Merge worker apps into one. (#6964)

1 files changed, 917 insertions, 0 deletions

diff --git a/synapse/app/generic_worker.py b/synapse/app/generic_worker.py
new file mode 100644
index 0000000000..30efd39092
--- /dev/null
+++ b/synapse/app/generic_worker.py
@@ -0,0 +1,917 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+# Copyright 2016 OpenMarket Ltd
+# Copyright 2020 The Matrix.org Foundation C.I.C.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+import contextlib
+import logging
+import sys
+
+from twisted.internet import defer, reactor
+from twisted.web.resource import NoResource
+
+import synapse
+import synapse.events
+from synapse.api.constants import EventTypes
+from synapse.api.errors import HttpResponseException, SynapseError
+from synapse.api.urls import (
+    CLIENT_API_PREFIX,
+    FEDERATION_PREFIX,
+    LEGACY_MEDIA_PREFIX,
+    MEDIA_PREFIX,
+    SERVER_KEY_V2_PREFIX,
+)
+from synapse.app import _base
+from synapse.config._base import ConfigError
+from synapse.config.homeserver import HomeServerConfig
+from synapse.config.logger import setup_logging
+from synapse.federation import send_queue
+from synapse.federation.transport.server import TransportLayerServer
+from synapse.handlers.presence import PresenceHandler, get_interested_parties
+from synapse.http.server import JsonResource
+from synapse.http.servlet import RestServlet, parse_json_object_from_request
+from synapse.http.site import SynapseSite
+from synapse.logging.context import LoggingContext, run_in_background
+from synapse.metrics import METRICS_PREFIX, MetricsResource, RegistryProxy
+from synapse.metrics.background_process_metrics import run_as_background_process
+from synapse.replication.slave.storage._base import BaseSlavedStore, __func__
+from synapse.replication.slave.storage.account_data import SlavedAccountDataStore
+from synapse.replication.slave.storage.appservice import SlavedApplicationServiceStore
+from synapse.replication.slave.storage.client_ips import SlavedClientIpStore
+from synapse.replication.slave.storage.deviceinbox import SlavedDeviceInboxStore
+from synapse.replication.slave.storage.devices import SlavedDeviceStore
+from synapse.replication.slave.storage.directory import DirectoryStore
+from synapse.replication.slave.storage.events import SlavedEventStore
+from synapse.replication.slave.storage.filtering import SlavedFilteringStore
+from synapse.replication.slave.storage.groups import SlavedGroupServerStore
+from synapse.replication.slave.storage.keys import SlavedKeyStore
+from synapse.replication.slave.storage.presence import SlavedPresenceStore
+from synapse.replication.slave.storage.profile import SlavedProfileStore
+from synapse.replication.slave.storage.push_rule import SlavedPushRuleStore
+from synapse.replication.slave.storage.pushers import SlavedPusherStore
+from synapse.replication.slave.storage.receipts import SlavedReceiptsStore
+from synapse.replication.slave.storage.registration import SlavedRegistrationStore
+from synapse.replication.slave.storage.room import RoomStore
+from synapse.replication.slave.storage.transactions import SlavedTransactionStore
+from synapse.replication.tcp.client import ReplicationClientHandler
+from synapse.replication.tcp.streams._base import (
+    DeviceListsStream,
+    ReceiptsStream,
+    ToDeviceStream,
+)
+from synapse.replication.tcp.streams.events import EventsStreamEventRow, EventsStreamRow
+from synapse.rest.admin import register_servlets_for_media_repo
+from synapse.rest.client.v1 import events
+from synapse.rest.client.v1.initial_sync import InitialSyncRestServlet
+from synapse.rest.client.v1.login import LoginRestServlet
+from synapse.rest.client.v1.profile import (
+    ProfileAvatarURLRestServlet,
+    ProfileDisplaynameRestServlet,
+    ProfileRestServlet,
+)
+from synapse.rest.client.v1.push_rule import PushRuleRestServlet
+from synapse.rest.client.v1.room import (
+    JoinedRoomMemberListRestServlet,
+    JoinRoomAliasServlet,
+    PublicRoomListRestServlet,
+    RoomEventContextServlet,
+    RoomInitialSyncRestServlet,
+    RoomMemberListRestServlet,
+    RoomMembershipRestServlet,
+    RoomMessageListRestServlet,
+    RoomSendEventRestServlet,
+    RoomStateEventRestServlet,
+    RoomStateRestServlet,
+)
+from synapse.rest.client.v1.voip import VoipRestServlet
+from synapse.rest.client.v2_alpha import groups, sync, user_directory
+from synapse.rest.client.v2_alpha._base import client_patterns
+from synapse.rest.client.v2_alpha.account import ThreepidRestServlet
+from synapse.rest.client.v2_alpha.keys import KeyChangesServlet, KeyQueryServlet
+from synapse.rest.client.v2_alpha.register import RegisterRestServlet
+from synapse.rest.client.versions import VersionsRestServlet
+from synapse.rest.key.v2 import KeyApiV2Resource
+from synapse.server import HomeServer
+from synapse.storage.data_stores.main.media_repository import MediaRepositoryStore
+from synapse.storage.data_stores.main.monthly_active_users import (
+    MonthlyActiveUsersWorkerStore,
+)
+from synapse.storage.data_stores.main.presence import UserPresenceState
+from synapse.storage.data_stores.main.user_directory import UserDirectoryStore
+from synapse.types import ReadReceipt
+from synapse.util.async_helpers import Linearizer
+from synapse.util.httpresourcetree import create_resource_tree
+from synapse.util.manhole import manhole
+from synapse.util.stringutils import random_string
+from synapse.util.versionstring import get_version_string
+
+logger = logging.getLogger("synapse.app.generic_worker")
+
+
+class PresenceStatusStubServlet(RestServlet):
+    """If presence is disabled this servlet can be used to stub out setting
+    presence status, while proxying the getters to the master instance.
+    """
+
+    PATTERNS = client_patterns("/presence/(?P<user_id>[^/]*)/status")
+
+    def __init__(self, hs):
+        super(PresenceStatusStubServlet, self).__init__()
+        self.http_client = hs.get_simple_http_client()
+        self.auth = hs.get_auth()
+        self.main_uri = hs.config.worker_main_http_uri
+
+    async def on_GET(self, request, user_id):
+        # Pass through the auth headers, if any, in case the access token
+        # is there.
+        auth_headers = request.requestHeaders.getRawHeaders("Authorization", [])
+        headers = {"Authorization": auth_headers}
+
+        try:
+            result = await self.http_client.get_json(
+                self.main_uri + request.uri.decode("ascii"), headers=headers
+            )
+        except HttpResponseException as e:
+            raise e.to_synapse_error()
+
+        return 200, result
+
+    async def on_PUT(self, request, user_id):
+        await self.auth.get_user_by_req(request)
+        return 200, {}
+
+
+class KeyUploadServlet(RestServlet):
+    """An implementation of the `KeyUploadServlet` that responds to read only
+    requests, but otherwise proxies through to the master instance.
+    """
+
+    PATTERNS = client_patterns("/keys/upload(/(?P<device_id>[^/]+))?$")
+
+    def __init__(self, hs):
+        """
+        Args:
+            hs (synapse.server.HomeServer): server
+        """
+        super(KeyUploadServlet, self).__init__()
+        self.auth = hs.get_auth()
+        self.store = hs.get_datastore()
+        self.http_client = hs.get_simple_http_client()
+        self.main_uri = hs.config.worker_main_http_uri
+
+    async def on_POST(self, request, device_id):
+        requester = await self.auth.get_user_by_req(request, allow_guest=True)
+        user_id = requester.user.to_string()
+        body = parse_json_object_from_request(request)
+
+        if device_id is not None:
+            # passing the device_id here is deprecated; however, we allow it
+            # for now for compatibility with older clients.
+            if requester.device_id is not None and device_id != requester.device_id:
+                logger.warning(
+                    "Client uploading keys for a different device "
+                    "(logged in as %s, uploading for %s)",
+                    requester.device_id,
+                    device_id,
+                )
+        else:
+            device_id = requester.device_id
+
+        if device_id is None:
+            raise SynapseError(
+                400, "To upload keys, you must pass device_id when authenticating"
+            )
+
+        if body:
+            # They're actually trying to upload something, proxy to main synapse.
+            # Pass through the auth headers, if any, in case the access token
+            # is there.
+            auth_headers = request.requestHeaders.getRawHeaders(b"Authorization", [])
+            headers = {"Authorization": auth_headers}
+            result = await self.http_client.post_json_get_json(
+                self.main_uri + request.uri.decode("ascii"), body, headers=headers
+            )
+
+            return 200, result
+        else:
+            # Just interested in counts.
+            result = await self.store.count_e2e_one_time_keys(user_id, device_id)
+            return 200, {"one_time_key_counts": result}
+
+
+UPDATE_SYNCING_USERS_MS = 10 * 1000
+
+
+class GenericWorkerPresence(object):
+    def __init__(self, hs):
+        self.hs = hs
+        self.is_mine_id = hs.is_mine_id
+        self.http_client = hs.get_simple_http_client()
+        self.store = hs.get_datastore()
+        self.user_to_num_current_syncs = {}
+        self.clock = hs.get_clock()
+        self.notifier = hs.get_notifier()
+
+        active_presence = self.store.take_presence_startup_info()
+        self.user_to_current_state = {state.user_id: state for state in active_presence}
+
+        # user_id -> last_sync_ms. Lists the users that have stopped syncing
+        # but we haven't notified the master of that yet
+        self.users_going_offline = {}
+
+        self._send_stop_syncing_loop = self.clock.looping_call(
+            self.send_stop_syncing, UPDATE_SYNCING_USERS_MS
+        )
+
+        self.process_id = random_string(16)
+        logger.info("Presence process_id is %r", self.process_id)
+
+    def send_user_sync(self, user_id, is_syncing, last_sync_ms):
+        if self.hs.config.use_presence:
+            self.hs.get_tcp_replication().send_user_sync(
+                user_id, is_syncing, last_sync_ms
+            )
+
+    def mark_as_coming_online(self, user_id):
+        """A user has started syncing. Send a UserSync to the master, unless they
+        had recently stopped syncing.
+
+        Args:
+            user_id (str)
+        """
+        going_offline = self.users_going_offline.pop(user_id, None)
+        if not going_offline:
+            # Safe to skip because we haven't yet told the master they were offline
+            self.send_user_sync(user_id, True, self.clock.time_msec())
+
+    def mark_as_going_offline(self, user_id):
+        """A user has stopped syncing. We wait before notifying the master as
+        its likely they'll come back soon. This allows us to avoid sending
+        a stopped syncing immediately followed by a started syncing notification
+        to the master
+
+        Args:
+            user_id (str)
+        """
+        self.users_going_offline[user_id] = self.clock.time_msec()
+
+    def send_stop_syncing(self):
+        """Check if there are any users who have stopped syncing a while ago
+        and haven't come back yet. If there are poke the master about them.
+        """
+        now = self.clock.time_msec()
+        for user_id, last_sync_ms in list(self.users_going_offline.items()):
+            if now - last_sync_ms > UPDATE_SYNCING_USERS_MS:
+                self.users_going_offline.pop(user_id, None)
+                self.send_user_sync(user_id, False, last_sync_ms)
+
+    def set_state(self, user, state, ignore_status_msg=False):
+        # TODO Hows this supposed to work?
+        return defer.succeed(None)
+
+    get_states = __func__(PresenceHandler.get_states)
+    get_state = __func__(PresenceHandler.get_state)
+    current_state_for_users = __func__(PresenceHandler.current_state_for_users)
+
+    def user_syncing(self, user_id, affect_presence):
+        if affect_presence:
+            curr_sync = self.user_to_num_current_syncs.get(user_id, 0)
+            self.user_to_num_current_syncs[user_id] = curr_sync + 1
+
+            # If we went from no in flight sync to some, notify replication
+            if self.user_to_num_current_syncs[user_id] == 1:
+                self.mark_as_coming_online(user_id)
+
+        def _end():
+            # We check that the user_id is in user_to_num_current_syncs because
+            # user_to_num_current_syncs may have been cleared if we are
+            # shutting down.
+            if affect_presence and user_id in self.user_to_num_current_syncs:
+                self.user_to_num_current_syncs[user_id] -= 1
+
+                # If we went from one in flight sync to non, notify replication
+                if self.user_to_num_current_syncs[user_id] == 0:
+                    self.mark_as_going_offline(user_id)
+
+        @contextlib.contextmanager
+        def _user_syncing():
+            try:
+                yield
+            finally:
+                _end()
+
+        return defer.succeed(_user_syncing())
+
+    @defer.inlineCallbacks
+    def notify_from_replication(self, states, stream_id):
+        parties = yield get_interested_parties(self.store, states)
+        room_ids_to_states, users_to_states = parties
+
+        self.notifier.on_new_event(
+            "presence_key",
+            stream_id,
+            rooms=room_ids_to_states.keys(),
+            users=users_to_states.keys(),
+        )
+
+    @defer.inlineCallbacks
+    def process_replication_rows(self, token, rows):
+        states = [
+            UserPresenceState(
+                row.user_id,
+                row.state,
+                row.last_active_ts,
+                row.last_federation_update_ts,
+                row.last_user_sync_ts,
+                row.status_msg,
+                row.currently_active,
+            )
+            for row in rows
+        ]
+
+        for state in states:
+            self.user_to_current_state[state.user_id] = state
+
+        stream_id = token
+        yield self.notify_from_replication(states, stream_id)
+
+    def get_currently_syncing_users(self):
+        if self.hs.config.use_presence:
+            return [
+                user_id
+                for user_id, count in self.user_to_num_current_syncs.items()
+                if count > 0
+            ]
+        else:
+            return set()
+
+
+class GenericWorkerTyping(object):
+    def __init__(self, hs):
+        self._latest_room_serial = 0
+        self._reset()
+
+    def _reset(self):
+        """
+        Reset the typing handler's data caches.
+        """
+        # map room IDs to serial numbers
+        self._room_serials = {}
+        # map room IDs to sets of users currently typing
+        self._room_typing = {}
+
+    def stream_positions(self):
+        # We must update this typing token from the response of the previous
+        # sync. In particular, the stream id may "reset" back to zero/a low
+        # value which we *must* use for the next replication request.
+        return {"typing": self._latest_room_serial}
+
+    def process_replication_rows(self, token, rows):
+        if self._latest_room_serial > token:
+            # The master has gone backwards. To prevent inconsistent data, just
+            # clear everything.
+            self._reset()
+
+        # Set the latest serial token to whatever the server gave us.
+        self._latest_room_serial = token
+
+        for row in rows:
+            self._room_serials[row.room_id] = token
+            self._room_typing[row.room_id] = row.user_ids
+
+
+class GenericWorkerSlavedStore(
+    # FIXME(#3714): We need to add UserDirectoryStore as we write directly
+    # rather than going via the correct worker.
+    UserDirectoryStore,
+    SlavedDeviceInboxStore,
+    SlavedDeviceStore,
+    SlavedReceiptsStore,
+    SlavedPushRuleStore,
+    SlavedGroupServerStore,
+    SlavedAccountDataStore,
+    SlavedPusherStore,
+    SlavedEventStore,
+    SlavedKeyStore,
+    RoomStore,
+    DirectoryStore,
+    SlavedApplicationServiceStore,
+    SlavedRegistrationStore,
+    SlavedTransactionStore,
+    SlavedProfileStore,
+    SlavedClientIpStore,
+    SlavedPresenceStore,
+    SlavedFilteringStore,
+    MonthlyActiveUsersWorkerStore,
+    MediaRepositoryStore,
+    BaseSlavedStore,
+):
+    def __init__(self, database, db_conn, hs):
+        super(GenericWorkerSlavedStore, self).__init__(database, db_conn, hs)
+
+        # We pull out the current federation stream position now so that we
+        # always have a known value for the federation position in memory so
+        # that we don't have to bounce via a deferred once when we start the
+        # replication streams.
+        self.federation_out_pos_startup = self._get_federation_out_pos(db_conn)
+
+    def _get_federation_out_pos(self, db_conn):
+        sql = "SELECT stream_id FROM federation_stream_position WHERE type = ?"
+        sql = self.database_engine.convert_param_style(sql)
+
+        txn = db_conn.cursor()
+        txn.execute(sql, ("federation",))
+        rows = txn.fetchall()
+        txn.close()
+
+        return rows[0][0] if rows else -1
+
+
+class GenericWorkerServer(HomeServer):
+    DATASTORE_CLASS = GenericWorkerSlavedStore
+
+    def _listen_http(self, listener_config):
+        port = listener_config["port"]
+        bind_addresses = listener_config["bind_addresses"]
+        site_tag = listener_config.get("tag", port)
+        resources = {}
+        for res in listener_config["resources"]:
+            for name in res["names"]:
+                if name == "metrics":
+                    resources[METRICS_PREFIX] = MetricsResource(RegistryProxy)
+                elif name == "client":
+                    resource = JsonResource(self, canonical_json=False)
+
+                    PublicRoomListRestServlet(self).register(resource)
+                    RoomMemberListRestServlet(self).register(resource)
+                    JoinedRoomMemberListRestServlet(self).register(resource)
+                    RoomStateRestServlet(self).register(resource)
+                    RoomEventContextServlet(self).register(resource)
+                    RoomMessageListRestServlet(self).register(resource)
+                    RegisterRestServlet(self).register(resource)
+                    LoginRestServlet(self).register(resource)
+                    ThreepidRestServlet(self).register(resource)
+                    KeyQueryServlet(self).register(resource)
+                    KeyChangesServlet(self).register(resource)
+                    VoipRestServlet(self).register(resource)
+                    PushRuleRestServlet(self).register(resource)
+                    VersionsRestServlet(self).register(resource)
+                    RoomSendEventRestServlet(self).register(resource)
+                    RoomMembershipRestServlet(self).register(resource)
+                    RoomStateEventRestServlet(self).register(resource)
+                    JoinRoomAliasServlet(self).register(resource)
+                    ProfileAvatarURLRestServlet(self).register(resource)
+                    ProfileDisplaynameRestServlet(self).register(resource)
+                    ProfileRestServlet(self).register(resource)
+                    KeyUploadServlet(self).register(resource)
+
+                    sync.register_servlets(self, resource)
+                    events.register_servlets(self, resource)
+                    InitialSyncRestServlet(self).register(resource)
+                    RoomInitialSyncRestServlet(self).register(resource)
+
+                    user_directory.register_servlets(self, resource)
+
+                    # If presence is disabled, use the stub servlet that does
+                    # not allow sending presence
+                    if not self.config.use_presence:
+                        PresenceStatusStubServlet(self).register(resource)
+
+                    groups.register_servlets(self, resource)
+
+                    resources.update({CLIENT_API_PREFIX: resource})
+                elif name == "federation":
+                    resources.update({FEDERATION_PREFIX: TransportLayerServer(self)})
+                elif name == "media":
+                    media_repo = self.get_media_repository_resource()
+
+                    # We need to serve the admin servlets for media on the
+                    # worker.
+                    admin_resource = JsonResource(self, canonical_json=False)
+                    register_servlets_for_media_repo(self, admin_resource)
+
+                    resources.update(
+                        {
+                            MEDIA_PREFIX: media_repo,
+                            LEGACY_MEDIA_PREFIX: media_repo,
+                            "/_synapse/admin": admin_resource,
+                        }
+                    )
+
+                if name == "openid" and "federation" not in res["names"]:
+                    # Only load the openid resource separately if federation resource
+                    # is not specified since federation resource includes openid
+                    # resource.
+                    resources.update(
+                        {
+                            FEDERATION_PREFIX: TransportLayerServer(
+                                self, servlet_groups=["openid"]
+                            )
+                        }
+                    )
+
+                if name in ["keys", "federation"]:
+                    resources[SERVER_KEY_V2_PREFIX] = KeyApiV2Resource(self)
+
+        root_resource = create_resource_tree(resources, NoResource())
+
+        _base.listen_tcp(
+            bind_addresses,
+            port,
+            SynapseSite(
+                "synapse.access.http.%s" % (site_tag,),
+                site_tag,
+                listener_config,
+                root_resource,
+                self.version_string,
+            ),
+            reactor=self.get_reactor(),
+        )
+
+        logger.info("Synapse worker now listening on port %d", port)
+
+    def start_listening(self, listeners):
+        for listener in listeners:
+            if listener["type"] == "http":
+                self._listen_http(listener)
+            elif listener["type"] == "manhole":
+                _base.listen_tcp(
+                    listener["bind_addresses"],
+                    listener["port"],
+                    manhole(
+                        username="matrix", password="rabbithole", globals={"hs": self}
+                    ),
+                )
+            elif listener["type"] == "metrics":
+                if not self.get_config().enable_metrics:
+                    logger.warning(
+                        (
+                            "Metrics listener configured, but "
+                            "enable_metrics is not True!"
+                        )
+                    )
+                else:
+                    _base.listen_metrics(listener["bind_addresses"], listener["port"])
+            else:
+                logger.warning("Unrecognized listener type: %s", listener["type"])
+
+        self.get_tcp_replication().start_replication(self)
+
+    def remove_pusher(self, app_id, push_key, user_id):
+        self.get_tcp_replication().send_remove_pusher(app_id, push_key, user_id)
+
+    def build_tcp_replication(self):
+        return GenericWorkerReplicationHandler(self)
+
+    def build_presence_handler(self):
+        return GenericWorkerPresence(self)
+
+    def build_typing_handler(self):
+        return GenericWorkerTyping(self)
+
+
+class GenericWorkerReplicationHandler(ReplicationClientHandler):
+    def __init__(self, hs):
+        super(GenericWorkerReplicationHandler, self).__init__(hs.get_datastore())
+
+        self.store = hs.get_datastore()
+        self.typing_handler = hs.get_typing_handler()
+        # NB this is a SynchrotronPresence, not a normal PresenceHandler
+        self.presence_handler = hs.get_presence_handler()
+        self.notifier = hs.get_notifier()
+
+        self.notify_pushers = hs.config.start_pushers
+        self.pusher_pool = hs.get_pusherpool()
+
+        if hs.config.send_federation:
+            self.send_handler = FederationSenderHandler(hs, self)
+        else:
+            self.send_handler = None
+
+    async def on_rdata(self, stream_name, token, rows):
+        await super(GenericWorkerReplicationHandler, self).on_rdata(
+            stream_name, token, rows
+        )
+        run_in_background(self.process_and_notify, stream_name, token, rows)
+
+    def get_streams_to_replicate(self):
+        args = super(GenericWorkerReplicationHandler, self).get_streams_to_replicate()
+        args.update(self.typing_handler.stream_positions())
+        if self.send_handler:
+            args.update(self.send_handler.stream_positions())
+        return args
+
+    def get_currently_syncing_users(self):
+        return self.presence_handler.get_currently_syncing_users()
+
+    async def process_and_notify(self, stream_name, token, rows):
+        try:
+            if self.send_handler:
+                self.send_handler.process_replication_rows(stream_name, token, rows)
+
+            if stream_name == "events":
+                # We shouldn't get multiple rows per token for events stream, so
+                # we don't need to optimise this for multiple rows.
+                for row in rows:
+                    if row.type != EventsStreamEventRow.TypeId:
+                        continue
+                    assert isinstance(row, EventsStreamRow)
+
+                    event = await self.store.get_event(
+                        row.data.event_id, allow_rejected=True
+                    )
+                    if event.rejected_reason:
+                        continue
+
+                    extra_users = ()
+                    if event.type == EventTypes.Member:
+                        extra_users = (event.state_key,)
+                    max_token = self.store.get_room_max_stream_ordering()
+                    self.notifier.on_new_room_event(
+                        event, token, max_token, extra_users
+                    )
+
+                await self.pusher_pool.on_new_notifications(token, token)
+            elif stream_name == "push_rules":
+                self.notifier.on_new_event(
+                    "push_rules_key", token, users=[row.user_id for row in rows]
+                )
+            elif stream_name in ("account_data", "tag_account_data"):
+                self.notifier.on_new_event(
+                    "account_data_key", token, users=[row.user_id for row in rows]
+                )
+            elif stream_name == "receipts":
+                self.notifier.on_new_event(
+                    "receipt_key", token, rooms=[row.room_id for row in rows]
+                )
+                await self.pusher_pool.on_new_receipts(
+                    token, token, {row.room_id for row in rows}
+                )
+            elif stream_name == "typing":
+                self.typing_handler.process_replication_rows(token, rows)
+                self.notifier.on_new_event(
+                    "typing_key", token, rooms=[row.room_id for row in rows]
+                )
+            elif stream_name == "to_device":
+                entities = [row.entity for row in rows if row.entity.startswith("@")]
+                if entities:
+                    self.notifier.on_new_event("to_device_key", token, users=entities)
+            elif stream_name == "device_lists":
+                all_room_ids = set()
+                for row in rows:
+                    room_ids = await self.store.get_rooms_for_user(row.user_id)
+                    all_room_ids.update(room_ids)
+                self.notifier.on_new_event("device_list_key", token, rooms=all_room_ids)
+            elif stream_name == "presence":
+                await self.presence_handler.process_replication_rows(token, rows)
+            elif stream_name == "receipts":
+                self.notifier.on_new_event(
+                    "groups_key", token, users=[row.user_id for row in rows]
+                )
+            elif stream_name == "pushers":
+                for row in rows:
+                    if row.deleted:
+                        self.stop_pusher(row.user_id, row.app_id, row.pushkey)
+                    else:
+                        await self.start_pusher(row.user_id, row.app_id, row.pushkey)
+        except Exception:
+            logger.exception("Error processing replication")
+
+    def stop_pusher(self, user_id, app_id, pushkey):
+        if not self.notify_pushers:
+            return
+
+        key = "%s:%s" % (app_id, pushkey)
+        pushers_for_user = self.pusher_pool.pushers.get(user_id, {})
+        pusher = pushers_for_user.pop(key, None)
+        if pusher is None:
+            return
+        logger.info("Stopping pusher %r / %r", user_id, key)
+        pusher.on_stop()
+
+    async def start_pusher(self, user_id, app_id, pushkey):
+        if not self.notify_pushers:
+            return
+
+        key = "%s:%s" % (app_id, pushkey)
+        logger.info("Starting pusher %r / %r", user_id, key)
+        return await self.pusher_pool.start_pusher_by_id(app_id, pushkey, user_id)
+
+    def on_remote_server_up(self, server: str):
+        """Called when get a new REMOTE_SERVER_UP command."""
+
+        # Let's wake up the transaction queue for the server in case we have
+        # pending stuff to send to it.
+        if self.send_handler:
+            self.send_handler.wake_destination(server)
+
+
+class FederationSenderHandler(object):
+    """Processes the replication stream and forwards the appropriate entries
+    to the federation sender.
+    """
+
+    def __init__(self, hs: GenericWorkerServer, replication_client):
+        self.store = hs.get_datastore()
+        self._is_mine_id = hs.is_mine_id
+        self.federation_sender = hs.get_federation_sender()
+        self.replication_client = replication_client
+
+        self.federation_position = self.store.federation_out_pos_startup
+        self._fed_position_linearizer = Linearizer(name="_fed_position_linearizer")
+
+        self._last_ack = self.federation_position
+
+        self._room_serials = {}
+        self._room_typing = {}
+
+    def on_start(self):
+        # There may be some events that are persisted but haven't been sent,
+        # so send them now.
+        self.federation_sender.notify_new_events(
+            self.store.get_room_max_stream_ordering()
+        )
+
+    def wake_destination(self, server: str):
+        self.federation_sender.wake_destination(server)
+
+    def stream_positions(self):
+        return {"federation": self.federation_position}
+
+    def process_replication_rows(self, stream_name, token, rows):
+        # The federation stream contains things that we want to send out, e.g.
+        # presence, typing, etc.
+        if stream_name == "federation":
+            send_queue.process_rows_for_federation(self.federation_sender, rows)
+            run_in_background(self.update_token, token)
+
+        # We also need to poke the federation sender when new events happen
+        elif stream_name == "events":
+            self.federation_sender.notify_new_events(token)
+
+        # ... and when new receipts happen
+        elif stream_name == ReceiptsStream.NAME:
+            run_as_background_process(
+                "process_receipts_for_federation", self._on_new_receipts, rows
+            )
+
+        # ... as well as device updates and messages
+        elif stream_name == DeviceListsStream.NAME:
+            hosts = {row.destination for row in rows}
+            for host in hosts:
+                self.federation_sender.send_device_messages(host)
+
+        elif stream_name == ToDeviceStream.NAME:
+            # The to_device stream includes stuff to be pushed to both local
+            # clients and remote servers, so we ignore entities that start with
+            # '@' (since they'll be local users rather than destinations).
+            hosts = {row.entity for row in rows if not row.entity.startswith("@")}
+            for host in hosts:
+                self.federation_sender.send_device_messages(host)
+
+    async def _on_new_receipts(self, rows):
+        """
+        Args:
+            rows (iterable[synapse.replication.tcp.streams.ReceiptsStreamRow]):
+                new receipts to be processed
+        """
+        for receipt in rows:
+            # we only want to send on receipts for our own users
+            if not self._is_mine_id(receipt.user_id):
+                continue
+            receipt_info = ReadReceipt(
+                receipt.room_id,
+                receipt.receipt_type,
+                receipt.user_id,
+                [receipt.event_id],
+                receipt.data,
+            )
+            await self.federation_sender.send_read_receipt(receipt_info)
+
+    async def update_token(self, token):
+        try:
+            self.federation_position = token
+
+            # We linearize here to ensure we don't have races updating the token
+            with (await self._fed_position_linearizer.queue(None)):
+                if self._last_ack < self.federation_position:
+                    await self.store.update_federation_out_pos(
+                        "federation", self.federation_position
+                    )
+
+                    # We ACK this token over replication so that the master can drop
+                    # its in memory queues
+                    self.replication_client.send_federation_ack(
+                        self.federation_position
+                    )
+                    self._last_ack = self.federation_position
+        except Exception:
+            logger.exception("Error updating federation stream position")
+
+
+def start(config_options):
+    try:
+        config = HomeServerConfig.load_config("Synapse worker", config_options)
+    except ConfigError as e:
+        sys.stderr.write("\n" + str(e) + "\n")
+        sys.exit(1)
+
+    # For backwards compatibility let any of the old app names.
+    assert config.worker_app in (
+        "synapse.app.appservice",
+        "synapse.app.client_reader",
+        "synapse.app.event_creator",
+        "synapse.app.federation_reader",
+        "synapse.app.federation_sender",
+        "synapse.app.frontend_proxy",
+        "synapse.app.generic_worker",
+        "synapse.app.media_repository",
+        "synapse.app.pusher",
+        "synapse.app.synchrotron",
+        "synapse.app.user_dir",
+    )
+
+    if config.worker_app == "synapse.app.appservice":
+        if config.notify_appservices:
+            sys.stderr.write(
+                "\nThe appservices must be disabled in the main synapse process"
+                "\nbefore they can be run in a separate worker."
+                "\nPlease add ``notify_appservices: false`` to the main config"
+                "\n"
+            )
+            sys.exit(1)
+
+        # Force the appservice to start since they will be disabled in the main config
+        config.notify_appservices = True
+
+    if config.worker_app == "synapse.app.pusher":
+        if config.start_pushers:
+            sys.stderr.write(
+                "\nThe pushers must be disabled in the main synapse process"
+                "\nbefore they can be run in a separate worker."
+                "\nPlease add ``start_pushers: false`` to the main config"
+                "\n"
+            )
+            sys.exit(1)
+
+        # Force the pushers to start since they will be disabled in the main config
+        config.start_pushers = True
+
+    if config.worker_app == "synapse.app.user_dir":
+        if config.update_user_directory:
+            sys.stderr.write(
+                "\nThe update_user_directory must be disabled in the main synapse process"
+                "\nbefore they can be run in a separate worker."
+                "\nPlease add ``update_user_directory: false`` to the main config"
+                "\n"
+            )
+            sys.exit(1)
+
+        # Force the pushers to start since they will be disabled in the main config
+        config.update_user_directory = True
+
+    if config.worker_app == "synapse.app.federation_sender":
+        if config.send_federation:
+            sys.stderr.write(
+                "\nThe send_federation must be disabled in the main synapse process"
+                "\nbefore they can be run in a separate worker."
+                "\nPlease add ``send_federation: false`` to the main config"
+                "\n"
+            )
+            sys.exit(1)
+
+        # Force the pushers to start since they will be disabled in the main config
+        config.send_federation = True
+
+    synapse.events.USE_FROZEN_DICTS = config.use_frozen_dicts
+
+    ss = GenericWorkerServer(
+        config.server_name,
+        config=config,
+        version_string="Synapse/" + get_version_string(synapse),
+    )
+
+    setup_logging(ss, config, use_worker_options=True)
+
+    ss.setup()
+    reactor.addSystemEventTrigger(
+        "before", "startup", _base.start, ss, config.worker_listeners
+    )
+
+    _base.start_worker_reactor("synapse-generic-worker", config)
+
+
+if __name__ == "__main__":
+    with LoggingContext("main"):
+        start(sys.argv[1:])