# -*- coding: utf-8 -*- # Copyright 2014-2016 OpenMarket Ltd # Copyright 2019 New Vector 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. import datetime import logging from prometheus_client import Counter from twisted.internet import defer from synapse.api.errors import ( FederationDeniedError, HttpResponseException, RequestSendFailed, ) from synapse.events import EventBase from synapse.federation.units import Edu from synapse.handlers.presence import format_user_presence_state from synapse.metrics import sent_transactions_counter from synapse.metrics.background_process_metrics import run_as_background_process from synapse.storage.presence import UserPresenceState from synapse.util.retryutils import NotRetryingDestination, get_retry_limiter # This is defined in the Matrix spec and enforced by the receiver. MAX_EDUS_PER_TRANSACTION = 100 logger = logging.getLogger(__name__) sent_edus_counter = Counter( "synapse_federation_client_sent_edus", "Total number of EDUs successfully sent" ) sent_edus_by_type = Counter( "synapse_federation_client_sent_edus_by_type", "Number of sent EDUs successfully sent, by event type", ["type"], ) class PerDestinationQueue(object): """ Manages the per-destination transmission queues. Args: hs (synapse.HomeServer): transaction_sender (TransactionManager): destination (str): the server_name of the destination that we are managing transmission for. """ def __init__(self, hs, transaction_manager, destination): self._server_name = hs.hostname self._clock = hs.get_clock() self._store = hs.get_datastore() self._transaction_manager = transaction_manager self._destination = destination self.transmission_loop_running = False # a list of tuples of (pending pdu, order) self._pending_pdus = [] # type: list[tuple[EventBase, int]] self._pending_edus = [] # type: list[Edu] # Pending EDUs by their "key". Keyed EDUs are EDUs that get clobbered # based on their key (e.g. typing events by room_id) # Map of (edu_type, key) -> Edu self._pending_edus_keyed = {} # type: dict[tuple[str, str], Edu] # Map of user_id -> UserPresenceState of pending presence to be sent to this # destination self._pending_presence = {} # type: dict[str, UserPresenceState] # room_id -> receipt_type -> user_id -> receipt_dict self._pending_rrs = {} self._rrs_pending_flush = False # stream_id of last successfully sent to-device message. # NB: may be a long or an int. self._last_device_stream_id = 0 # stream_id of last successfully sent device list update. self._last_device_list_stream_id = 0 def __str__(self): return "PerDestinationQueue[%s]" % self._destination def pending_pdu_count(self): return len(self._pending_pdus) def pending_edu_count(self): return ( len(self._pending_edus) + len(self._pending_presence) + len(self._pending_edus_keyed) ) def send_pdu(self, pdu, order): """Add a PDU to the queue, and start the transmission loop if neccessary Args: pdu (EventBase): pdu to send order (int): """ self._pending_pdus.append((pdu, order)) self.attempt_new_transaction() def send_presence(self, states): """Add presence updates to the queue. Start the transmission loop if neccessary. Args: states (iterable[UserPresenceState]): presence to send """ self._pending_presence.update({state.user_id: state for state in states}) self.attempt_new_transaction() def queue_read_receipt(self, receipt): """Add a RR to the list to be sent. Doesn't start the transmission loop yet (see flush_read_receipts_for_room) Args: receipt (synapse.api.receipt_info.ReceiptInfo): receipt to be queued """ self._pending_rrs.setdefault(receipt.room_id, {}).setdefault( receipt.receipt_type, {} )[receipt.user_id] = {"event_ids": receipt.event_ids, "data": receipt.data} def flush_read_receipts_for_room(self, room_id): # if we don't have any read-receipts for this room, it may be that we've already # sent them out, so we don't need to flush. if room_id not in self._pending_rrs: return self._rrs_pending_flush = True self.attempt_new_transaction() def send_keyed_edu(self, edu, key): self._pending_edus_keyed[(edu.edu_type, key)] = edu self.attempt_new_transaction() def send_edu(self, edu): self._pending_edus.append(edu) self.attempt_new_transaction() def attempt_new_transaction(self): """Try to start a new transaction to this destination If there is already a transaction in progress to this destination, returns immediately. Otherwise kicks off the process of sending a transaction in the background. """ # list of (pending_pdu, deferred, order) if self.transmission_loop_running: # XXX: this can get stuck on by a never-ending # request at which point pending_pdus just keeps growing. # we need application-layer timeouts of some flavour of these # requests logger.debug("TX [%s] Transaction already in progress", self._destination) return logger.debug("TX [%s] Starting transaction loop", self._destination) run_as_background_process( "federation_transaction_transmission_loop", self._transaction_transmission_loop, ) @defer.inlineCallbacks def _transaction_transmission_loop(self): pending_pdus = [] try: self.transmission_loop_running = True # This will throw if we wouldn't retry. We do this here so we fail # quickly, but we will later check this again in the http client, # hence why we throw the result away. yield get_retry_limiter(self._destination, self._clock, self._store) pending_pdus = [] while True: # We have to keep 2 free slots for presence and rr_edus limit = MAX_EDUS_PER_TRANSACTION - 2 device_update_edus, dev_list_id = yield self._get_device_update_edus( limit ) limit -= len(device_update_edus) ( to_device_edus, device_stream_id, ) = yield self._get_to_device_message_edus(limit) pending_edus = device_update_edus + to_device_edus # BEGIN CRITICAL SECTION # # In order to avoid a race condition, we need to make sure that # the following code (from popping the queues up to the point # where we decide if we actually have any pending messages) is # atomic - otherwise new PDUs or EDUs might arrive in the # meantime, but not get sent because we hold the # transmission_loop_running flag. pending_pdus = self._pending_pdus # We can only include at most 50 PDUs per transactions pending_pdus, self._pending_pdus = pending_pdus[:50], pending_pdus[50:] pending_edus.extend(self._get_rr_edus(force_flush=False)) pending_presence = self._pending_presence self._pending_presence = {} if pending_presence: pending_edus.append( Edu( origin=self._server_name, destination=self._destination, edu_type="m.presence", content={ "push": [ format_user_presence_state( presence, self._clock.time_msec() ) for presence in pending_presence.values() ] }, ) ) pending_edus.extend( self._pop_pending_edus(MAX_EDUS_PER_TRANSACTION - len(pending_edus)) ) while ( len(pending_edus) < MAX_EDUS_PER_TRANSACTION and self._pending_edus_keyed ): _, val = self._pending_edus_keyed.popitem() pending_edus.append(val) if pending_pdus: logger.debug( "TX [%s] len(pending_pdus_by_dest[dest]) = %d", self._destination, len(pending_pdus), ) if not pending_pdus and not pending_edus: logger.debug("TX [%s] Nothing to send", self._destination) self._last_device_stream_id = device_stream_id return # if we've decided to send a transaction anyway, and we have room, we # may as well send any pending RRs if len(pending_edus) < MAX_EDUS_PER_TRANSACTION: pending_edus.extend(self._get_rr_edus(force_flush=True)) # END CRITICAL SECTION success = yield self._transaction_manager.send_new_transaction( self._destination, pending_pdus, pending_edus ) if success: sent_transactions_counter.inc() sent_edus_counter.inc(len(pending_edus)) for edu in pending_edus: sent_edus_by_type.labels(edu.edu_type).inc() # Remove the acknowledged device messages from the database # Only bother if we actually sent some device messages if to_device_edus: yield self._store.delete_device_msgs_for_remote( self._destination, device_stream_id ) # also mark the device updates as sent if device_update_edus: logger.info( "Marking as sent %r %r", self._destination, dev_list_id ) yield self._store.mark_as_sent_devices_by_remote( self._destination, dev_list_id ) self._last_device_stream_id = device_stream_id self._last_device_list_stream_id = dev_list_id else: break except NotRetryingDestination as e: logger.debug( "TX [%s] not ready for retry yet (next retry at %s) - " "dropping transaction for now", self._destination, datetime.datetime.fromtimestamp( (e.retry_last_ts + e.retry_interval) / 1000.0 ), ) except FederationDeniedError as e: logger.info(e) except HttpResponseException as e: logger.warning( "TX [%s] Received %d response to transaction: %s", self._destination, e.code, e, ) except RequestSendFailed as e: logger.warning( "TX [%s] Failed to send transaction: %s", self._destination, e ) for p, _ in pending_pdus: logger.info( "Failed to send event %s to %s", p.event_id, self._destination ) except Exception: logger.exception("TX [%s] Failed to send transaction", self._destination) for p, _ in pending_pdus: logger.info( "Failed to send event %s to %s", p.event_id, self._destination ) finally: # We want to be *very* sure we clear this after we stop processing self.transmission_loop_running = False def _get_rr_edus(self, force_flush): if not self._pending_rrs: return if not force_flush and not self._rrs_pending_flush: # not yet time for this lot return edu = Edu( origin=self._server_name, destination=self._destination, edu_type="m.receipt", content=self._pending_rrs, ) self._pending_rrs = {} self._rrs_pending_flush = False yield edu def _pop_pending_edus(self, limit): pending_edus = self._pending_edus pending_edus, self._pending_edus = pending_edus[:limit], pending_edus[limit:] return pending_edus @defer.inlineCallbacks def _get_device_update_edus(self, limit): last_device_list = self._last_device_list_stream_id # Retrieve list of new device updates to send to the destination now_stream_id, results = yield self._store.get_devices_by_remote( self._destination, last_device_list, limit=limit ) edus = [ Edu( origin=self._server_name, destination=self._destination, edu_type="m.device_list_update", content=content, ) for content in results ] assert len(edus) <= limit, "get_devices_by_remote returned too many EDUs" return (edus, now_stream_id) @defer.inlineCallbacks def _get_to_device_message_edus(self, limit): last_device_stream_id = self._last_device_stream_id to_device_stream_id = self._store.get_to_device_stream_token() contents, stream_id = yield self._store.get_new_device_msgs_for_remote( self._destination, last_device_stream_id, to_device_stream_id, limit ) edus = [ Edu( origin=self._server_name, destination=self._destination, edu_type="m.direct_to_device", content=content, ) for content in contents ] return (edus, stream_id)