synapse-product/synapse/replication/tcp/handler.py

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# -*- 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.metrics import LaterGauge
from synapse.replication.tcp.client import ReplicationClientFactory
from synapse.replication.tcp.commands import (
ClearUserSyncsCommand,
Command,
FederationAckCommand,
InvalidateCacheCommand,
PositionCommand,
RdataCommand,
RemoteServerUpCommand,
RemovePusherCommand,
ReplicateCommand,
UserIpCommand,
UserSyncCommand,
)
from synapse.replication.tcp.protocol import AbstractConnection
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"]
)
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", "")
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()
self._store = hs.get_datastore()
self._notifier = hs.get_notifier()
self._clock = hs.get_clock()
self._instance_id = hs.get_instance_id()
# 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 currently connected connections.
self._connections = [] # type: List[AbstractConnection]
LaterGauge(
"synapse_replication_tcp_resource_total_connections",
"",
[],
lambda: len(self._connections),
)
self._is_master = hs.config.worker_app is None
self._federation_sender = None
if self._is_master and not hs.config.send_federation:
self._federation_sender = hs.get_federation_sender()
self._server_notices_sender = None
if self._is_master:
self._server_notices_sender = hs.get_server_notices_sender()
self._notifier.add_remote_server_up_callback(self.send_remote_server_up)
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_REPLICATE(self, cmd: ReplicateCommand):
# We only want to announce positions by the writer of the streams.
# Currently this is just the master process.
if not self._is_master:
return
for stream_name, stream in self._streams.items():
current_token = stream.current_token()
self.send_command(PositionCommand(stream_name, current_token))
async def on_USER_SYNC(self, cmd: UserSyncCommand):
user_sync_counter.inc()
if self._is_master:
await self._presence_handler.update_external_syncs_row(
cmd.instance_id, cmd.user_id, cmd.is_syncing, cmd.last_sync_ms
)
async def on_CLEAR_USER_SYNC(self, cmd: ClearUserSyncsCommand):
if self._is_master:
await self._presence_handler.update_external_syncs_clear(cmd.instance_id)
async def on_FEDERATION_ACK(self, cmd: FederationAckCommand):
federation_ack_counter.inc()
if self._federation_sender:
self._federation_sender.federation_ack(cmd.token)
async def on_REMOVE_PUSHER(self, cmd: RemovePusherCommand):
remove_pusher_counter.inc()
if self._is_master:
await self._store.delete_pusher_by_app_id_pushkey_user_id(
app_id=cmd.app_id, pushkey=cmd.push_key, user_id=cmd.user_id
)
self._notifier.on_new_replication_data()
async def on_INVALIDATE_CACHE(self, cmd: InvalidateCacheCommand):
invalidate_cache_counter.inc()
if self._is_master:
# We invalidate the cache locally, but then also stream that to other
# workers.
await self._store.invalidate_cache_and_stream(
cmd.cache_func, tuple(cmd.keys)
)
async def on_USER_IP(self, cmd: UserIpCommand):
user_ip_cache_counter.inc()
if self._is_master:
await self._store.insert_client_ip(
cmd.user_id,
cmd.access_token,
cmd.ip,
cmd.user_agent,
cmd.device_id,
cmd.last_seen,
)
if self._server_notices_sender:
await self._server_notices_sender.on_user_ip(cmd.user_id)
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
# We linearize here for two reasons:
# 1. so we don't try and concurrently handle multiple rows for the
# same stream, and
# 2. so we don't race with getting a POSITION command and fetching
# missing RDATA.
with await self._position_linearizer.queue(cmd.stream_name):
if stream_name not in self._streams_connected:
# If the stream isn't marked as connected then we haven't seen a
# `POSITION` command yet, and so we may have missed some rows.
# Let's drop the row for now, on the assumption we'll receive a
# `POSITION` soon and we'll catch up correctly then.
logger.warning(
"Discarding RDATA for unconnected stream %s -> %s",
stream_name,
cmd.token,
)
return
if cmd.token is None:
# I.e. 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).
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 protect catching up with a linearizer in case the replication
# connection reconnects under us.
with await self._position_linearizer.queue(cmd.stream_name):
# We're about to go and catch up with the stream, so remove from set
# of connected streams.
self._streams_connected.discard(cmd.stream_name)
# We clear the pending batches for the stream as the fetching of the
# missing updates below will fetch all rows in the batch.
self._pending_batches.pop(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
# If the position token matches our current token then we're up to
# date and there's nothing to do. Otherwise, fetch all updates
# between then and now.
missing_updates = cmd.token != current_token
while missing_updates:
(
updates,
current_token,
missing_updates,
) = 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)
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)
if self._is_master:
self._notifier.notify_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 new_connection(self, connection: AbstractConnection):
"""Called when we have a new connection.
"""
self._connections.append(connection)
# If we are connected to replication as a client (rather than a server)
# we need to reset the reconnection delay on the client factory (which
# is used to do exponential back off when the connection drops).
#
# Ideally we would reset the delay when we've "fully established" the
# connection (for some definition thereof) to stop us from tightlooping
# on reconnection if something fails after this point and we drop the
# connection. Unfortunately, we don't really have a better definition of
# "fully established" than the connection being established.
if self._factory:
self._factory.resetDelay()
# Tell the server if we have any users currently syncing (should only
# happen on synchrotrons)
currently_syncing = self.get_currently_syncing_users()
now = self._clock.time_msec()
for user_id in currently_syncing:
connection.send_command(
UserSyncCommand(self._instance_id, user_id, True, now)
)
def lost_connection(self, connection: AbstractConnection):
"""Called when a connection is closed/lost.
"""
try:
self._connections.remove(connection)
except ValueError:
pass
def connected(self) -> bool:
"""Do we have any replication connections open?
Is used by e.g. `ReplicationStreamer` to no-op if nothing is connected.
"""
return bool(self._connections)
def send_command(self, cmd: Command):
"""Send a command to all connected connections.
"""
if self._connections:
for connection in self._connections:
try:
connection.send_command(cmd)
except Exception:
# We probably want to catch some types of exceptions here
# and log them as warnings (e.g. connection gone), but I
# can't find what those exception types they would be.
logger.exception(
"Failed to write command %s to connection %s",
cmd.NAME,
connection,
)
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))
def stream_update(self, stream_name: str, token: str, data: Any):
"""Called when a new update is available to stream to clients.
We need to check if the client is interested in the stream or not
"""
self.send_command(RdataCommand(stream_name, token, data))