forked-synapse/synapse/replication/tcp/resource.py
2020-03-20 14:40:47 +00:00

353 lines
13 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.
"""The server side of the replication stream.
"""
import logging
import random
from typing import Any, List
from six import itervalues
from prometheus_client import Counter
from twisted.internet.protocol import Factory
from synapse.metrics import LaterGauge
from synapse.metrics.background_process_metrics import run_as_background_process
from synapse.util.metrics import Measure, measure_func
from .protocol import ServerReplicationStreamProtocol
from .streams import STREAMS_MAP
from .streams.federation import FederationStream
stream_updates_counter = Counter(
"synapse_replication_tcp_resource_stream_updates", "", ["stream_name"]
)
user_sync_counter = Counter("synapse_replication_tcp_resource_user_sync", "")
federation_ack_counter = Counter("synapse_replication_tcp_resource_federation_ack", "")
remove_pusher_counter = Counter("synapse_replication_tcp_resource_remove_pusher", "")
invalidate_cache_counter = Counter(
"synapse_replication_tcp_resource_invalidate_cache", ""
)
user_ip_cache_counter = Counter("synapse_replication_tcp_resource_user_ip_cache", "")
logger = logging.getLogger(__name__)
class ReplicationStreamProtocolFactory(Factory):
"""Factory for new replication connections.
"""
def __init__(self, hs):
self.streamer = ReplicationStreamer(hs)
self.clock = hs.get_clock()
self.server_name = hs.config.server_name
def buildProtocol(self, addr):
return ServerReplicationStreamProtocol(
self.server_name, self.clock, self.streamer
)
class ReplicationStreamer(object):
"""Handles replication connections.
This needs to be poked when new replication data may be available. When new
data is available it will propagate to all connected clients.
"""
def __init__(self, hs):
self.store = hs.get_datastore()
self.presence_handler = hs.get_presence_handler()
self.clock = hs.get_clock()
self.notifier = hs.get_notifier()
self._server_notices_sender = hs.get_server_notices_sender()
self._replication_torture_level = hs.config.replication_torture_level
# Current connections.
self.connections = [] # type: List[ServerReplicationStreamProtocol]
LaterGauge(
"synapse_replication_tcp_resource_total_connections",
"",
[],
lambda: len(self.connections),
)
# List of streams that clients can subscribe to.
# We only support federation stream if federation sending hase been
# disabled on the master.
self.streams = [
stream(hs)
for stream in itervalues(STREAMS_MAP)
if stream != FederationStream or not hs.config.send_federation
]
self.streams_by_name = {stream.NAME: stream for stream in self.streams}
LaterGauge(
"synapse_replication_tcp_resource_connections_per_stream",
"",
["stream_name"],
lambda: {
(stream_name,): len(
[
conn
for conn in self.connections
if stream_name in conn.replication_streams
]
)
for stream_name in self.streams_by_name
},
)
self.federation_sender = None
if not hs.config.send_federation:
self.federation_sender = hs.get_federation_sender()
self.notifier.add_replication_callback(self.on_notifier_poke)
self.notifier.add_remote_server_up_callback(self.send_remote_server_up)
# Keeps track of whether we are currently checking for updates
self.is_looping = False
self.pending_updates = False
hs.get_reactor().addSystemEventTrigger("before", "shutdown", self.on_shutdown)
def on_shutdown(self):
# close all connections on shutdown
for conn in self.connections:
conn.send_error("server shutting down")
def on_notifier_poke(self):
"""Checks if there is actually any new data and sends it to the
connections if there are.
This should get called each time new data is available, even if it
is currently being executed, so that nothing gets missed
"""
if not self.connections:
# Don't bother if nothing is listening. We still need to advance
# the stream tokens otherwise they'll fall beihind forever
for stream in self.streams:
stream.discard_updates_and_advance()
return
self.pending_updates = True
if self.is_looping:
logger.debug("Notifier poke loop already running")
return
run_as_background_process("replication_notifier", self._run_notifier_loop)
async def _run_notifier_loop(self):
self.is_looping = True
try:
# Keep looping while there have been pokes about potential updates.
# This protects against the race where a stream we already checked
# gets an update while we're handling other streams.
while self.pending_updates:
self.pending_updates = False
with Measure(self.clock, "repl.stream.get_updates"):
all_streams = self.streams
if self._replication_torture_level is not None:
# there is no guarantee about ordering between the streams,
# so let's shuffle them around a bit when we are in torture mode.
all_streams = list(all_streams)
random.shuffle(all_streams)
for stream in all_streams:
if stream.last_token == stream.current_token():
continue
if self._replication_torture_level:
await self.clock.sleep(
self._replication_torture_level / 1000.0
)
logger.debug(
"Getting stream: %s: %s -> %s",
stream.NAME,
stream.last_token,
stream.current_token(),
)
try:
updates, current_token = await stream.get_updates()
except Exception:
logger.info("Failed to handle stream %s", stream.NAME)
raise
logger.debug(
"Sending %d updates to %d connections",
len(updates),
len(self.connections),
)
if updates:
logger.info(
"Streaming: %s -> %s", stream.NAME, updates[-1][0]
)
stream_updates_counter.labels(stream.NAME).inc(len(updates))
# Some streams return multiple rows with the same stream IDs,
# we need to make sure they get sent out in batches. We do
# this by setting the current token to all but the last of
# a series of updates with the same token to have a None
# token. See RdataCommand for more details.
batched_updates = _batch_updates(updates)
for conn in self.connections:
for token, row in batched_updates:
try:
conn.stream_update(stream.NAME, token, row)
except Exception:
logger.exception("Failed to replicate")
logger.debug("No more pending updates, breaking poke loop")
finally:
self.pending_updates = False
self.is_looping = False
@measure_func("repl.get_stream_updates")
async def get_stream_updates(self, stream_name, token):
"""For a given stream get all updates since token. This is called when
a client first subscribes to a stream.
"""
stream = self.streams_by_name.get(stream_name, None)
if not stream:
raise Exception("unknown stream %s", stream_name)
return await stream.get_updates_since(token)
@measure_func("repl.federation_ack")
def federation_ack(self, token):
"""We've received an ack for federation stream from a client.
"""
federation_ack_counter.inc()
if self.federation_sender:
self.federation_sender.federation_ack(token)
@measure_func("repl.on_user_sync")
async def on_user_sync(self, conn_id, user_id, is_syncing, last_sync_ms):
"""A client has started/stopped syncing on a worker.
"""
user_sync_counter.inc()
await self.presence_handler.update_external_syncs_row(
conn_id, user_id, is_syncing, last_sync_ms
)
@measure_func("repl.on_remove_pusher")
async def on_remove_pusher(self, app_id, push_key, user_id):
"""A client has asked us to remove a pusher
"""
remove_pusher_counter.inc()
await self.store.delete_pusher_by_app_id_pushkey_user_id(
app_id=app_id, pushkey=push_key, user_id=user_id
)
self.notifier.on_new_replication_data()
@measure_func("repl.on_invalidate_cache")
async def on_invalidate_cache(self, cache_func: str, keys: List[Any]):
"""The client has asked us to invalidate a cache
"""
invalidate_cache_counter.inc()
# We invalidate the cache locally, but then also stream that to other
# workers.
await self.store.invalidate_cache_and_stream(cache_func, tuple(keys))
@measure_func("repl.on_user_ip")
async def on_user_ip(
self, user_id, access_token, ip, user_agent, device_id, last_seen
):
"""The client saw a user request
"""
user_ip_cache_counter.inc()
await self.store.insert_client_ip(
user_id, access_token, ip, user_agent, device_id, last_seen
)
await self._server_notices_sender.on_user_ip(user_id)
@measure_func("repl.on_remote_server_up")
def on_remote_server_up(self, server: str):
self.notifier.notify_remote_server_up(server)
def send_remote_server_up(self, server: str):
for conn in self.connections:
conn.send_remote_server_up(server)
def send_sync_to_all_connections(self, data):
"""Sends a SYNC command to all clients.
Used in tests.
"""
for conn in self.connections:
conn.send_sync(data)
def new_connection(self, connection):
"""A new client connection has been established
"""
self.connections.append(connection)
def lost_connection(self, connection):
"""A client connection has been lost
"""
try:
self.connections.remove(connection)
except ValueError:
pass
# We need to tell the presence handler that the connection has been
# lost so that it can handle any ongoing syncs on that connection.
run_as_background_process(
"update_external_syncs_clear",
self.presence_handler.update_external_syncs_clear,
connection.conn_id,
)
def _batch_updates(updates):
"""Takes a list of updates of form [(token, row)] and sets the token to
None for all rows where the next row has the same token. This is used to
implement batching.
For example:
[(1, _), (1, _), (2, _), (3, _), (3, _)]
becomes:
[(None, _), (1, _), (2, _), (None, _), (3, _)]
"""
if not updates:
return []
new_updates = []
for i, update in enumerate(updates[:-1]):
if update[0] == updates[i + 1][0]:
new_updates.append((None, update[1]))
else:
new_updates.append(update)
new_updates.append(updates[-1])
return new_updates