diff options
Diffstat (limited to 'synapse/replication/tcp')
| -rw-r--r-- | synapse/replication/tcp/client.py | 2 | ||||
| -rw-r--r-- | synapse/replication/tcp/commands.py | 18 | ||||
| -rw-r--r-- | synapse/replication/tcp/handler.py | 50 | ||||
| -rw-r--r-- | synapse/replication/tcp/protocol.py | 38 | ||||
| -rw-r--r-- | synapse/replication/tcp/redis.py | 181 |
5 files changed, 255 insertions, 34 deletions
diff --git a/synapse/replication/tcp/client.py b/synapse/replication/tcp/client.py index 700ae79158..2d07b8b2d0 100644 --- a/synapse/replication/tcp/client.py +++ b/synapse/replication/tcp/client.py @@ -30,7 +30,7 @@ if TYPE_CHECKING: logger = logging.getLogger(__name__) -class ReplicationClientFactory(ReconnectingClientFactory): +class DirectTcpReplicationClientFactory(ReconnectingClientFactory): """Factory for building connections to the master. Will reconnect if the connection is lost. diff --git a/synapse/replication/tcp/commands.py b/synapse/replication/tcp/commands.py index 5ec89d0fb8..5002efe6a0 100644 --- a/synapse/replication/tcp/commands.py +++ b/synapse/replication/tcp/commands.py @@ -454,3 +454,21 @@ VALID_CLIENT_COMMANDS = ( ErrorCommand.NAME, RemoteServerUpCommand.NAME, ) + + +def parse_command_from_line(line: str) -> Command: + """Parses a command from a received line. + + Line should already be stripped of whitespace and be checked if blank. + """ + + idx = line.index(" ") + if idx >= 0: + cmd_name = line[:idx] + rest_of_line = line[idx + 1 :] + else: + cmd_name = line + rest_of_line = "" + + cmd_cls = COMMAND_MAP[cmd_name] + return cmd_cls.from_line(rest_of_line) diff --git a/synapse/replication/tcp/handler.py b/synapse/replication/tcp/handler.py index e32e68e8c4..5b5ee2c13e 100644 --- a/synapse/replication/tcp/handler.py +++ b/synapse/replication/tcp/handler.py @@ -30,8 +30,10 @@ from typing import ( from prometheus_client import Counter +from twisted.internet.protocol import ReconnectingClientFactory + from synapse.metrics import LaterGauge -from synapse.replication.tcp.client import ReplicationClientFactory +from synapse.replication.tcp.client import DirectTcpReplicationClientFactory from synapse.replication.tcp.commands import ( ClearUserSyncsCommand, Command, @@ -92,7 +94,7 @@ class ReplicationCommandHandler: self._pending_batches = {} # type: Dict[str, List[Any]] # The factory used to create connections. - self._factory = None # type: Optional[ReplicationClientFactory] + self._factory = None # type: Optional[ReconnectingClientFactory] # The currently connected connections. self._connections = [] # type: List[AbstractConnection] @@ -119,11 +121,45 @@ class ReplicationCommandHandler: """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) + if hs.config.redis.redis_enabled: + from synapse.replication.tcp.redis import ( + RedisDirectTcpReplicationClientFactory, + ) + import txredisapi + + logger.info( + "Connecting to redis (host=%r port=%r DBID=%r)", + hs.config.redis_host, + hs.config.redis_port, + hs.config.redis_dbid, + ) + + # We need two connections to redis, one for the subscription stream and + # one to send commands to (as you can't send further redis commands to a + # connection after SUBSCRIBE is called). + + # First create the connection for sending commands. + outbound_redis_connection = txredisapi.lazyConnection( + host=hs.config.redis_host, + port=hs.config.redis_port, + dbid=hs.config.redis_dbid, + password=hs.config.redis.redis_password, + reconnect=True, + ) + + # Now create the factory/connection for the subscription stream. + self._factory = RedisDirectTcpReplicationClientFactory( + hs, outbound_redis_connection + ) + hs.get_reactor().connectTCP( + hs.config.redis.redis_host, hs.config.redis.redis_port, self._factory, + ) + else: + client_name = hs.config.worker_name + self._factory = DirectTcpReplicationClientFactory(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. diff --git a/synapse/replication/tcp/protocol.py b/synapse/replication/tcp/protocol.py index 9276ed2965..7240acb0a2 100644 --- a/synapse/replication/tcp/protocol.py +++ b/synapse/replication/tcp/protocol.py @@ -63,7 +63,6 @@ from twisted.python.failure import Failure from synapse.metrics import LaterGauge from synapse.metrics.background_process_metrics import run_as_background_process from synapse.replication.tcp.commands import ( - COMMAND_MAP, VALID_CLIENT_COMMANDS, VALID_SERVER_COMMANDS, Command, @@ -72,6 +71,7 @@ from synapse.replication.tcp.commands import ( PingCommand, ReplicateCommand, ServerCommand, + parse_command_from_line, ) from synapse.types import Collection from synapse.util import Clock @@ -210,38 +210,24 @@ class BaseReplicationStreamProtocol(LineOnlyReceiver): linestr = line.decode("utf-8") - # split at the first " ", handling one-word commands - idx = linestr.index(" ") - if idx >= 0: - cmd_name = linestr[:idx] - rest_of_line = linestr[idx + 1 :] - else: - cmd_name = linestr - rest_of_line = "" + try: + cmd = parse_command_from_line(linestr) + except Exception as e: + logger.exception("[%s] failed to parse line: %r", self.id(), linestr) + self.send_error("failed to parse line: %r (%r):" % (e, linestr)) + return - if cmd_name not in self.VALID_INBOUND_COMMANDS: - logger.error("[%s] invalid command %s", self.id(), cmd_name) - self.send_error("invalid command: %s", cmd_name) + if cmd.NAME not in self.VALID_INBOUND_COMMANDS: + logger.error("[%s] invalid command %s", self.id(), cmd.NAME) + self.send_error("invalid command: %s", cmd.NAME) return self.last_received_command = self.clock.time_msec() - self.inbound_commands_counter[cmd_name] = ( - self.inbound_commands_counter[cmd_name] + 1 + self.inbound_commands_counter[cmd.NAME] = ( + self.inbound_commands_counter[cmd.NAME] + 1 ) - cmd_cls = COMMAND_MAP[cmd_name] - try: - cmd = cmd_cls.from_line(rest_of_line) - except Exception as e: - logger.exception( - "[%s] failed to parse line %r: %r", self.id(), cmd_name, rest_of_line - ) - self.send_error( - "failed to parse line for %r: %r (%r):" % (cmd_name, e, rest_of_line) - ) - return - # Now lets try and call on_<CMD_NAME> function run_as_background_process( "replication-" + cmd.get_logcontext_id(), self.handle_command, cmd diff --git a/synapse/replication/tcp/redis.py b/synapse/replication/tcp/redis.py new file mode 100644 index 0000000000..4c08425735 --- /dev/null +++ b/synapse/replication/tcp/redis.py @@ -0,0 +1,181 @@ +# -*- coding: utf-8 -*- +# 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 TYPE_CHECKING + +import txredisapi + +from synapse.logging.context import PreserveLoggingContext +from synapse.metrics.background_process_metrics import run_as_background_process +from synapse.replication.tcp.commands import ( + Command, + ReplicateCommand, + parse_command_from_line, +) +from synapse.replication.tcp.protocol import AbstractConnection + +if TYPE_CHECKING: + from synapse.replication.tcp.handler import ReplicationCommandHandler + from synapse.server import HomeServer + +logger = logging.getLogger(__name__) + + +class RedisSubscriber(txredisapi.SubscriberProtocol, AbstractConnection): + """Connection to redis subscribed to replication stream. + + Parses incoming messages from redis into replication commands, and passes + them to `ReplicationCommandHandler` + + Due to the vagaries of `txredisapi` we don't want to have a custom + constructor, so instead we expect the defined attributes below to be set + immediately after initialisation. + + Attributes: + handler: The command handler to handle incoming commands. + stream_name: The *redis* stream name to subscribe to (not anything to + do with Synapse replication streams). + outbound_redis_connection: The connection to redis to use to send + commands. + """ + + handler = None # type: ReplicationCommandHandler + stream_name = None # type: str + outbound_redis_connection = None # type: txredisapi.RedisProtocol + + def connectionMade(self): + logger.info("Connected to redis instance") + self.subscribe(self.stream_name) + self.send_command(ReplicateCommand()) + + self.handler.new_connection(self) + + def messageReceived(self, pattern: str, channel: str, message: str): + """Received a message from redis. + """ + + if message.strip() == "": + # Ignore blank lines + return + + try: + cmd = parse_command_from_line(message) + except Exception: + logger.exception( + "[%s] failed to parse line: %r", message, + ) + return + + # Now lets try and call on_<CMD_NAME> function + run_as_background_process( + "replication-" + cmd.get_logcontext_id(), self.handle_command, cmd + ) + + async def handle_command(self, cmd: Command): + """Handle a command we have received over the replication stream. + + By default delegates to on_<COMMAND>, which should return an awaitable. + + Args: + cmd: received command + """ + handled = False + + # First call any command handlers on this instance. These are for redis + # specific handling. + cmd_func = getattr(self, "on_%s" % (cmd.NAME,), None) + if cmd_func: + await cmd_func(cmd) + handled = True + + # Then call out to the handler. + cmd_func = getattr(self.handler, "on_%s" % (cmd.NAME,), None) + if cmd_func: + await cmd_func(cmd) + handled = True + + if not handled: + logger.warning("Unhandled command: %r", cmd) + + def connectionLost(self, reason): + logger.info("Lost connection to redis instance") + self.handler.lost_connection(self) + + def send_command(self, cmd: Command): + """Send a command if connection has been established. + + Args: + cmd (Command) + """ + string = "%s %s" % (cmd.NAME, cmd.to_line()) + if "\n" in string: + raise Exception("Unexpected newline in command: %r", string) + + encoded_string = string.encode("utf-8") + + async def _send(): + with PreserveLoggingContext(): + # Note that we use the other connection as we can't send + # commands using the subscription connection. + await self.outbound_redis_connection.publish( + self.stream_name, encoded_string + ) + + run_as_background_process("send-cmd", _send) + + +class RedisDirectTcpReplicationClientFactory(txredisapi.SubscriberFactory): + """This is a reconnecting factory that connects to redis and immediately + subscribes to a stream. + + Args: + hs + outbound_redis_connection: A connection to redis that will be used to + send outbound commands (this is seperate to the redis connection + used to subscribe). + """ + + maxDelay = 5 + continueTrying = True + protocol = RedisSubscriber + + def __init__( + self, hs: "HomeServer", outbound_redis_connection: txredisapi.RedisProtocol + ): + + super().__init__() + + # This sets the password on the RedisFactory base class (as + # SubscriberFactory constructor doesn't pass it through). + self.password = hs.config.redis.redis_password + + self.handler = hs.get_tcp_replication() + self.stream_name = hs.hostname + + self.outbound_redis_connection = outbound_redis_connection + + def buildProtocol(self, addr): + p = super().buildProtocol(addr) # type: RedisSubscriber + + # We do this here rather than add to the constructor of `RedisSubcriber` + # as to do so would involve overriding `buildProtocol` entirely, however + # the base method does some other things than just instantiating the + # protocol. + p.handler = self.handler + p.outbound_redis_connection = self.outbound_redis_connection + p.stream_name = self.stream_name + + return p |