# -*- coding: utf-8 -*- # Copyright 2017 Vector Creations 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. """A replication client for use by synapse workers. """ import logging from typing import Dict, List, Optional from twisted.internet import defer from twisted.internet.protocol import ReconnectingClientFactory from synapse.replication.slave.storage._base import BaseSlavedStore from synapse.replication.tcp.protocol import ( AbstractReplicationClientHandler, ClientReplicationStreamProtocol, ) from .commands import ( Command, FederationAckCommand, InvalidateCacheCommand, RemoteServerUpCommand, RemovePusherCommand, UserIpCommand, UserSyncCommand, ) logger = logging.getLogger(__name__) class ReplicationClientFactory(ReconnectingClientFactory): """Factory for building connections to the master. Will reconnect if the connection is lost. Accepts a handler that will be called when new data is available or data is required. """ initialDelay = 0.1 maxDelay = 1 # Try at least once every N seconds def __init__(self, hs, client_name, handler: AbstractReplicationClientHandler): self.client_name = client_name self.handler = handler self.server_name = hs.config.server_name self._clock = hs.get_clock() # As self.clock is defined in super class hs.get_reactor().addSystemEventTrigger("before", "shutdown", self.stopTrying) def startedConnecting(self, connector): logger.info("Connecting to replication: %r", connector.getDestination()) def buildProtocol(self, addr): logger.info("Connected to replication: %r", addr) return ClientReplicationStreamProtocol( self.client_name, self.server_name, self._clock, self.handler ) def clientConnectionLost(self, connector, reason): logger.error("Lost replication conn: %r", reason) ReconnectingClientFactory.clientConnectionLost(self, connector, reason) def clientConnectionFailed(self, connector, reason): logger.error("Failed to connect to replication: %r", reason) ReconnectingClientFactory.clientConnectionFailed(self, connector, reason) class ReplicationClientHandler(AbstractReplicationClientHandler): """A base handler that can be passed to the ReplicationClientFactory. By default proxies incoming replication data to the SlaveStore. """ def __init__(self, store: BaseSlavedStore): self.store = store # The current connection. None if we are currently (re)connecting self.connection = None # Any pending commands to be sent once a new connection has been # established self.pending_commands = [] # type: List[Command] # Map from string -> deferred, to wake up when receiveing a SYNC with # the given string. # Used for tests. self.awaiting_syncs = {} # type: Dict[str, defer.Deferred] # The factory used to create connections. self.factory = None # type: Optional[ReplicationClientFactory] 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, stream_name, token, rows): """Called to handle a batch of replication data with a given stream token. By default this just pokes the slave store. Can be overridden in subclasses to handle more. Args: stream_name (str): name of the replication stream for this batch of rows token (int): stream token for this batch of rows rows (list): a list of Stream.ROW_TYPE objects as returned by Stream.parse_row. """ logger.debug("Received rdata %s -> %s", stream_name, token) self.store.process_replication_rows(stream_name, token, rows) async def on_position(self, stream_name, token): """Called when we get new position data. By default this just pokes the slave store. Can be overriden in subclasses to handle more. """ self.store.process_replication_rows(stream_name, token, []) def on_sync(self, data): """When we received a SYNC we wake up any deferreds that were waiting for the sync with the given data. Used by tests. """ d = self.awaiting_syncs.pop(data, None) if d: d.callback(data) def on_remote_server_up(self, server: str): """Called when get a new REMOTE_SERVER_UP command.""" def get_streams_to_replicate(self) -> Dict[str, int]: """Called when a new connection has been established and we need to subscribe to streams. Returns: map from stream name to the most recent update we have for that stream (ie, the point we want to start replicating from) """ args = self.store.stream_positions() user_account_data = args.pop("user_account_data", None) room_account_data = args.pop("room_account_data", None) if user_account_data: args["account_data"] = user_account_data elif room_account_data: args["account_data"] = room_account_data return args 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. (Overriden by the synchrotron's only) """ return [] def send_command(self, cmd): """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("Queuing command as not connected: %r", cmd.NAME) self.pending_commands.append(cmd) def send_federation_ack(self, token): """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, user_id, is_syncing, last_sync_ms): """Poke the master that a user has started/stopped syncing. """ self.send_command(UserSyncCommand(user_id, is_syncing, last_sync_ms)) def send_remove_pusher(self, app_id, push_key, user_id): """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, keys): """Poke the master to invalidate a cache. """ cmd = InvalidateCacheCommand(cache_func.__name__, keys) self.send_command(cmd) def send_user_ip(self, user_id, access_token, ip, user_agent, device_id, last_seen): """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 await_sync(self, data): """Returns a deferred that is resolved when we receive a SYNC command with given data. [Not currently] used by tests. """ return self.awaiting_syncs.setdefault(data, defer.Deferred()) def update_connection(self, connection): """Called when a connection has been established (or lost with None). """ self.connection = connection if connection: for cmd in self.pending_commands: connection.send_command(cmd) self.pending_commands = [] 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()