MatrixSynapse/synapse/replication/tcp/handler.py

280 lines
11 KiB
Python

# -*- 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'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()
# We protect catching up with a linearizer in case the replication
# connection reconnects under us.
with await self._position_linearizer.queue(cmd.stream_name):
# 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)
self._streams_connected.add(cmd.stream_name)
# Handle any RDATA that came in while we were catching up.
rows = self._pending_batches.pop(cmd.stream_name, [])
if rows:
# We need to make sure we filter out RDATA rows with a token less
# than what we've caught up to. This is slightly fiddly because of
# "batched" rows which have a `None` token, indicating that they
# have the same token as the next row with a non-None token.
#
# We do this by walking the list backwards, first removing any RDATA
# rows that are part of an uncompeted batch, then taking rows while
# their token is either None or greater than where we've caught up
# to.
uncompleted_batch = []
unfinished_batch = True
filtered_rows = []
for row in reversed(rows):
if row.token is not None:
unfinished_batch = False
if cmd.token < row.token:
filtered_rows.append(row)
else:
break
elif unfinished_batch:
uncompleted_batch.append(row)
else:
filtered_rows.append(row)
filtered_rows.reverse()
uncompleted_batch.reverse()
if uncompleted_batch:
self._pending_batches[cmd.stream_name] = uncompleted_batch
await self.on_rdata(cmd.stream_name, rows[-1].token, filtered_rows)
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))