# -*- 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.replication.tcp.client import ReplicationClientFactory from synapse.replication.tcp.commands import ( Command, FederationAckCommand, InvalidateCacheCommand, PositionCommand, RdataCommand, RemoteServerUpCommand, RemovePusherCommand, SyncCommand, UserIpCommand, UserSyncCommand, ) 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"] ) 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() # 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 current connection. None if we are currently (re)connecting self._connection = None 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_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 if cmd.token is None or stream_name not in self._streams_connected: # I.e. either 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) or we're currently connecting so we queue up rows. 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're about to go and catch up with the stream, so mark as connecting # to stop RDATA being handled at the same time by removing stream from # list of connected streams. We also clear any batched up RDATA from # before we got the POSITION. self._streams_connected.discard(cmd.stream_name) self._pending_batches.clear() # We protect catching up with a linearizer in case the replication # connection reconnects under us. with await self._position_linearizer.queue(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 # Fetch all updates between then and now. limited = True while limited: updates, current_token, limited = 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) # Handle any RDATA that came in while we were catching up. rows = self._pending_batches.pop(cmd.stream_name, []) if rows: # We need to make sure we filter out RDATA rows with a token less # than what we've caught up to. This is slightly fiddly because of # "batched" rows which have a `None` token, indicating that they # have the same token as the next row with a non-None token. # # We do this by walking the list backwards, first removing any RDATA # rows that are part of an uncompeted batch, then taking rows while # their token is either None or greater than where we've caught up # to. uncompleted_batch = [] unfinished_batch = True filtered_rows = [] for row in reversed(rows): if row.token is not None: unfinished_batch = False if cmd.token < row.token: filtered_rows.append(row) else: break elif unfinished_batch: uncompleted_batch.append(row) else: filtered_rows.append(row) filtered_rows.reverse() uncompleted_batch.reverse() if uncompleted_batch: self._pending_batches[cmd.stream_name] = uncompleted_batch await self.on_rdata(cmd.stream_name, rows[-1].token, filtered_rows) async def on_SYNC(self, cmd: SyncCommand): pass 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) 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 update_connection(self, connection): """Called when a connection has been established (or lost with None). """ self._connection = connection def finished_connecting(self): """Called when we have successfully subscribed and caught up to all streams we're interested in. """ logger.info("Finished connecting to server") # We don't reset the delay any earlier as otherwise if there is a # problem during start up we'll end up tight looping connecting to the # server. if self._factory: self._factory.resetDelay() def send_command(self, cmd: Command): """Send a command to master (when we get establish a connection if we don't have one already.) """ if self._connection: self._connection.send_command(cmd) 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))