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Diffstat (limited to 'synapse/replication/tcp/handler.py')
| -rw-r--r-- | synapse/replication/tcp/handler.py | 252 |
1 files changed, 252 insertions, 0 deletions
diff --git a/synapse/replication/tcp/handler.py b/synapse/replication/tcp/handler.py new file mode 100644 index 0000000000..12a1cfd6d1 --- /dev/null +++ b/synapse/replication/tcp/handler.py @@ -0,0 +1,252 @@ +# -*- 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 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 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() + + # 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) + + # Handle any RDATA that came in while we were catching up. + rows = self._pending_batches.pop(cmd.stream_name, []) + if rows: + await self._replication_data_handler.on_rdata( + cmd.stream_name, rows[-1].token, rows + ) + + self._streams_connected.add(cmd.stream_name) + + 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)) |