# -*- coding: utf-8 -*- # Copyright 2017 Vector Creations 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 logging from typing import Any, Callable, Dict, List, Optional, Set from prometheus_client import Counter from synapse.metrics import LaterGauge from synapse.replication.tcp.client import ReplicationClientFactory from synapse.replication.tcp.commands import ( ClearUserSyncsCommand, Command, FederationAckCommand, InvalidateCacheCommand, PositionCommand, RdataCommand, RemoteServerUpCommand, RemovePusherCommand, ReplicateCommand, UserIpCommand, UserSyncCommand, ) from synapse.replication.tcp.protocol import AbstractConnection from synapse.replication.tcp.streams import STREAMS_MAP, Stream from synapse.util.async_helpers import Linearizer logger = logging.getLogger(__name__) # number of updates received for each RDATA stream inbound_rdata_count = Counter( "synapse_replication_tcp_protocol_inbound_rdata_count", "", ["stream_name"] ) user_sync_counter = Counter("synapse_replication_tcp_resource_user_sync", "") federation_ack_counter = Counter("synapse_replication_tcp_resource_federation_ack", "") remove_pusher_counter = Counter("synapse_replication_tcp_resource_remove_pusher", "") invalidate_cache_counter = Counter( "synapse_replication_tcp_resource_invalidate_cache", "" ) user_ip_cache_counter = Counter("synapse_replication_tcp_resource_user_ip_cache", "") class ReplicationCommandHandler: """Handles incoming commands from replication as well as sending commands back out to connections. """ def __init__(self, hs): self._replication_data_handler = hs.get_replication_data_handler() self._presence_handler = hs.get_presence_handler() self._store = hs.get_datastore() self._notifier = hs.get_notifier() self._clock = hs.get_clock() self._instance_id = hs.get_instance_id() # Set of streams that we've caught up with. self._streams_connected = set() # type: Set[str] self._streams = { stream.NAME: stream(hs) for stream in STREAMS_MAP.values() } # type: Dict[str, Stream] self._position_linearizer = Linearizer("replication_position") # Map of stream to batched updates. See RdataCommand for info on how # batching works. self._pending_batches = {} # type: Dict[str, List[Any]] # The factory used to create connections. self._factory = None # type: Optional[ReplicationClientFactory] # The currently connected connections. self._connections = [] # type: List[AbstractConnection] LaterGauge( "synapse_replication_tcp_resource_total_connections", "", [], lambda: len(self._connections), ) self._is_master = hs.config.worker_app is None self._federation_sender = None if self._is_master and not hs.config.send_federation: self._federation_sender = hs.get_federation_sender() self._server_notices_sender = None if self._is_master: self._server_notices_sender = hs.get_server_notices_sender() self._notifier.add_remote_server_up_callback(self.send_remote_server_up) def start_replication(self, hs): """Helper method to start a replication connection to the remote server using TCP. """ client_name = hs.config.worker_name self._factory = ReplicationClientFactory(hs, client_name, self) host = hs.config.worker_replication_host port = hs.config.worker_replication_port hs.get_reactor().connectTCP(host, port, self._factory) async def on_REPLICATE(self, cmd: ReplicateCommand): # We only want to announce positions by the writer of the streams. # Currently this is just the master process. if not self._is_master: return for stream_name, stream in self._streams.items(): current_token = stream.current_token() self.send_command(PositionCommand(stream_name, current_token)) async def on_USER_SYNC(self, cmd: UserSyncCommand): user_sync_counter.inc() if self._is_master: await self._presence_handler.update_external_syncs_row( cmd.instance_id, cmd.user_id, cmd.is_syncing, cmd.last_sync_ms ) async def on_CLEAR_USER_SYNC(self, cmd: ClearUserSyncsCommand): if self._is_master: await self._presence_handler.update_external_syncs_clear(cmd.instance_id) async def on_FEDERATION_ACK(self, cmd: FederationAckCommand): federation_ack_counter.inc() if self._federation_sender: self._federation_sender.federation_ack(cmd.token) async def on_REMOVE_PUSHER(self, cmd: RemovePusherCommand): remove_pusher_counter.inc() if self._is_master: await self._store.delete_pusher_by_app_id_pushkey_user_id( app_id=cmd.app_id, pushkey=cmd.push_key, user_id=cmd.user_id ) self._notifier.on_new_replication_data() async def on_INVALIDATE_CACHE(self, cmd: InvalidateCacheCommand): invalidate_cache_counter.inc() if self._is_master: # We invalidate the cache locally, but then also stream that to other # workers. await self._store.invalidate_cache_and_stream( cmd.cache_func, tuple(cmd.keys) ) async def on_USER_IP(self, cmd: UserIpCommand): user_ip_cache_counter.inc() if self._is_master: await self._store.insert_client_ip( cmd.user_id, cmd.access_token, cmd.ip, cmd.user_agent, cmd.device_id, cmd.last_seen, ) if self._server_notices_sender: await self._server_notices_sender.on_user_ip(cmd.user_id) async def on_RDATA(self, cmd: RdataCommand): stream_name = cmd.stream_name inbound_rdata_count.labels(stream_name).inc() try: row = STREAMS_MAP[stream_name].parse_row(cmd.row) except Exception: logger.exception("Failed to parse RDATA: %r %r", stream_name, cmd.row) raise # We linearize here for two reasons: # 1. so we don't try and concurrently handle multiple rows for the # same stream, and # 2. so we don't race with getting a POSITION command and fetching # missing RDATA. with await self._position_linearizer.queue(cmd.stream_name): if stream_name not in self._streams_connected: # If the stream isn't marked as connected then we haven't seen a # `POSITION` command yet, and so we may have missed some rows. # Let's drop the row for now, on the assumption we'll receive a # `POSITION` soon and we'll catch up correctly then. logger.warning( "Discarding RDATA for unconnected stream %s -> %s", stream_name, cmd.token, ) return if cmd.token is None: # I.e. this is part of a batch of updates for this stream (in # which case batch until we get an update for the stream with a non # None token). self._pending_batches.setdefault(stream_name, []).append(row) else: # Check if this is the last of a batch of updates rows = self._pending_batches.pop(stream_name, []) rows.append(row) await self.on_rdata(stream_name, cmd.token, rows) async def on_rdata(self, stream_name: str, token: int, rows: list): """Called to handle a batch of replication data with a given stream token. Args: stream_name: name of the replication stream for this batch of rows token: stream token for this batch of rows rows: a list of Stream.ROW_TYPE objects as returned by Stream.parse_row. """ logger.debug("Received rdata %s -> %s", stream_name, token) await self._replication_data_handler.on_rdata(stream_name, token, rows) async def on_POSITION(self, cmd: PositionCommand): stream = self._streams.get(cmd.stream_name) if not stream: logger.error("Got POSITION for unknown stream: %s", cmd.stream_name) return # We protect catching up with a linearizer in case the replication # connection reconnects under us. with await self._position_linearizer.queue(cmd.stream_name): # We're about to go and catch up with the stream, so remove from set # of connected streams. self._streams_connected.discard(cmd.stream_name) # We clear the pending batches for the stream as the fetching of the # missing updates below will fetch all rows in the batch. self._pending_batches.pop(cmd.stream_name, []) # Find where we previously streamed up to. current_token = self._replication_data_handler.get_streams_to_replicate().get( cmd.stream_name ) if current_token is None: logger.warning( "Got POSITION for stream we're not subscribed to: %s", cmd.stream_name, ) return # If the position token matches our current token then we're up to # date and there's nothing to do. Otherwise, fetch all updates # between then and now. missing_updates = cmd.token != current_token while missing_updates: ( updates, current_token, missing_updates, ) = await stream.get_updates_since(current_token, cmd.token) if updates: await self.on_rdata( cmd.stream_name, current_token, [stream.parse_row(update[1]) for update in updates], ) # We've now caught up to position sent to us, notify handler. await self._replication_data_handler.on_position(cmd.stream_name, cmd.token) self._streams_connected.add(cmd.stream_name) async def on_REMOTE_SERVER_UP(self, cmd: RemoteServerUpCommand): """"Called when get a new REMOTE_SERVER_UP command.""" self._replication_data_handler.on_remote_server_up(cmd.data) if self._is_master: self._notifier.notify_remote_server_up(cmd.data) def get_currently_syncing_users(self): """Get the list of currently syncing users (if any). This is called when a connection has been established and we need to send the currently syncing users. """ return self._presence_handler.get_currently_syncing_users() def new_connection(self, connection: AbstractConnection): """Called when we have a new connection. """ self._connections.append(connection) # If we are connected to replication as a client (rather than a server) # we need to reset the reconnection delay on the client factory (which # is used to do exponential back off when the connection drops). # # Ideally we would reset the delay when we've "fully established" the # connection (for some definition thereof) to stop us from tightlooping # on reconnection if something fails after this point and we drop the # connection. Unfortunately, we don't really have a better definition of # "fully established" than the connection being established. if self._factory: self._factory.resetDelay() # Tell the server if we have any users currently syncing (should only # happen on synchrotrons) currently_syncing = self.get_currently_syncing_users() now = self._clock.time_msec() for user_id in currently_syncing: connection.send_command( UserSyncCommand(self._instance_id, user_id, True, now) ) def lost_connection(self, connection: AbstractConnection): """Called when a connection is closed/lost. """ try: self._connections.remove(connection) except ValueError: pass def connected(self) -> bool: """Do we have any replication connections open? Is used by e.g. `ReplicationStreamer` to no-op if nothing is connected. """ return bool(self._connections) def send_command(self, cmd: Command): """Send a command to all connected connections. """ if self._connections: for connection in self._connections: try: connection.send_command(cmd) except Exception: # We probably want to catch some types of exceptions here # and log them as warnings (e.g. connection gone), but I # can't find what those exception types they would be. logger.exception( "Failed to write command %s to connection %s", cmd.NAME, connection, ) else: logger.warning("Dropping command as not connected: %r", cmd.NAME) def send_federation_ack(self, token: int): """Ack data for the federation stream. This allows the master to drop data stored purely in memory. """ self.send_command(FederationAckCommand(token)) def send_user_sync( self, instance_id: str, user_id: str, is_syncing: bool, last_sync_ms: int ): """Poke the master that a user has started/stopped syncing. """ self.send_command( UserSyncCommand(instance_id, user_id, is_syncing, last_sync_ms) ) def send_remove_pusher(self, app_id: str, push_key: str, user_id: str): """Poke the master to remove a pusher for a user """ cmd = RemovePusherCommand(app_id, push_key, user_id) self.send_command(cmd) def send_invalidate_cache(self, cache_func: Callable, keys: tuple): """Poke the master to invalidate a cache. """ cmd = InvalidateCacheCommand(cache_func.__name__, keys) self.send_command(cmd) def send_user_ip( self, user_id: str, access_token: str, ip: str, user_agent: str, device_id: str, last_seen: int, ): """Tell the master that the user made a request. """ cmd = UserIpCommand(user_id, access_token, ip, user_agent, device_id, last_seen) self.send_command(cmd) def send_remote_server_up(self, server: str): self.send_command(RemoteServerUpCommand(server)) def stream_update(self, stream_name: str, token: str, data: Any): """Called when a new update is available to stream to clients. We need to check if the client is interested in the stream or not """ self.send_command(RdataCommand(stream_name, token, data))