(
+                "",
+                [
+                    "--generate-config",
+                    "-c",
+                    self.file,
+                    "--report-stats=yes",
+                    "-H",
+                    "lemurs.win",
+                ],
+            )
 
         self.assertSetEqual(
             set(["homeserver.yaml", "lemurs.win.log.config", "lemurs.win.signing.key"]),
diff --git a/tests/config/test_load.py b/tests/config/test_load.py
index 6bfc1970ad..b3e557bd6a 100644
--- a/tests/config/test_load.py
+++ b/tests/config/test_load.py
@@ -15,6 +15,8 @@
 import os.path
 import shutil
 import tempfile
+from contextlib import redirect_stdout
+from io import StringIO
 
 import yaml
 
@@ -26,7 +28,6 @@ from tests import unittest
 class ConfigLoadingTestCase(unittest.TestCase):
     def setUp(self):
         self.dir = tempfile.mkdtemp()
-        print(self.dir)
         self.file = os.path.join(self.dir, "homeserver.yaml")
 
     def tearDown(self):
@@ -94,18 +95,27 @@ class ConfigLoadingTestCase(unittest.TestCase):
         )
         self.assertTrue(config.enable_registration)
 
+    def test_stats_enabled(self):
+        self.generate_config_and_remove_lines_containing("enable_metrics")
+        self.add_lines_to_config(["enable_metrics: true"])
+
+        # The default Metrics Flags are off by default.
+        config = HomeServerConfig.load_config("", ["-c", self.file])
+        self.assertFalse(config.metrics_flags.known_servers)
+
     def generate_config(self):
-        HomeServerConfig.load_or_generate_config(
-            "",
-            [
-                "--generate-config",
-                "-c",
-                self.file,
-                "--report-stats=yes",
-                "-H",
-                "lemurs.win",
-            ],
-        )
+        with redirect_stdout(StringIO()):
+            HomeServerConfig.load_or_generate_config(
+                "",
+                [
+                    "--generate-config",
+                    "-c",
+                    self.file,
+                    "--report-stats=yes",
+                    "-H",
+                    "lemurs.win",
+                ],
+            )
 
     def generate_config_and_remove_lines_containing(self, needle):
         self.generate_config()
diff --git a/tests/handlers/test_register.py b/tests/handlers/test_register.py
index e10296a5e4..1e9ba3a201 100644
--- a/tests/handlers/test_register.py
+++ b/tests/handlers/test_register.py
@@ -171,11 +171,11 @@ class RegistrationTestCase(unittest.HomeserverTestCase):
         rooms = self.get_success(self.store.get_rooms_for_user(user_id))
         self.assertEqual(len(rooms), 0)
 
-    def test_auto_create_auto_join_rooms_when_support_user_exists(self):
+    def test_auto_create_auto_join_rooms_when_user_is_not_a_real_user(self):
         room_alias_str = "#room:test"
         self.hs.config.auto_join_rooms = [room_alias_str]
 
-        self.store.is_support_user = Mock(return_value=True)
+        self.store.is_real_user = Mock(return_value=False)
         user_id = self.get_success(self.handler.register_user(localpart="support"))
         rooms = self.get_success(self.store.get_rooms_for_user(user_id))
         self.assertEqual(len(rooms), 0)
@@ -183,6 +183,31 @@ class RegistrationTestCase(unittest.HomeserverTestCase):
         room_alias = RoomAlias.from_string(room_alias_str)
         self.get_failure(directory_handler.get_association(room_alias), SynapseError)
 
+    def test_auto_create_auto_join_rooms_when_user_is_the_first_real_user(self):
+        room_alias_str = "#room:test"
+        self.hs.config.auto_join_rooms = [room_alias_str]
+
+        self.store.count_real_users = Mock(return_value=1)
+        self.store.is_real_user = Mock(return_value=True)
+        user_id = self.get_success(self.handler.register_user(localpart="real"))
+        rooms = self.get_success(self.store.get_rooms_for_user(user_id))
+        directory_handler = self.hs.get_handlers().directory_handler
+        room_alias = RoomAlias.from_string(room_alias_str)
+        room_id = self.get_success(directory_handler.get_association(room_alias))
+
+        self.assertTrue(room_id["room_id"] in rooms)
+        self.assertEqual(len(rooms), 1)
+
+    def test_auto_create_auto_join_rooms_when_user_is_not_the_first_real_user(self):
+        room_alias_str = "#room:test"
+        self.hs.config.auto_join_rooms = [room_alias_str]
+
+        self.store.count_real_users = Mock(return_value=2)
+        self.store.is_real_user = Mock(return_value=True)
+        user_id = self.get_success(self.handler.register_user(localpart="real"))
+        rooms = self.get_success(self.store.get_rooms_for_user(user_id))
+        self.assertEqual(len(rooms), 0)
+
     def test_auto_create_auto_join_where_no_consent(self):
         """Test to ensure that the first user is not auto-joined to a room if
         they have not given general consent.
diff --git a/tests/handlers/test_stats.py b/tests/handlers/test_stats.py
index a8b858eb4f..7569b6fab5 100644
--- a/tests/handlers/test_stats.py
+++ b/tests/handlers/test_stats.py
@@ -13,16 +13,17 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from mock import Mock
-
-from twisted.internet import defer
-
-from synapse.api.constants import EventTypes, Membership
+from synapse import storage
 from synapse.rest import admin
 from synapse.rest.client.v1 import login, room
 
 from tests import unittest
 
+# The expected number of state events in a fresh public room.
+EXPT_NUM_STATE_EVTS_IN_FRESH_PUBLIC_ROOM = 5
+# The expected number of state events in a fresh private room.
+EXPT_NUM_STATE_EVTS_IN_FRESH_PRIVATE_ROOM = 6
+
 
 class StatsRoomTests(unittest.HomeserverTestCase):
 
@@ -33,7 +34,6 @@ class StatsRoomTests(unittest.HomeserverTestCase):
     ]
 
     def prepare(self, reactor, clock, hs):
-
         self.store = hs.get_datastore()
         self.handler = self.hs.get_stats_handler()
 
@@ -47,7 +47,7 @@ class StatsRoomTests(unittest.HomeserverTestCase):
         self.get_success(
             self.store._simple_insert(
                 "background_updates",
-                {"update_name": "populate_stats_createtables", "progress_json": "{}"},
+                {"update_name": "populate_stats_prepare", "progress_json": "{}"},
             )
         )
         self.get_success(
@@ -56,7 +56,7 @@ class StatsRoomTests(unittest.HomeserverTestCase):
                 {
                     "update_name": "populate_stats_process_rooms",
                     "progress_json": "{}",
-                    "depends_on": "populate_stats_createtables",
+                    "depends_on": "populate_stats_prepare",
                 },
             )
         )
@@ -64,18 +64,58 @@ class StatsRoomTests(unittest.HomeserverTestCase):
             self.store._simple_insert(
                 "background_updates",
                 {
-                    "update_name": "populate_stats_cleanup",
+                    "update_name": "populate_stats_process_users",
                     "progress_json": "{}",
                     "depends_on": "populate_stats_process_rooms",
                 },
             )
         )
+        self.get_success(
+            self.store._simple_insert(
+                "background_updates",
+                {
+                    "update_name": "populate_stats_cleanup",
+                    "progress_json": "{}",
+                    "depends_on": "populate_stats_process_users",
+                },
+            )
+        )
+
+    def get_all_room_state(self):
+        return self.store._simple_select_list(
+            "room_stats_state", None, retcols=("name", "topic", "canonical_alias")
+        )
+
+    def _get_current_stats(self, stats_type, stat_id):
+        table, id_col = storage.stats.TYPE_TO_TABLE[stats_type]
+
+        cols = list(storage.stats.ABSOLUTE_STATS_FIELDS[stats_type]) + list(
+            storage.stats.PER_SLICE_FIELDS[stats_type]
+        )
+
+        end_ts = self.store.quantise_stats_time(self.reactor.seconds() * 1000)
+
+        return self.get_success(
+            self.store._simple_select_one(
+                table + "_historical",
+                {id_col: stat_id, end_ts: end_ts},
+                cols,
+                allow_none=True,
+            )
+        )
+
+    def _perform_background_initial_update(self):
+        # Do the initial population of the stats via the background update
+        self._add_background_updates()
+
+        while not self.get_success(self.store.has_completed_background_updates()):
+            self.get_success(self.store.do_next_background_update(100), by=0.1)
 
     def test_initial_room(self):
         """
         The background updates will build the table from scratch.
         """
-        r = self.get_success(self.store.get_all_room_state())
+        r = self.get_success(self.get_all_room_state())
         self.assertEqual(len(r), 0)
 
         # Disable stats
@@ -91,7 +131,7 @@ class StatsRoomTests(unittest.HomeserverTestCase):
         )
 
         # Stats disabled, shouldn't have done anything
-        r = self.get_success(self.store.get_all_room_state())
+        r = self.get_success(self.get_all_room_state())
         self.assertEqual(len(r), 0)
 
         # Enable stats
@@ -104,7 +144,7 @@ class StatsRoomTests(unittest.HomeserverTestCase):
         while not self.get_success(self.store.has_completed_background_updates()):
             self.get_success(self.store.do_next_background_update(100), by=0.1)
 
-        r = self.get_success(self.store.get_all_room_state())
+        r = self.get_success(self.get_all_room_state())
 
         self.assertEqual(len(r), 1)
         self.assertEqual(r[0]["topic"], "foo")
@@ -114,6 +154,7 @@ class StatsRoomTests(unittest.HomeserverTestCase):
         Ingestion via notify_new_event will ignore tokens that the background
         update have already processed.
         """
+
         self.reactor.advance(86401)
 
         self.hs.config.stats_enabled = False
@@ -138,12 +179,18 @@ class StatsRoomTests(unittest.HomeserverTestCase):
         self.hs.config.stats_enabled = True
         self.handler.stats_enabled = True
         self.store._all_done = False
-        self.get_success(self.store.update_stats_stream_pos(None))
+        self.get_success(
+            self.store._simple_update_one(
+                table="stats_incremental_position",
+                keyvalues={},
+                updatevalues={"stream_id": 0},
+            )
+        )
 
         self.get_success(
             self.store._simple_insert(
                 "background_updates",
-                {"update_name": "populate_stats_createtables", "progress_json": "{}"},
+                {"update_name": "populate_stats_prepare", "progress_json": "{}"},
             )
         )
 
@@ -154,6 +201,8 @@ class StatsRoomTests(unittest.HomeserverTestCase):
         self.helper.invite(room=room_1, src=u1, targ=u2, tok=u1_token)
         self.helper.join(room=room_1, user=u2, tok=u2_token)
 
+        # orig_delta_processor = self.store.
+
         # Now do the initial ingestion.
         self.get_success(
             self.store._simple_insert(
@@ -185,8 +234,15 @@ class StatsRoomTests(unittest.HomeserverTestCase):
         self.helper.invite(room=room_1, src=u1, targ=u3, tok=u1_token)
         self.helper.join(room=room_1, user=u3, tok=u3_token)
 
-        # Get the deltas! There should be two -- day 1, and day 2.
-        r = self.get_success(self.store.get_deltas_for_room(room_1, 0))
+        # self.handler.notify_new_event()
+
+        # We need to let the delta processor advanceā€¦
+        self.pump(10 * 60)
+
+        # Get the slices! There should be two -- day 1, and day 2.
+        r = self.get_success(self.store.get_statistics_for_subject("room", room_1, 0))
+
+        self.assertEqual(len(r), 2)
 
         # The oldest has 2 joined members
         self.assertEqual(r[-1]["joined_members"], 2)
@@ -194,111 +250,476 @@ class StatsRoomTests(unittest.HomeserverTestCase):
         # The newest has 3
         self.assertEqual(r[0]["joined_members"], 3)
 
-    def test_incorrect_state_transition(self):
-        """
-        If the state transition is not one of (JOIN, INVITE, LEAVE, BAN) to
-        (JOIN, INVITE, LEAVE, BAN), an error is raised.
-        """
-        events = {
-            "a1": {"membership": Membership.LEAVE},
-            "a2": {"membership": "not a real thing"},
-        }
-
-        def get_event(event_id, allow_none=True):
-            m = Mock()
-            m.content = events[event_id]
-            d = defer.Deferred()
-            self.reactor.callLater(0.0, d.callback, m)
-            return d
-
-        def get_received_ts(event_id):
-            return defer.succeed(1)
-
-        self.store.get_received_ts = get_received_ts
-        self.store.get_event = get_event
-
-        deltas = [
-            {
-                "type": EventTypes.Member,
-                "state_key": "some_user",
-                "room_id": "room",
-                "event_id": "a1",
-                "prev_event_id": "a2",
-                "stream_id": 60,
-            }
-        ]
-
-        f = self.get_failure(self.handler._handle_deltas(deltas), ValueError)
+    def test_create_user(self):
+        """
+        When we create a user, it should have statistics already ready.
+        """
+
+        u1 = self.register_user("u1", "pass")
+
+        u1stats = self._get_current_stats("user", u1)
+
+        self.assertIsNotNone(u1stats)
+
+        # not in any rooms by default
+        self.assertEqual(u1stats["joined_rooms"], 0)
+
+    def test_create_room(self):
+        """
+        When we create a room, it should have statistics already ready.
+        """
+
+        self._perform_background_initial_update()
+
+        u1 = self.register_user("u1", "pass")
+        u1token = self.login("u1", "pass")
+        r1 = self.helper.create_room_as(u1, tok=u1token)
+        r1stats = self._get_current_stats("room", r1)
+        r2 = self.helper.create_room_as(u1, tok=u1token, is_public=False)
+        r2stats = self._get_current_stats("room", r2)
+
+        self.assertIsNotNone(r1stats)
+        self.assertIsNotNone(r2stats)
+
+        # contains the default things you'd expect in a fresh room
         self.assertEqual(
-            f.value.args[0], "'not a real thing' is not a valid prev_membership"
-        )
-
-        # And the other way...
-        deltas = [
-            {
-                "type": EventTypes.Member,
-                "state_key": "some_user",
-                "room_id": "room",
-                "event_id": "a2",
-                "prev_event_id": "a1",
-                "stream_id": 100,
-            }
-        ]
-
-        f = self.get_failure(self.handler._handle_deltas(deltas), ValueError)
+            r1stats["total_events"],
+            EXPT_NUM_STATE_EVTS_IN_FRESH_PUBLIC_ROOM,
+            "Wrong number of total_events in new room's stats!"
+            " You may need to update this if more state events are added to"
+            " the room creation process.",
+        )
         self.assertEqual(
-            f.value.args[0], "'not a real thing' is not a valid membership"
+            r2stats["total_events"],
+            EXPT_NUM_STATE_EVTS_IN_FRESH_PRIVATE_ROOM,
+            "Wrong number of total_events in new room's stats!"
+            " You may need to update this if more state events are added to"
+            " the room creation process.",
         )
 
-    def test_redacted_prev_event(self):
+        self.assertEqual(
+            r1stats["current_state_events"], EXPT_NUM_STATE_EVTS_IN_FRESH_PUBLIC_ROOM
+        )
+        self.assertEqual(
+            r2stats["current_state_events"], EXPT_NUM_STATE_EVTS_IN_FRESH_PRIVATE_ROOM
+        )
+
+        self.assertEqual(r1stats["joined_members"], 1)
+        self.assertEqual(r1stats["invited_members"], 0)
+        self.assertEqual(r1stats["banned_members"], 0)
+
+        self.assertEqual(r2stats["joined_members"], 1)
+        self.assertEqual(r2stats["invited_members"], 0)
+        self.assertEqual(r2stats["banned_members"], 0)
+
+    def test_send_message_increments_total_events(self):
         """
-        If the prev_event does not exist, then it is assumed to be a LEAVE.
+        When we send a message, it increments total_events.
         """
+
+        self._perform_background_initial_update()
+
         u1 = self.register_user("u1", "pass")
-        u1_token = self.login("u1", "pass")
+        u1token = self.login("u1", "pass")
+        r1 = self.helper.create_room_as(u1, tok=u1token)
+        r1stats_ante = self._get_current_stats("room", r1)
 
-        room_1 = self.helper.create_room_as(u1, tok=u1_token)
+        self.helper.send(r1, "hiss", tok=u1token)
 
-        # Do the initial population of the user directory via the background update
-        self._add_background_updates()
+        r1stats_post = self._get_current_stats("room", r1)
+
+        self.assertEqual(r1stats_post["total_events"] - r1stats_ante["total_events"], 1)
+
+    def test_send_state_event_nonoverwriting(self):
+        """
+        When we send a non-overwriting state event, it increments total_events AND current_state_events
+        """
+
+        self._perform_background_initial_update()
+
+        u1 = self.register_user("u1", "pass")
+        u1token = self.login("u1", "pass")
+        r1 = self.helper.create_room_as(u1, tok=u1token)
+
+        self.helper.send_state(
+            r1, "cat.hissing", {"value": True}, tok=u1token, state_key="tabby"
+        )
+
+        r1stats_ante = self._get_current_stats("room", r1)
+
+        self.helper.send_state(
+            r1, "cat.hissing", {"value": False}, tok=u1token, state_key="moggy"
+        )
+
+        r1stats_post = self._get_current_stats("room", r1)
+
+        self.assertEqual(r1stats_post["total_events"] - r1stats_ante["total_events"], 1)
+        self.assertEqual(
+            r1stats_post["current_state_events"] - r1stats_ante["current_state_events"],
+            1,
+        )
+
+    def test_send_state_event_overwriting(self):
+        """
+        When we send an overwriting state event, it increments total_events ONLY
+        """
+
+        self._perform_background_initial_update()
+
+        u1 = self.register_user("u1", "pass")
+        u1token = self.login("u1", "pass")
+        r1 = self.helper.create_room_as(u1, tok=u1token)
+
+        self.helper.send_state(
+            r1, "cat.hissing", {"value": True}, tok=u1token, state_key="tabby"
+        )
+
+        r1stats_ante = self._get_current_stats("room", r1)
+
+        self.helper.send_state(
+            r1, "cat.hissing", {"value": False}, tok=u1token, state_key="tabby"
+        )
+
+        r1stats_post = self._get_current_stats("room", r1)
+
+        self.assertEqual(r1stats_post["total_events"] - r1stats_ante["total_events"], 1)
+        self.assertEqual(
+            r1stats_post["current_state_events"] - r1stats_ante["current_state_events"],
+            0,
+        )
+
+    def test_join_first_time(self):
+        """
+        When a user joins a room for the first time, total_events, current_state_events and
+        joined_members should increase by exactly 1.
+        """
+
+        self._perform_background_initial_update()
+
+        u1 = self.register_user("u1", "pass")
+        u1token = self.login("u1", "pass")
+        r1 = self.helper.create_room_as(u1, tok=u1token)
+
+        u2 = self.register_user("u2", "pass")
+        u2token = self.login("u2", "pass")
+
+        r1stats_ante = self._get_current_stats("room", r1)
+
+        self.helper.join(r1, u2, tok=u2token)
+
+        r1stats_post = self._get_current_stats("room", r1)
+
+        self.assertEqual(r1stats_post["total_events"] - r1stats_ante["total_events"], 1)
+        self.assertEqual(
+            r1stats_post["current_state_events"] - r1stats_ante["current_state_events"],
+            1,
+        )
+        self.assertEqual(
+            r1stats_post["joined_members"] - r1stats_ante["joined_members"], 1
+        )
+
+    def test_join_after_leave(self):
+        """
+        When a user joins a room after being previously left, total_events and
+        joined_members should increase by exactly 1.
+        current_state_events should not increase.
+        left_members should decrease by exactly 1.
+        """
+
+        self._perform_background_initial_update()
+
+        u1 = self.register_user("u1", "pass")
+        u1token = self.login("u1", "pass")
+        r1 = self.helper.create_room_as(u1, tok=u1token)
+
+        u2 = self.register_user("u2", "pass")
+        u2token = self.login("u2", "pass")
+
+        self.helper.join(r1, u2, tok=u2token)
+        self.helper.leave(r1, u2, tok=u2token)
+
+        r1stats_ante = self._get_current_stats("room", r1)
+
+        self.helper.join(r1, u2, tok=u2token)
+
+        r1stats_post = self._get_current_stats("room", r1)
+
+        self.assertEqual(r1stats_post["total_events"] - r1stats_ante["total_events"], 1)
+        self.assertEqual(
+            r1stats_post["current_state_events"] - r1stats_ante["current_state_events"],
+            0,
+        )
+        self.assertEqual(
+            r1stats_post["joined_members"] - r1stats_ante["joined_members"], +1
+        )
+        self.assertEqual(
+            r1stats_post["left_members"] - r1stats_ante["left_members"], -1
+        )
+
+    def test_invited(self):
+        """
+        When a user invites another user, current_state_events, total_events and
+        invited_members should increase by exactly 1.
+        """
+
+        self._perform_background_initial_update()
+
+        u1 = self.register_user("u1", "pass")
+        u1token = self.login("u1", "pass")
+        r1 = self.helper.create_room_as(u1, tok=u1token)
+
+        u2 = self.register_user("u2", "pass")
+
+        r1stats_ante = self._get_current_stats("room", r1)
+
+        self.helper.invite(r1, u1, u2, tok=u1token)
+
+        r1stats_post = self._get_current_stats("room", r1)
+
+        self.assertEqual(r1stats_post["total_events"] - r1stats_ante["total_events"], 1)
+        self.assertEqual(
+            r1stats_post["current_state_events"] - r1stats_ante["current_state_events"],
+            1,
+        )
+        self.assertEqual(
+            r1stats_post["invited_members"] - r1stats_ante["invited_members"], +1
+        )
+
+    def test_join_after_invite(self):
+        """
+        When a user joins a room after being invited, total_events and
+        joined_members should increase by exactly 1.
+        current_state_events should not increase.
+        invited_members should decrease by exactly 1.
+        """
+
+        self._perform_background_initial_update()
+
+        u1 = self.register_user("u1", "pass")
+        u1token = self.login("u1", "pass")
+        r1 = self.helper.create_room_as(u1, tok=u1token)
+
+        u2 = self.register_user("u2", "pass")
+        u2token = self.login("u2", "pass")
+
+        self.helper.invite(r1, u1, u2, tok=u1token)
+
+        r1stats_ante = self._get_current_stats("room", r1)
+
+        self.helper.join(r1, u2, tok=u2token)
+
+        r1stats_post = self._get_current_stats("room", r1)
+
+        self.assertEqual(r1stats_post["total_events"] - r1stats_ante["total_events"], 1)
+        self.assertEqual(
+            r1stats_post["current_state_events"] - r1stats_ante["current_state_events"],
+            0,
+        )
+        self.assertEqual(
+            r1stats_post["joined_members"] - r1stats_ante["joined_members"], +1
+        )
+        self.assertEqual(
+            r1stats_post["invited_members"] - r1stats_ante["invited_members"], -1
+        )
+
+    def test_left(self):
+        """
+        When a user leaves a room after joining, total_events and
+        left_members should increase by exactly 1.
+        current_state_events should not increase.
+        joined_members should decrease by exactly 1.
+        """
+
+        self._perform_background_initial_update()
+
+        u1 = self.register_user("u1", "pass")
+        u1token = self.login("u1", "pass")
+        r1 = self.helper.create_room_as(u1, tok=u1token)
+
+        u2 = self.register_user("u2", "pass")
+        u2token = self.login("u2", "pass")
+
+        self.helper.join(r1, u2, tok=u2token)
+
+        r1stats_ante = self._get_current_stats("room", r1)
+
+        self.helper.leave(r1, u2, tok=u2token)
+
+        r1stats_post = self._get_current_stats("room", r1)
+
+        self.assertEqual(r1stats_post["total_events"] - r1stats_ante["total_events"], 1)
+        self.assertEqual(
+            r1stats_post["current_state_events"] - r1stats_ante["current_state_events"],
+            0,
+        )
+        self.assertEqual(
+            r1stats_post["left_members"] - r1stats_ante["left_members"], +1
+        )
+        self.assertEqual(
+            r1stats_post["joined_members"] - r1stats_ante["joined_members"], -1
+        )
+
+    def test_banned(self):
+        """
+        When a user is banned from a room after joining, total_events and
+        left_members should increase by exactly 1.
+        current_state_events should not increase.
+        banned_members should decrease by exactly 1.
+        """
+
+        self._perform_background_initial_update()
+
+        u1 = self.register_user("u1", "pass")
+        u1token = self.login("u1", "pass")
+        r1 = self.helper.create_room_as(u1, tok=u1token)
+
+        u2 = self.register_user("u2", "pass")
+        u2token = self.login("u2", "pass")
+
+        self.helper.join(r1, u2, tok=u2token)
+
+        r1stats_ante = self._get_current_stats("room", r1)
+
+        self.helper.change_membership(r1, u1, u2, "ban", tok=u1token)
+
+        r1stats_post = self._get_current_stats("room", r1)
+
+        self.assertEqual(r1stats_post["total_events"] - r1stats_ante["total_events"], 1)
+        self.assertEqual(
+            r1stats_post["current_state_events"] - r1stats_ante["current_state_events"],
+            0,
+        )
+        self.assertEqual(
+            r1stats_post["banned_members"] - r1stats_ante["banned_members"], +1
+        )
+        self.assertEqual(
+            r1stats_post["joined_members"] - r1stats_ante["joined_members"], -1
+        )
+
+    def test_initial_background_update(self):
+        """
+        Test that statistics can be generated by the initial background update
+        handler.
+
+        This test also tests that stats rows are not created for new subjects
+        when stats are disabled. However, it may be desirable to change this
+        behaviour eventually to still keep current rows.
+        """
+
+        self.hs.config.stats_enabled = False
+
+        u1 = self.register_user("u1", "pass")
+        u1token = self.login("u1", "pass")
+        r1 = self.helper.create_room_as(u1, tok=u1token)
+
+        # test that these subjects, which were created during a time of disabled
+        # stats, do not have stats.
+        self.assertIsNone(self._get_current_stats("room", r1))
+        self.assertIsNone(self._get_current_stats("user", u1))
+
+        self.hs.config.stats_enabled = True
+
+        self._perform_background_initial_update()
+
+        r1stats = self._get_current_stats("room", r1)
+        u1stats = self._get_current_stats("user", u1)
+
+        self.assertEqual(r1stats["joined_members"], 1)
+        self.assertEqual(
+            r1stats["current_state_events"], EXPT_NUM_STATE_EVTS_IN_FRESH_PUBLIC_ROOM
+        )
+
+        self.assertEqual(u1stats["joined_rooms"], 1)
+
+    def test_incomplete_stats(self):
+        """
+        This tests that we track incomplete statistics.
+
+        We first test that incomplete stats are incrementally generated,
+        following the preparation of a background regen.
+
+        We then test that these incomplete rows are completed by the background
+        regen.
+        """
+
+        u1 = self.register_user("u1", "pass")
+        u1token = self.login("u1", "pass")
+        u2 = self.register_user("u2", "pass")
+        u2token = self.login("u2", "pass")
+        u3 = self.register_user("u3", "pass")
+        r1 = self.helper.create_room_as(u1, tok=u1token, is_public=False)
+
+        # preparation stage of the initial background update
+        # Ugh, have to reset this flag
+        self.store._all_done = False
+
+        self.get_success(
+            self.store._simple_delete(
+                "room_stats_current", {"1": 1}, "test_delete_stats"
+            )
+        )
+        self.get_success(
+            self.store._simple_delete(
+                "user_stats_current", {"1": 1}, "test_delete_stats"
+            )
+        )
+
+        self.helper.invite(r1, u1, u2, tok=u1token)
+        self.helper.join(r1, u2, tok=u2token)
+        self.helper.invite(r1, u1, u3, tok=u1token)
+        self.helper.send(r1, "thou shalt yield", tok=u1token)
+
+        # now do the background updates
+
+        self.store._all_done = False
+        self.get_success(
+            self.store._simple_insert(
+                "background_updates",
+                {
+                    "update_name": "populate_stats_process_rooms",
+                    "progress_json": "{}",
+                    "depends_on": "populate_stats_prepare",
+                },
+            )
+        )
+        self.get_success(
+            self.store._simple_insert(
+                "background_updates",
+                {
+                    "update_name": "populate_stats_process_users",
+                    "progress_json": "{}",
+                    "depends_on": "populate_stats_process_rooms",
+                },
+            )
+        )
+        self.get_success(
+            self.store._simple_insert(
+                "background_updates",
+                {
+                    "update_name": "populate_stats_cleanup",
+                    "progress_json": "{}",
+                    "depends_on": "populate_stats_process_users",
+                },
+            )
+        )
 
         while not self.get_success(self.store.has_completed_background_updates()):
             self.get_success(self.store.do_next_background_update(100), by=0.1)
 
-        events = {"a1": None, "a2": {"membership": Membership.JOIN}}
-
-        def get_event(event_id, allow_none=True):
-            if events.get(event_id):
-                m = Mock()
-                m.content = events[event_id]
-            else:
-                m = None
-            d = defer.Deferred()
-            self.reactor.callLater(0.0, d.callback, m)
-            return d
-
-        def get_received_ts(event_id):
-            return defer.succeed(1)
-
-        self.store.get_received_ts = get_received_ts
-        self.store.get_event = get_event
-
-        deltas = [
-            {
-                "type": EventTypes.Member,
-                "state_key": "some_user:test",
-                "room_id": room_1,
-                "event_id": "a2",
-                "prev_event_id": "a1",
-                "stream_id": 100,
-            }
-        ]
-
-        # Handle our fake deltas, which has a user going from LEAVE -> JOIN.
-        self.get_success(self.handler._handle_deltas(deltas))
-
-        # One delta, with two joined members -- the room creator, and our fake
-        # user.
-        r = self.get_success(self.store.get_deltas_for_room(room_1, 0))
-        self.assertEqual(len(r), 1)
-        self.assertEqual(r[0]["joined_members"], 2)
+        r1stats_complete = self._get_current_stats("room", r1)
+        u1stats_complete = self._get_current_stats("user", u1)
+        u2stats_complete = self._get_current_stats("user", u2)
+
+        # now we make our assertions
+
+        # check that _complete rows are complete and correct
+        self.assertEqual(r1stats_complete["joined_members"], 2)
+        self.assertEqual(r1stats_complete["invited_members"], 1)
+
+        self.assertEqual(
+            r1stats_complete["current_state_events"],
+            2 + EXPT_NUM_STATE_EVTS_IN_FRESH_PRIVATE_ROOM,
+        )
+
+        self.assertEqual(u1stats_complete["joined_rooms"], 1)
+        self.assertEqual(u2stats_complete["joined_rooms"], 1)
diff --git a/tests/rest/client/v1/utils.py b/tests/rest/client/v1/utils.py
index 9915367144..cdded88b7f 100644
--- a/tests/rest/client/v1/utils.py
+++ b/tests/rest/client/v1/utils.py
@@ -128,8 +128,12 @@ class RestHelper(object):
 
         return channel.json_body
 
-    def send_state(self, room_id, event_type, body, tok, expect_code=200):
-        path = "/_matrix/client/r0/rooms/%s/state/%s" % (room_id, event_type)
+    def send_state(self, room_id, event_type, body, tok, expect_code=200, state_key=""):
+        path = "/_matrix/client/r0/rooms/%s/state/%s/%s" % (
+            room_id,
+            event_type,
+            state_key,
+        )
         if tok:
             path = path + "?access_token=%s" % tok
 
diff --git a/tests/storage/test_redaction.py b/tests/storage/test_redaction.py
index d961b81d48..deecfad9fb 100644
--- a/tests/storage/test_redaction.py
+++ b/tests/storage/test_redaction.py
@@ -17,6 +17,8 @@
 
 from mock import Mock
 
+from canonicaljson import json
+
 from twisted.internet import defer
 
 from synapse.api.constants import EventTypes, Membership
@@ -29,8 +31,10 @@ from tests.utils import create_room
 
 class RedactionTestCase(unittest.HomeserverTestCase):
     def make_homeserver(self, reactor, clock):
+        config = self.default_config()
+        config["redaction_retention_period"] = "30d"
         return self.setup_test_homeserver(
-            resource_for_federation=Mock(), http_client=None
+            resource_for_federation=Mock(), http_client=None, config=config
         )
 
     def prepare(self, reactor, clock, hs):
@@ -286,3 +290,74 @@ class RedactionTestCase(unittest.HomeserverTestCase):
         self.assertEqual(
             fetched.unsigned["redacted_because"].event_id, redaction_event_id2
         )
+
+    def test_redact_censor(self):
+        """Test that a redacted event gets censored in the DB after a month
+        """
+
+        self.get_success(
+            self.inject_room_member(self.room1, self.u_alice, Membership.JOIN)
+        )
+
+        msg_event = self.get_success(self.inject_message(self.room1, self.u_alice, "t"))
+
+        # Check event has not been redacted:
+        event = self.get_success(self.store.get_event(msg_event.event_id))
+
+        self.assertObjectHasAttributes(
+            {
+                "type": EventTypes.Message,
+                "user_id": self.u_alice.to_string(),
+                "content": {"body": "t", "msgtype": "message"},
+            },
+            event,
+        )
+
+        self.assertFalse("redacted_because" in event.unsigned)
+
+        # Redact event
+        reason = "Because I said so"
+        self.get_success(
+            self.inject_redaction(self.room1, msg_event.event_id, self.u_alice, reason)
+        )
+
+        event = self.get_success(self.store.get_event(msg_event.event_id))
+
+        self.assertTrue("redacted_because" in event.unsigned)
+
+        self.assertObjectHasAttributes(
+            {
+                "type": EventTypes.Message,
+                "user_id": self.u_alice.to_string(),
+                "content": {},
+            },
+            event,
+        )
+
+        event_json = self.get_success(
+            self.store._simple_select_one_onecol(
+                table="event_json",
+                keyvalues={"event_id": msg_event.event_id},
+                retcol="json",
+            )
+        )
+
+        self.assert_dict(
+            {"content": {"body": "t", "msgtype": "message"}}, json.loads(event_json)
+        )
+
+        # Advance by 30 days, then advance again to ensure that the looping call
+        # for updating the stream position gets called and then the looping call
+        # for the censoring gets called.
+        self.reactor.advance(60 * 60 * 24 * 31)
+        self.reactor.advance(60 * 60 * 2)
+
+        event_json = self.get_success(
+            self.store._simple_select_one_onecol(
+                table="event_json",
+                keyvalues={"event_id": msg_event.event_id},
+                retcol="json",
+            )
+        )
+
+        self.assert_dict({"content": {}}, json.loads(event_json))
diff --git a/tests/storage/test_roommember.py b/tests/storage/test_roommember.py
index 64cb294c37..447a3c6ffb 100644
--- a/tests/storage/test_roommember.py
+++ b/tests/storage/test_roommember.py
@@ -1,5 +1,6 @@
 # -*- coding: utf-8 -*-
 # Copyright 2014-2016 OpenMarket 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.
@@ -13,78 +14,129 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-
-from mock import Mock
-
-from twisted.internet import defer
+from unittest.mock import Mock
 
 from synapse.api.constants import EventTypes, Membership
 from synapse.api.room_versions import RoomVersions
-from synapse.types import Requester, RoomID, UserID
+from synapse.rest.admin import register_servlets_for_client_rest_resource
+from synapse.rest.client.v1 import login, room
+from synapse.types import Requester, UserID
 
 from tests import unittest
-from tests.utils import create_room, setup_test_homeserver
 
 
-class RoomMemberStoreTestCase(unittest.TestCase):
-    @defer.inlineCallbacks
-    def setUp(self):
-        hs = yield setup_test_homeserver(
-            self.addCleanup, resource_for_federation=Mock(), http_client=None
+class RoomMemberStoreTestCase(unittest.HomeserverTestCase):
+
+    servlets = [
+        login.register_servlets,
+        register_servlets_for_client_rest_resource,
+        room.register_servlets,
+    ]
+
+    def make_homeserver(self, reactor, clock):
+        hs = self.setup_test_homeserver(
+            resource_for_federation=Mock(), http_client=None
         )
+        return hs
+
+    def prepare(self, reactor, clock, hs):
+
         # We can't test the RoomMemberStore on its own without the other event
         # storage logic
         self.store = hs.get_datastore()
         self.event_builder_factory = hs.get_event_builder_factory()
         self.event_creation_handler = hs.get_event_creation_handler()
 
-        self.u_alice = UserID.from_string("@alice:test")
-        self.u_bob = UserID.from_string("@bob:test")
+        self.u_alice = self.register_user("alice", "pass")
+        self.t_alice = self.login("alice", "pass")
+        self.u_bob = self.register_user("bob", "pass")
 
         # User elsewhere on another host
         self.u_charlie = UserID.from_string("@charlie:elsewhere")
 
-        self.room = RoomID.from_string("!abc123:test")
-
-        yield create_room(hs, self.room.to_string(), self.u_alice.to_string())
-
-    @defer.inlineCallbacks
     def inject_room_member(self, room, user, membership, replaces_state=None):
         builder = self.event_builder_factory.for_room_version(
             RoomVersions.V1,
             {
                 "type": EventTypes.Member,
-                "sender": user.to_string(),
-                "state_key": user.to_string(),
-                "room_id": room.to_string(),
+                "sender": user,
+                "state_key": user,
+                "room_id": room,
                 "content": {"membership": membership},
             },
         )
 
-        event, context = yield self.event_creation_handler.create_new_client_event(
-            builder
+        event, context = self.get_success(
+            self.event_creation_handler.create_new_client_event(builder)
         )
 
-        yield self.store.persist_event(event, context)
+        self.get_success(self.store.persist_event(event, context))
 
         return event
 
-    @defer.inlineCallbacks
     def test_one_member(self):
-        yield self.inject_room_member(self.room, self.u_alice, Membership.JOIN)
-
-        self.assertEquals(
-            [self.room.to_string()],
-            [
-                m.room_id
-                for m in (
-                    yield self.store.get_rooms_for_user_where_membership_is(
-                        self.u_alice.to_string(), [Membership.JOIN]
-                    )
-                )
-            ],
+
+        # Alice creates the room, and is automatically joined
+        self.room = self.helper.create_room_as(self.u_alice, tok=self.t_alice)
+
+        rooms_for_user = self.get_success(
+            self.store.get_rooms_for_user_where_membership_is(
+                self.u_alice, [Membership.JOIN]
+            )
         )
 
+        self.assertEquals([self.room], [m.room_id for m in rooms_for_user])
+
+    def test_count_known_servers(self):
+        """
+        _count_known_servers will calculate how many servers are in a room.
+        """
+        self.room = self.helper.create_room_as(self.u_alice, tok=self.t_alice)
+        self.inject_room_member(self.room, self.u_bob, Membership.JOIN)
+        self.inject_room_member(self.room, self.u_charlie.to_string(), Membership.JOIN)
+
+        servers = self.get_success(self.store._count_known_servers())
+        self.assertEqual(servers, 2)
+
+    def test_count_known_servers_stat_counter_disabled(self):
+        """
+        If enabled, the metrics for how many servers are known will be counted.
+        """
+        self.assertTrue("_known_servers_count" not in self.store.__dict__.keys())
+
+        self.room = self.helper.create_room_as(self.u_alice, tok=self.t_alice)
+        self.inject_room_member(self.room, self.u_bob, Membership.JOIN)
+        self.inject_room_member(self.room, self.u_charlie.to_string(), Membership.JOIN)
+
+        self.pump(20)
+
+        self.assertTrue("_known_servers_count" not in self.store.__dict__.keys())
+
+    @unittest.override_config(
+        {"enable_metrics": True, "metrics_flags": {"known_servers": True}}
+    )
+    def test_count_known_servers_stat_counter_enabled(self):
+        """
+        If enabled, the metrics for how many servers are known will be counted.
+        """
+        # Initialises to 1 -- itself
+        self.assertEqual(self.store._known_servers_count, 1)
+
+        self.pump(20)
+
+        # No rooms have been joined, so technically the SQL returns 0, but it
+        # will still say it knows about itself.
+        self.assertEqual(self.store._known_servers_count, 1)
+
+        self.room = self.helper.create_room_as(self.u_alice, tok=self.t_alice)
+        self.inject_room_member(self.room, self.u_bob, Membership.JOIN)
+        self.inject_room_member(self.room, self.u_charlie.to_string(), Membership.JOIN)
+
+        self.pump(20)
+
+        # It now knows about Charlie's server.
+        self.assertEqual(self.store._known_servers_count, 2)
+
 
 class CurrentStateMembershipUpdateTestCase(unittest.HomeserverTestCase):
     def prepare(self, reactor, clock, homeserver):
diff --git a/tests/test_metrics.py b/tests/test_metrics.py
index 2edbae5c6d..270f853d60 100644
--- a/tests/test_metrics.py
+++ b/tests/test_metrics.py
@@ -1,5 +1,6 @@
 # -*- coding: utf-8 -*-
 # Copyright 2018 New Vector Ltd
+# 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.
@@ -13,8 +14,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-
-from synapse.metrics import InFlightGauge
+from synapse.metrics import REGISTRY, InFlightGauge, generate_latest
 
 from tests import unittest
 
@@ -111,3 +111,21 @@ class TestMauLimit(unittest.TestCase):
             }
 
         return results
+
+
+class BuildInfoTests(unittest.TestCase):
+    def test_get_build(self):
+        """
+        The synapse_build_info metric reports the OS version, Python version,
+        and Synapse version.
+        """
+        items = list(
+            filter(
+                lambda x: b"synapse_build_info{" in x,
+                generate_latest(REGISTRY).split(b"\n"),
+            )
+        )
+        self.assertEqual(len(items), 1)
+        self.assertTrue(b"osversion=" in items[0])
+        self.assertTrue(b"pythonversion=" in items[0])
+        self.assertTrue(b"version=" in items[0])