Merge/remove `Slaved*` stores into `WorkerStores` (#14375)

15 files changed, 198 insertions, 374 deletions

diff --git a/synapse/app/admin_cmd.py b/synapse/app/admin_cmd.py
index 3c8c00ea5b..165d1c5db0 100644
--- a/synapse/app/admin_cmd.py
+++ b/synapse/app/admin_cmd.py
@@ -28,10 +28,6 @@ from synapse.config.homeserver import HomeServerConfig
 from synapse.config.logger import setup_logging
 from synapse.events import EventBase
 from synapse.handlers.admin import ExfiltrationWriter
-from synapse.replication.slave.storage.devices import SlavedDeviceStore
-from synapse.replication.slave.storage.events import SlavedEventStore
-from synapse.replication.slave.storage.filtering import SlavedFilteringStore
-from synapse.replication.slave.storage.push_rule import SlavedPushRuleStore
 from synapse.server import HomeServer
 from synapse.storage.database import DatabasePool, LoggingDatabaseConnection
 from synapse.storage.databases.main.account_data import AccountDataWorkerStore
@@ -40,10 +36,24 @@ from synapse.storage.databases.main.appservice import (
     ApplicationServiceWorkerStore,
 )
 from synapse.storage.databases.main.deviceinbox import DeviceInboxWorkerStore
+from synapse.storage.databases.main.devices import DeviceWorkerStore
+from synapse.storage.databases.main.event_federation import EventFederationWorkerStore
+from synapse.storage.databases.main.event_push_actions import (
+    EventPushActionsWorkerStore,
+)
+from synapse.storage.databases.main.events_worker import EventsWorkerStore
+from synapse.storage.databases.main.filtering import FilteringWorkerStore
+from synapse.storage.databases.main.push_rule import PushRulesWorkerStore
 from synapse.storage.databases.main.receipts import ReceiptsWorkerStore
 from synapse.storage.databases.main.registration import RegistrationWorkerStore
+from synapse.storage.databases.main.relations import RelationsWorkerStore
 from synapse.storage.databases.main.room import RoomWorkerStore
+from synapse.storage.databases.main.roommember import RoomMemberWorkerStore
+from synapse.storage.databases.main.signatures import SignatureWorkerStore
+from synapse.storage.databases.main.state import StateGroupWorkerStore
+from synapse.storage.databases.main.stream import StreamWorkerStore
 from synapse.storage.databases.main.tags import TagsWorkerStore
+from synapse.storage.databases.main.user_erasure_store import UserErasureWorkerStore
 from synapse.types import StateMap
 from synapse.util import SYNAPSE_VERSION
 from synapse.util.logcontext import LoggingContext
@@ -52,17 +62,25 @@ logger = logging.getLogger("synapse.app.admin_cmd")
 
 
 class AdminCmdSlavedStore(
-    SlavedFilteringStore,
-    SlavedPushRuleStore,
-    SlavedEventStore,
-    SlavedDeviceStore,
+    FilteringWorkerStore,
+    DeviceWorkerStore,
     TagsWorkerStore,
     DeviceInboxWorkerStore,
     AccountDataWorkerStore,
+    PushRulesWorkerStore,
     ApplicationServiceTransactionWorkerStore,
     ApplicationServiceWorkerStore,
-    RegistrationWorkerStore,
+    RoomMemberWorkerStore,
+    RelationsWorkerStore,
+    EventFederationWorkerStore,
+    EventPushActionsWorkerStore,
+    StateGroupWorkerStore,
+    SignatureWorkerStore,
+    UserErasureWorkerStore,
     ReceiptsWorkerStore,
+    StreamWorkerStore,
+    EventsWorkerStore,
+    RegistrationWorkerStore,
     RoomWorkerStore,
 ):
     def __init__(
diff --git a/synapse/app/generic_worker.py b/synapse/app/generic_worker.py
index cb5892f041..51446b49cd 100644
--- a/synapse/app/generic_worker.py
+++ b/synapse/app/generic_worker.py
@@ -48,12 +48,6 @@ from synapse.http.site import SynapseRequest, SynapseSite
 from synapse.logging.context import LoggingContext
 from synapse.metrics import METRICS_PREFIX, MetricsResource, RegistryProxy
 from synapse.replication.http import REPLICATION_PREFIX, ReplicationRestResource
-from synapse.replication.slave.storage.devices import SlavedDeviceStore
-from synapse.replication.slave.storage.events import SlavedEventStore
-from synapse.replication.slave.storage.filtering import SlavedFilteringStore
-from synapse.replication.slave.storage.keys import SlavedKeyStore
-from synapse.replication.slave.storage.push_rule import SlavedPushRuleStore
-from synapse.replication.slave.storage.pushers import SlavedPusherStore
 from synapse.rest.admin import register_servlets_for_media_repo
 from synapse.rest.client import (
     account_data,
@@ -101,8 +95,16 @@ from synapse.storage.databases.main.appservice import (
 from synapse.storage.databases.main.censor_events import CensorEventsStore
 from synapse.storage.databases.main.client_ips import ClientIpWorkerStore
 from synapse.storage.databases.main.deviceinbox import DeviceInboxWorkerStore
+from synapse.storage.databases.main.devices import DeviceWorkerStore
 from synapse.storage.databases.main.directory import DirectoryWorkerStore
 from synapse.storage.databases.main.e2e_room_keys import EndToEndRoomKeyStore
+from synapse.storage.databases.main.event_federation import EventFederationWorkerStore
+from synapse.storage.databases.main.event_push_actions import (
+    EventPushActionsWorkerStore,
+)
+from synapse.storage.databases.main.events_worker import EventsWorkerStore
+from synapse.storage.databases.main.filtering import FilteringWorkerStore
+from synapse.storage.databases.main.keys import KeyStore
 from synapse.storage.databases.main.lock import LockStore
 from synapse.storage.databases.main.media_repository import MediaRepositoryStore
 from synapse.storage.databases.main.metrics import ServerMetricsStore
@@ -111,17 +113,25 @@ from synapse.storage.databases.main.monthly_active_users import (
 )
 from synapse.storage.databases.main.presence import PresenceStore
 from synapse.storage.databases.main.profile import ProfileWorkerStore
+from synapse.storage.databases.main.push_rule import PushRulesWorkerStore
+from synapse.storage.databases.main.pusher import PusherWorkerStore
 from synapse.storage.databases.main.receipts import ReceiptsWorkerStore
 from synapse.storage.databases.main.registration import RegistrationWorkerStore
+from synapse.storage.databases.main.relations import RelationsWorkerStore
 from synapse.storage.databases.main.room import RoomWorkerStore
 from synapse.storage.databases.main.room_batch import RoomBatchStore
+from synapse.storage.databases.main.roommember import RoomMemberWorkerStore
 from synapse.storage.databases.main.search import SearchStore
 from synapse.storage.databases.main.session import SessionStore
+from synapse.storage.databases.main.signatures import SignatureWorkerStore
+from synapse.storage.databases.main.state import StateGroupWorkerStore
 from synapse.storage.databases.main.stats import StatsStore
+from synapse.storage.databases.main.stream import StreamWorkerStore
 from synapse.storage.databases.main.tags import TagsWorkerStore
 from synapse.storage.databases.main.transactions import TransactionWorkerStore
 from synapse.storage.databases.main.ui_auth import UIAuthWorkerStore
 from synapse.storage.databases.main.user_directory import UserDirectoryStore
+from synapse.storage.databases.main.user_erasure_store import UserErasureWorkerStore
 from synapse.types import JsonDict
 from synapse.util import SYNAPSE_VERSION
 from synapse.util.httpresourcetree import create_resource_tree
@@ -232,26 +242,36 @@ class GenericWorkerSlavedStore(
     EndToEndRoomKeyStore,
     PresenceStore,
     DeviceInboxWorkerStore,
-    SlavedDeviceStore,
-    SlavedPushRuleStore,
+    DeviceWorkerStore,
     TagsWorkerStore,
     AccountDataWorkerStore,
-    SlavedPusherStore,
     CensorEventsStore,
     ClientIpWorkerStore,
-    SlavedEventStore,
-    SlavedKeyStore,
+    # KeyStore isn't really safe to use from a worker, but for now we do so and hope that
+    # the races it creates aren't too bad.
+    KeyStore,
     RoomWorkerStore,
     RoomBatchStore,
     DirectoryWorkerStore,
+    PushRulesWorkerStore,
     ApplicationServiceTransactionWorkerStore,
     ApplicationServiceWorkerStore,
     ProfileWorkerStore,
-    SlavedFilteringStore,
+    FilteringWorkerStore,
     MonthlyActiveUsersWorkerStore,
     MediaRepositoryStore,
     ServerMetricsStore,
+    PusherWorkerStore,
+    RoomMemberWorkerStore,
+    RelationsWorkerStore,
+    EventFederationWorkerStore,
+    EventPushActionsWorkerStore,
+    StateGroupWorkerStore,
+    SignatureWorkerStore,
+    UserErasureWorkerStore,
     ReceiptsWorkerStore,
+    StreamWorkerStore,
+    EventsWorkerStore,
     RegistrationWorkerStore,
     SearchStore,
     TransactionWorkerStore,
diff --git a/synapse/replication/slave/storage/devices.py b/synapse/replication/slave/storage/devices.py
deleted file mode 100644
index 6fcade510a..0000000000
--- a/synapse/replication/slave/storage/devices.py
+++ /dev/null
@@ -1,79 +0,0 @@
-# Copyright 2016 OpenMarket Ltd
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-from typing import TYPE_CHECKING, Any, Iterable
-
-from synapse.replication.slave.storage._slaved_id_tracker import SlavedIdTracker
-from synapse.replication.tcp.streams._base import DeviceListsStream, UserSignatureStream
-from synapse.storage.database import DatabasePool, LoggingDatabaseConnection
-from synapse.storage.databases.main.devices import DeviceWorkerStore
-
-if TYPE_CHECKING:
-    from synapse.server import HomeServer
-
-
-class SlavedDeviceStore(DeviceWorkerStore):
-    def __init__(
-        self,
-        database: DatabasePool,
-        db_conn: LoggingDatabaseConnection,
-        hs: "HomeServer",
-    ):
-        self.hs = hs
-
-        self._device_list_id_gen = SlavedIdTracker(
-            db_conn,
-            "device_lists_stream",
-            "stream_id",
-            extra_tables=[
-                ("user_signature_stream", "stream_id"),
-                ("device_lists_outbound_pokes", "stream_id"),
-                ("device_lists_changes_in_room", "stream_id"),
-            ],
-        )
-
-        super().__init__(database, db_conn, hs)
-
-    def get_device_stream_token(self) -> int:
-        return self._device_list_id_gen.get_current_token()
-
-    def process_replication_rows(
-        self, stream_name: str, instance_name: str, token: int, rows: Iterable[Any]
-    ) -> None:
-        if stream_name == DeviceListsStream.NAME:
-            self._device_list_id_gen.advance(instance_name, token)
-            self._invalidate_caches_for_devices(token, rows)
-        elif stream_name == UserSignatureStream.NAME:
-            self._device_list_id_gen.advance(instance_name, token)
-            for row in rows:
-                self._user_signature_stream_cache.entity_has_changed(row.user_id, token)
-        return super().process_replication_rows(stream_name, instance_name, token, rows)
-
-    def _invalidate_caches_for_devices(
-        self, token: int, rows: Iterable[DeviceListsStream.DeviceListsStreamRow]
-    ) -> None:
-        for row in rows:
-            # The entities are either user IDs (starting with '@') whose devices
-            # have changed, or remote servers that we need to tell about
-            # changes.
-            if row.entity.startswith("@"):
-                self._device_list_stream_cache.entity_has_changed(row.entity, token)
-                self.get_cached_devices_for_user.invalidate((row.entity,))
-                self._get_cached_user_device.invalidate((row.entity,))
-                self.get_device_list_last_stream_id_for_remote.invalidate((row.entity,))
-
-            else:
-                self._device_list_federation_stream_cache.entity_has_changed(
-                    row.entity, token
-                )
diff --git a/synapse/replication/slave/storage/events.py b/synapse/replication/slave/storage/events.py
deleted file mode 100644
index fe47778cb1..0000000000
--- a/synapse/replication/slave/storage/events.py
+++ /dev/null
@@ -1,79 +0,0 @@
-# Copyright 2016 OpenMarket Ltd
-# Copyright 2018 New Vector Ltd
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-import logging
-from typing import TYPE_CHECKING
-
-from synapse.storage.database import DatabasePool, LoggingDatabaseConnection
-from synapse.storage.databases.main.event_federation import EventFederationWorkerStore
-from synapse.storage.databases.main.event_push_actions import (
-    EventPushActionsWorkerStore,
-)
-from synapse.storage.databases.main.events_worker import EventsWorkerStore
-from synapse.storage.databases.main.relations import RelationsWorkerStore
-from synapse.storage.databases.main.roommember import RoomMemberWorkerStore
-from synapse.storage.databases.main.signatures import SignatureWorkerStore
-from synapse.storage.databases.main.state import StateGroupWorkerStore
-from synapse.storage.databases.main.stream import StreamWorkerStore
-from synapse.storage.databases.main.user_erasure_store import UserErasureWorkerStore
-from synapse.util.caches.stream_change_cache import StreamChangeCache
-
-if TYPE_CHECKING:
-    from synapse.server import HomeServer
-
-logger = logging.getLogger(__name__)
-
-
-# So, um, we want to borrow a load of functions intended for reading from
-# a DataStore, but we don't want to take functions that either write to the
-# DataStore or are cached and don't have cache invalidation logic.
-#
-# Rather than write duplicate versions of those functions, or lift them to
-# a common base class, we going to grab the underlying __func__ object from
-# the method descriptor on the DataStore and chuck them into our class.
-
-
-class SlavedEventStore(
-    EventFederationWorkerStore,
-    RoomMemberWorkerStore,
-    EventPushActionsWorkerStore,
-    StreamWorkerStore,
-    StateGroupWorkerStore,
-    SignatureWorkerStore,
-    EventsWorkerStore,
-    UserErasureWorkerStore,
-    RelationsWorkerStore,
-):
-    def __init__(
-        self,
-        database: DatabasePool,
-        db_conn: LoggingDatabaseConnection,
-        hs: "HomeServer",
-    ):
-        super().__init__(database, db_conn, hs)
-
-        events_max = self._stream_id_gen.get_current_token()
-        curr_state_delta_prefill, min_curr_state_delta_id = self.db_pool.get_cache_dict(
-            db_conn,
-            "current_state_delta_stream",
-            entity_column="room_id",
-            stream_column="stream_id",
-            max_value=events_max,  # As we share the stream id with events token
-            limit=1000,
-        )
-        self._curr_state_delta_stream_cache = StreamChangeCache(
-            "_curr_state_delta_stream_cache",
-            min_curr_state_delta_id,
-            prefilled_cache=curr_state_delta_prefill,
-        )
diff --git a/synapse/replication/slave/storage/filtering.py b/synapse/replication/slave/storage/filtering.py
deleted file mode 100644
index c52679cd60..0000000000
--- a/synapse/replication/slave/storage/filtering.py
+++ /dev/null
@@ -1,35 +0,0 @@
-# Copyright 2015, 2016 OpenMarket Ltd
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-from typing import TYPE_CHECKING
-
-from synapse.storage._base import SQLBaseStore
-from synapse.storage.database import DatabasePool, LoggingDatabaseConnection
-from synapse.storage.databases.main.filtering import FilteringStore
-
-if TYPE_CHECKING:
-    from synapse.server import HomeServer
-
-
-class SlavedFilteringStore(SQLBaseStore):
-    def __init__(
-        self,
-        database: DatabasePool,
-        db_conn: LoggingDatabaseConnection,
-        hs: "HomeServer",
-    ):
-        super().__init__(database, db_conn, hs)
-
-    # Filters are immutable so this cache doesn't need to be expired
-    get_user_filter = FilteringStore.__dict__["get_user_filter"]
diff --git a/synapse/replication/slave/storage/keys.py b/synapse/replication/slave/storage/keys.py
deleted file mode 100644
index a00b38c512..0000000000
--- a/synapse/replication/slave/storage/keys.py
+++ /dev/null
@@ -1,20 +0,0 @@
-# Copyright 2015, 2016 OpenMarket Ltd
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-from synapse.storage.databases.main.keys import KeyStore
-
-# KeyStore isn't really safe to use from a worker, but for now we do so and hope that
-# the races it creates aren't too bad.
-
-SlavedKeyStore = KeyStore
diff --git a/synapse/replication/slave/storage/push_rule.py b/synapse/replication/slave/storage/push_rule.py
deleted file mode 100644
index 5e65eaf1e0..0000000000
--- a/synapse/replication/slave/storage/push_rule.py
+++ /dev/null
@@ -1,35 +0,0 @@
-# Copyright 2015, 2016 OpenMarket Ltd
-# Copyright 2018 New Vector Ltd
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-from typing import Any, Iterable
-
-from synapse.replication.tcp.streams import PushRulesStream
-from synapse.storage.databases.main.push_rule import PushRulesWorkerStore
-
-from .events import SlavedEventStore
-
-
-class SlavedPushRuleStore(SlavedEventStore, PushRulesWorkerStore):
-    def get_max_push_rules_stream_id(self) -> int:
-        return self._push_rules_stream_id_gen.get_current_token()
-
-    def process_replication_rows(
-        self, stream_name: str, instance_name: str, token: int, rows: Iterable[Any]
-    ) -> None:
-        if stream_name == PushRulesStream.NAME:
-            self._push_rules_stream_id_gen.advance(instance_name, token)
-            for row in rows:
-                self.get_push_rules_for_user.invalidate((row.user_id,))
-                self.push_rules_stream_cache.entity_has_changed(row.user_id, token)
-        return super().process_replication_rows(stream_name, instance_name, token, rows)
diff --git a/synapse/replication/slave/storage/pushers.py b/synapse/replication/slave/storage/pushers.py
deleted file mode 100644
index 44ed20e424..0000000000
--- a/synapse/replication/slave/storage/pushers.py
+++ /dev/null
@@ -1,47 +0,0 @@
-# Copyright 2016 OpenMarket Ltd
-# Copyright 2018 New Vector Ltd
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-from typing import TYPE_CHECKING, Any, Iterable
-
-from synapse.replication.tcp.streams import PushersStream
-from synapse.storage.database import DatabasePool, LoggingDatabaseConnection
-from synapse.storage.databases.main.pusher import PusherWorkerStore
-
-from ._slaved_id_tracker import SlavedIdTracker
-
-if TYPE_CHECKING:
-    from synapse.server import HomeServer
-
-
-class SlavedPusherStore(PusherWorkerStore):
-    def __init__(
-        self,
-        database: DatabasePool,
-        db_conn: LoggingDatabaseConnection,
-        hs: "HomeServer",
-    ):
-        super().__init__(database, db_conn, hs)
-        self._pushers_id_gen = SlavedIdTracker(  # type: ignore
-            db_conn, "pushers", "id", extra_tables=[("deleted_pushers", "stream_id")]
-        )
-
-    def get_pushers_stream_token(self) -> int:
-        return self._pushers_id_gen.get_current_token()
-
-    def process_replication_rows(
-        self, stream_name: str, instance_name: str, token: int, rows: Iterable[Any]
-    ) -> None:
-        if stream_name == PushersStream.NAME:
-            self._pushers_id_gen.advance(instance_name, token)
-        return super().process_replication_rows(stream_name, instance_name, token, rows)
diff --git a/synapse/storage/databases/main/__init__.py b/synapse/storage/databases/main/__init__.py
index cfaedf5e0c..0e47592be3 100644
--- a/synapse/storage/databases/main/__init__.py
+++ b/synapse/storage/databases/main/__init__.py
@@ -26,9 +26,7 @@ from synapse.storage.database import (
 from synapse.storage.databases.main.stats import UserSortOrder
 from synapse.storage.engines import BaseDatabaseEngine
 from synapse.storage.types import Cursor
-from synapse.storage.util.id_generators import StreamIdGenerator
 from synapse.types import JsonDict, get_domain_from_id
-from synapse.util.caches.stream_change_cache import StreamChangeCache
 
 from .account_data import AccountDataStore
 from .appservice import ApplicationServiceStore, ApplicationServiceTransactionStore
@@ -138,41 +136,8 @@ class DataStore(
         self._clock = hs.get_clock()
         self.database_engine = database.engine
 
-        self._device_list_id_gen = StreamIdGenerator(
-            db_conn,
-            "device_lists_stream",
-            "stream_id",
-            extra_tables=[
-                ("user_signature_stream", "stream_id"),
-                ("device_lists_outbound_pokes", "stream_id"),
-                ("device_lists_changes_in_room", "stream_id"),
-            ],
-        )
-
         super().__init__(database, db_conn, hs)
 
-        events_max = self._stream_id_gen.get_current_token()
-        curr_state_delta_prefill, min_curr_state_delta_id = self.db_pool.get_cache_dict(
-            db_conn,
-            "current_state_delta_stream",
-            entity_column="room_id",
-            stream_column="stream_id",
-            max_value=events_max,  # As we share the stream id with events token
-            limit=1000,
-        )
-        self._curr_state_delta_stream_cache = StreamChangeCache(
-            "_curr_state_delta_stream_cache",
-            min_curr_state_delta_id,
-            prefilled_cache=curr_state_delta_prefill,
-        )
-
-        self._stream_order_on_start = self.get_room_max_stream_ordering()
-        self._min_stream_order_on_start = self.get_room_min_stream_ordering()
-
-    def get_device_stream_token(self) -> int:
-        # TODO: shouldn't this be moved to `DeviceWorkerStore`?
-        return self._device_list_id_gen.get_current_token()
-
     async def get_users(self) -> List[JsonDict]:
         """Function to retrieve a list of users in users table.
 
diff --git a/synapse/storage/databases/main/devices.py b/synapse/storage/databases/main/devices.py
index 979dd4e17e..aa58c2adc3 100644
--- a/synapse/storage/databases/main/devices.py
+++ b/synapse/storage/databases/main/devices.py
@@ -13,7 +13,6 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-import abc
 import logging
 from typing import (
     TYPE_CHECKING,
@@ -39,6 +38,8 @@ from synapse.logging.opentracing import (
     whitelisted_homeserver,
 )
 from synapse.metrics.background_process_metrics import wrap_as_background_process
+from synapse.replication.slave.storage._slaved_id_tracker import SlavedIdTracker
+from synapse.replication.tcp.streams._base import DeviceListsStream, UserSignatureStream
 from synapse.storage._base import SQLBaseStore, db_to_json, make_in_list_sql_clause
 from synapse.storage.database import (
     DatabasePool,
@@ -49,6 +50,11 @@ from synapse.storage.database import (
 from synapse.storage.databases.main.end_to_end_keys import EndToEndKeyWorkerStore
 from synapse.storage.databases.main.roommember import RoomMemberWorkerStore
 from synapse.storage.types import Cursor
+from synapse.storage.util.id_generators import (
+    AbstractStreamIdGenerator,
+    AbstractStreamIdTracker,
+    StreamIdGenerator,
+)
 from synapse.types import JsonDict, get_verify_key_from_cross_signing_key
 from synapse.util import json_decoder, json_encoder
 from synapse.util.caches.descriptors import cached, cachedList
@@ -80,9 +86,32 @@ class DeviceWorkerStore(RoomMemberWorkerStore, EndToEndKeyWorkerStore):
     ):
         super().__init__(database, db_conn, hs)
 
+        if hs.config.worker.worker_app is None:
+            self._device_list_id_gen: AbstractStreamIdTracker = StreamIdGenerator(
+                db_conn,
+                "device_lists_stream",
+                "stream_id",
+                extra_tables=[
+                    ("user_signature_stream", "stream_id"),
+                    ("device_lists_outbound_pokes", "stream_id"),
+                    ("device_lists_changes_in_room", "stream_id"),
+                ],
+            )
+        else:
+            self._device_list_id_gen = SlavedIdTracker(
+                db_conn,
+                "device_lists_stream",
+                "stream_id",
+                extra_tables=[
+                    ("user_signature_stream", "stream_id"),
+                    ("device_lists_outbound_pokes", "stream_id"),
+                    ("device_lists_changes_in_room", "stream_id"),
+                ],
+            )
+
         # Type-ignore: _device_list_id_gen is mixed in from either DataStore (as a
         # StreamIdGenerator) or SlavedDataStore (as a SlavedIdTracker).
-        device_list_max = self._device_list_id_gen.get_current_token()  # type: ignore[attr-defined]
+        device_list_max = self._device_list_id_gen.get_current_token()
         device_list_prefill, min_device_list_id = self.db_pool.get_cache_dict(
             db_conn,
             "device_lists_stream",
@@ -136,6 +165,39 @@ class DeviceWorkerStore(RoomMemberWorkerStore, EndToEndKeyWorkerStore):
                 self._prune_old_outbound_device_pokes, 60 * 60 * 1000
             )
 
+    def process_replication_rows(
+        self, stream_name: str, instance_name: str, token: int, rows: Iterable[Any]
+    ) -> None:
+        if stream_name == DeviceListsStream.NAME:
+            self._device_list_id_gen.advance(instance_name, token)
+            self._invalidate_caches_for_devices(token, rows)
+        elif stream_name == UserSignatureStream.NAME:
+            self._device_list_id_gen.advance(instance_name, token)
+            for row in rows:
+                self._user_signature_stream_cache.entity_has_changed(row.user_id, token)
+        return super().process_replication_rows(stream_name, instance_name, token, rows)
+
+    def _invalidate_caches_for_devices(
+        self, token: int, rows: Iterable[DeviceListsStream.DeviceListsStreamRow]
+    ) -> None:
+        for row in rows:
+            # The entities are either user IDs (starting with '@') whose devices
+            # have changed, or remote servers that we need to tell about
+            # changes.
+            if row.entity.startswith("@"):
+                self._device_list_stream_cache.entity_has_changed(row.entity, token)
+                self.get_cached_devices_for_user.invalidate((row.entity,))
+                self._get_cached_user_device.invalidate((row.entity,))
+                self.get_device_list_last_stream_id_for_remote.invalidate((row.entity,))
+
+            else:
+                self._device_list_federation_stream_cache.entity_has_changed(
+                    row.entity, token
+                )
+
+    def get_device_stream_token(self) -> int:
+        return self._device_list_id_gen.get_current_token()
+
     async def count_devices_by_users(self, user_ids: Optional[List[str]] = None) -> int:
         """Retrieve number of all devices of given users.
         Only returns number of devices that are not marked as hidden.
@@ -677,11 +739,6 @@ class DeviceWorkerStore(RoomMemberWorkerStore, EndToEndKeyWorkerStore):
             },
         )
 
-    @abc.abstractmethod
-    def get_device_stream_token(self) -> int:
-        """Get the current stream id from the _device_list_id_gen"""
-        ...
-
     @trace
     @cancellable
     async def get_user_devices_from_cache(
@@ -1481,6 +1538,10 @@ class DeviceBackgroundUpdateStore(SQLBaseStore):
 
 
 class DeviceStore(DeviceWorkerStore, DeviceBackgroundUpdateStore):
+    # Because we have write access, this will be a StreamIdGenerator
+    # (see DeviceWorkerStore.__init__)
+    _device_list_id_gen: AbstractStreamIdGenerator
+
     def __init__(
         self,
         database: DatabasePool,
@@ -1805,7 +1866,7 @@ class DeviceStore(DeviceWorkerStore, DeviceBackgroundUpdateStore):
                 context,
             )
 
-        async with self._device_list_id_gen.get_next_mult(  # type: ignore[attr-defined]
+        async with self._device_list_id_gen.get_next_mult(
             len(device_ids)
         ) as stream_ids:
             await self.db_pool.runInteraction(
@@ -2044,7 +2105,7 @@ class DeviceStore(DeviceWorkerStore, DeviceBackgroundUpdateStore):
                 [],
             )
 
-        async with self._device_list_id_gen.get_next_mult(len(hosts)) as stream_ids:  # type: ignore[attr-defined]
+        async with self._device_list_id_gen.get_next_mult(len(hosts)) as stream_ids:
             return await self.db_pool.runInteraction(
                 "add_device_list_outbound_pokes",
                 add_device_list_outbound_pokes_txn,
@@ -2058,7 +2119,7 @@ class DeviceStore(DeviceWorkerStore, DeviceBackgroundUpdateStore):
         updates during partial joins.
         """
 
-        async with self._device_list_id_gen.get_next() as stream_id:  # type: ignore[attr-defined]
+        async with self._device_list_id_gen.get_next() as stream_id:
             await self.db_pool.simple_upsert(
                 table="device_lists_remote_pending",
                 keyvalues={
diff --git a/synapse/storage/databases/main/events_worker.py b/synapse/storage/databases/main/events_worker.py
index 69fea452ad..a79091952a 100644
--- a/synapse/storage/databases/main/events_worker.py
+++ b/synapse/storage/databases/main/events_worker.py
@@ -81,6 +81,7 @@ from synapse.util import unwrapFirstError
 from synapse.util.async_helpers import ObservableDeferred, delay_cancellation
 from synapse.util.caches.descriptors import cached, cachedList
 from synapse.util.caches.lrucache import AsyncLruCache
+from synapse.util.caches.stream_change_cache import StreamChangeCache
 from synapse.util.cancellation import cancellable
 from synapse.util.iterutils import batch_iter
 from synapse.util.metrics import Measure
@@ -233,6 +234,21 @@ class EventsWorkerStore(SQLBaseStore):
                     db_conn, "events", "stream_ordering", step=-1
                 )
 
+        events_max = self._stream_id_gen.get_current_token()
+        curr_state_delta_prefill, min_curr_state_delta_id = self.db_pool.get_cache_dict(
+            db_conn,
+            "current_state_delta_stream",
+            entity_column="room_id",
+            stream_column="stream_id",
+            max_value=events_max,  # As we share the stream id with events token
+            limit=1000,
+        )
+        self._curr_state_delta_stream_cache: StreamChangeCache = StreamChangeCache(
+            "_curr_state_delta_stream_cache",
+            min_curr_state_delta_id,
+            prefilled_cache=curr_state_delta_prefill,
+        )
+
         if hs.config.worker.run_background_tasks:
             # We periodically clean out old transaction ID mappings
             self._clock.looping_call(
diff --git a/synapse/storage/databases/main/filtering.py b/synapse/storage/databases/main/filtering.py
index cb9ee08fa8..12f3b601f1 100644
--- a/synapse/storage/databases/main/filtering.py
+++ b/synapse/storage/databases/main/filtering.py
@@ -24,7 +24,7 @@ from synapse.types import JsonDict
 from synapse.util.caches.descriptors import cached
 
 
-class FilteringStore(SQLBaseStore):
+class FilteringWorkerStore(SQLBaseStore):
     @cached(num_args=2)
     async def get_user_filter(
         self, user_localpart: str, filter_id: Union[int, str]
@@ -46,6 +46,8 @@ class FilteringStore(SQLBaseStore):
 
         return db_to_json(def_json)
 
+
+class FilteringStore(FilteringWorkerStore):
     async def add_user_filter(self, user_localpart: str, user_filter: JsonDict) -> int:
         def_json = encode_canonical_json(user_filter)
 
diff --git a/synapse/storage/databases/main/push_rule.py b/synapse/storage/databases/main/push_rule.py
index b6c15f29f8..8ae10f6127 100644
--- a/synapse/storage/databases/main/push_rule.py
+++ b/synapse/storage/databases/main/push_rule.py
@@ -12,13 +12,13 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-import abc
 import logging
 from typing import (
     TYPE_CHECKING,
     Any,
     Collection,
     Dict,
+    Iterable,
     List,
     Mapping,
     Optional,
@@ -31,6 +31,7 @@ from typing import (
 from synapse.api.errors import StoreError
 from synapse.config.homeserver import ExperimentalConfig
 from synapse.replication.slave.storage._slaved_id_tracker import SlavedIdTracker
+from synapse.replication.tcp.streams import PushRulesStream
 from synapse.storage._base import SQLBaseStore
 from synapse.storage.database import (
     DatabasePool,
@@ -90,8 +91,6 @@ def _load_rules(
     return filtered_rules
 
 
-# The ABCMeta metaclass ensures that it cannot be instantiated without
-# the abstract methods being implemented.
 class PushRulesWorkerStore(
     ApplicationServiceWorkerStore,
     PusherWorkerStore,
@@ -99,7 +98,6 @@ class PushRulesWorkerStore(
     ReceiptsWorkerStore,
     EventsWorkerStore,
     SQLBaseStore,
-    metaclass=abc.ABCMeta,
 ):
     """This is an abstract base class where subclasses must implement
     `get_max_push_rules_stream_id` which can be called in the initializer.
@@ -136,14 +134,23 @@ class PushRulesWorkerStore(
             prefilled_cache=push_rules_prefill,
         )
 
-    @abc.abstractmethod
     def get_max_push_rules_stream_id(self) -> int:
         """Get the position of the push rules stream.
 
         Returns:
             int
         """
-        raise NotImplementedError()
+        return self._push_rules_stream_id_gen.get_current_token()
+
+    def process_replication_rows(
+        self, stream_name: str, instance_name: str, token: int, rows: Iterable[Any]
+    ) -> None:
+        if stream_name == PushRulesStream.NAME:
+            self._push_rules_stream_id_gen.advance(instance_name, token)
+            for row in rows:
+                self.get_push_rules_for_user.invalidate((row.user_id,))
+                self.push_rules_stream_cache.entity_has_changed(row.user_id, token)
+        return super().process_replication_rows(stream_name, instance_name, token, rows)
 
     @cached(max_entries=5000)
     async def get_push_rules_for_user(self, user_id: str) -> FilteredPushRules:
diff --git a/synapse/storage/databases/main/pusher.py b/synapse/storage/databases/main/pusher.py
index 01206950a9..4a01562d45 100644
--- a/synapse/storage/databases/main/pusher.py
+++ b/synapse/storage/databases/main/pusher.py
@@ -27,13 +27,19 @@ from typing import (
 )
 
 from synapse.push import PusherConfig, ThrottleParams
+from synapse.replication.slave.storage._slaved_id_tracker import SlavedIdTracker
+from synapse.replication.tcp.streams import PushersStream
 from synapse.storage._base import SQLBaseStore, db_to_json
 from synapse.storage.database import (
     DatabasePool,
     LoggingDatabaseConnection,
     LoggingTransaction,
 )
-from synapse.storage.util.id_generators import StreamIdGenerator
+from synapse.storage.util.id_generators import (
+    AbstractStreamIdGenerator,
+    AbstractStreamIdTracker,
+    StreamIdGenerator,
+)
 from synapse.types import JsonDict
 from synapse.util import json_encoder
 from synapse.util.caches.descriptors import cached
@@ -52,9 +58,21 @@ class PusherWorkerStore(SQLBaseStore):
         hs: "HomeServer",
     ):
         super().__init__(database, db_conn, hs)
-        self._pushers_id_gen = StreamIdGenerator(
-            db_conn, "pushers", "id", extra_tables=[("deleted_pushers", "stream_id")]
-        )
+
+        if hs.config.worker.worker_app is None:
+            self._pushers_id_gen: AbstractStreamIdTracker = StreamIdGenerator(
+                db_conn,
+                "pushers",
+                "id",
+                extra_tables=[("deleted_pushers", "stream_id")],
+            )
+        else:
+            self._pushers_id_gen = SlavedIdTracker(
+                db_conn,
+                "pushers",
+                "id",
+                extra_tables=[("deleted_pushers", "stream_id")],
+            )
 
         self.db_pool.updates.register_background_update_handler(
             "remove_deactivated_pushers",
@@ -96,6 +114,16 @@ class PusherWorkerStore(SQLBaseStore):
 
             yield PusherConfig(**r)
 
+    def get_pushers_stream_token(self) -> int:
+        return self._pushers_id_gen.get_current_token()
+
+    def process_replication_rows(
+        self, stream_name: str, instance_name: str, token: int, rows: Iterable[Any]
+    ) -> None:
+        if stream_name == PushersStream.NAME:
+            self._pushers_id_gen.advance(instance_name, token)
+        return super().process_replication_rows(stream_name, instance_name, token, rows)
+
     async def get_pushers_by_app_id_and_pushkey(
         self, app_id: str, pushkey: str
     ) -> Iterator[PusherConfig]:
@@ -545,8 +573,9 @@ class PusherBackgroundUpdatesStore(SQLBaseStore):
 
 
 class PusherStore(PusherWorkerStore, PusherBackgroundUpdatesStore):
-    def get_pushers_stream_token(self) -> int:
-        return self._pushers_id_gen.get_current_token()
+    # Because we have write access, this will be a StreamIdGenerator
+    # (see PusherWorkerStore.__init__)
+    _pushers_id_gen: AbstractStreamIdGenerator
 
     async def add_pusher(
         self,
diff --git a/synapse/storage/databases/main/stream.py b/synapse/storage/databases/main/stream.py
index 09ce855aa8..cc27ec3804 100644
--- a/synapse/storage/databases/main/stream.py
+++ b/synapse/storage/databases/main/stream.py
@@ -415,6 +415,7 @@ class StreamWorkerStore(EventsWorkerStore, SQLBaseStore):
         )
 
         self._stream_order_on_start = self.get_room_max_stream_ordering()
+        self._min_stream_order_on_start = self.get_room_min_stream_ordering()
 
     def get_room_max_stream_ordering(self) -> int:
         """Get the stream_ordering of regular events that we have committed up to