synapse-product/synapse/replication/tcp/client.py
Richard van der Hoff 0e8d78f6aa Logcontexts for replication command handlers
Run the handlers for replication commands as background processes. This should
improve the visibility in our metrics, and reduce the number of "running db
transaction from sentinel context" warnings.

Ideally it means converting the things that fire off deferreds into the night
into things that actually return a Deferred when they are done. I've made a bit
of a stab at this, but it will probably be leaky.
2018-08-17 00:43:43 +01:00

207 lines
7.3 KiB
Python

# -*- 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 twisted.internet import defer
from twisted.internet.protocol import ReconnectingClientFactory
from .commands import (
FederationAckCommand,
InvalidateCacheCommand,
RemovePusherCommand,
UserIpCommand,
UserSyncCommand,
)
from .protocol import ClientReplicationStreamProtocol
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.
"""
maxDelay = 5 # Try at least once every N seconds
def __init__(self, hs, client_name, handler):
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)
self.resetDelay()
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(object):
"""A base handler that can be passed to the ReplicationClientFactory.
By default proxies incoming replication data to the SlaveStore.
"""
def __init__(self, store):
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 = []
# Map from string -> deferred, to wake up when receiveing a SYNC with
# the given string.
# Used for tests.
self.awaiting_syncs = {}
def start_replication(self, hs):
"""Helper method to start a replication connection to the remote server
using TCP.
"""
client_name = hs.config.worker_name
factory = ReplicationClientFactory(hs, client_name, self)
host = hs.config.worker_replication_host
port = hs.config.worker_replication_port
hs.get_reactor().connectTCP(host, port, factory)
def on_rdata(self, stream_name, token, rows):
"""Called when we get new replication data. By default this just pokes
the slave store.
Can be overriden in subclasses to handle more.
"""
logger.info("Received rdata %s -> %s", stream_name, token)
return self.store.process_replication_rows(stream_name, token, rows)
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.
"""
return 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 get_streams_to_replicate(self):
"""Called when a new connection has been established and we need to
subscribe to streams.
Returns a dictionary of stream name to token.
"""
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.warn("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 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 = []