# -*- coding: utf-8 -*- # Copyright 2014-2016 OpenMarket 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 six import itervalues from prometheus_client import Counter from twisted.internet import defer import synapse.metrics from synapse.api.errors import FederationDeniedError, HttpResponseException from synapse.handlers.presence import format_user_presence_state, get_interested_remotes from synapse.metrics import ( LaterGauge, event_processing_loop_counter, event_processing_loop_room_count, events_processed_counter, sent_edus_counter, sent_transactions_counter, ) from synapse.metrics.background_process_metrics import run_as_background_process from synapse.util import logcontext from synapse.util.metrics import measure_func from synapse.util.retryutils import NotRetryingDestination, get_retry_limiter from .persistence import TransactionActions from .units import Edu, Transaction logger = logging.getLogger(__name__) sent_pdus_destination_dist_count = Counter( "synapse_federation_client_sent_pdu_destinations:count", "" ) sent_pdus_destination_dist_total = Counter( "synapse_federation_client_sent_pdu_destinations:total", "" ) class TransactionQueue(object): """This class makes sure we only have one transaction in flight at a time for a given destination. It batches pending PDUs into single transactions. """ def __init__(self, hs): self.hs = hs self.server_name = hs.hostname self.store = hs.get_datastore() self.state = hs.get_state_handler() self.transaction_actions = TransactionActions(self.store) self.transport_layer = hs.get_federation_transport_client() self.clock = hs.get_clock() self.is_mine_id = hs.is_mine_id # Is a mapping from destinations -> deferreds. Used to keep track # of which destinations have transactions in flight and when they are # done self.pending_transactions = {} LaterGauge( "synapse_federation_transaction_queue_pending_destinations", "", [], lambda: len(self.pending_transactions), ) # Is a mapping from destination -> list of # tuple(pending pdus, deferred, order) self.pending_pdus_by_dest = pdus = {} # destination -> list of tuple(edu, deferred) self.pending_edus_by_dest = edus = {} # Map of user_id -> UserPresenceState for all the pending presence # to be sent out by user_id. Entries here get processed and put in # pending_presence_by_dest self.pending_presence = {} # Map of destination -> user_id -> UserPresenceState of pending presence # to be sent to each destinations self.pending_presence_by_dest = presence = {} # 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 destination -> (edu_type, key) -> Edu self.pending_edus_keyed_by_dest = edus_keyed = {} LaterGauge( "synapse_federation_transaction_queue_pending_pdus", "", [], lambda: sum(map(len, pdus.values())), ) LaterGauge( "synapse_federation_transaction_queue_pending_edus", "", [], lambda: ( sum(map(len, edus.values())) + sum(map(len, presence.values())) + sum(map(len, edus_keyed.values())) ), ) # destination -> stream_id of last successfully sent to-device message. # NB: may be a long or an int. self.last_device_stream_id_by_dest = {} # destination -> stream_id of last successfully sent device list # update. self.last_device_list_stream_id_by_dest = {} # HACK to get unique tx id self._next_txn_id = int(self.clock.time_msec()) self._order = 1 self._is_processing = False self._last_poked_id = -1 self._processing_pending_presence = False def notify_new_events(self, current_id): """This gets called when we have some new events we might want to send out to other servers. """ self._last_poked_id = max(current_id, self._last_poked_id) if self._is_processing: return # fire off a processing loop in the background run_as_background_process( "process_event_queue_for_federation", self._process_event_queue_loop, ) @defer.inlineCallbacks def _process_event_queue_loop(self): try: self._is_processing = True while True: last_token = yield self.store.get_federation_out_pos("events") next_token, events = yield self.store.get_all_new_events_stream( last_token, self._last_poked_id, limit=100, ) logger.debug("Handling %s -> %s", last_token, next_token) if not events and next_token >= self._last_poked_id: break @defer.inlineCallbacks def handle_event(event): # Only send events for this server. send_on_behalf_of = event.internal_metadata.get_send_on_behalf_of() is_mine = self.is_mine_id(event.event_id) if not is_mine and send_on_behalf_of is None: return try: # Get the state from before the event. # We need to make sure that this is the state from before # the event and not from after it. # Otherwise if the last member on a server in a room is # banned then it won't receive the event because it won't # be in the room after the ban. destinations = yield self.state.get_current_hosts_in_room( event.room_id, latest_event_ids=[ prev_id for prev_id, _ in event.prev_events ], ) except Exception: logger.exception( "Failed to calculate hosts in room for event: %s", event.event_id, ) return destinations = set(destinations) if send_on_behalf_of is not None: # If we are sending the event on behalf of another server # then it already has the event and there is no reason to # send the event to it. destinations.discard(send_on_behalf_of) logger.debug("Sending %s to %r", event, destinations) self._send_pdu(event, destinations) @defer.inlineCallbacks def handle_room_events(events): for event in events: yield handle_event(event) events_by_room = {} for event in events: events_by_room.setdefault(event.room_id, []).append(event) yield logcontext.make_deferred_yieldable(defer.gatherResults( [ logcontext.run_in_background(handle_room_events, evs) for evs in itervalues(events_by_room) ], consumeErrors=True )) yield self.store.update_federation_out_pos( "events", next_token ) if events: now = self.clock.time_msec() ts = yield self.store.get_received_ts(events[-1].event_id) synapse.metrics.event_processing_lag.labels( "federation_sender").set(now - ts) synapse.metrics.event_processing_last_ts.labels( "federation_sender").set(ts) events_processed_counter.inc(len(events)) event_processing_loop_room_count.labels( "federation_sender" ).inc(len(events_by_room)) event_processing_loop_counter.labels("federation_sender").inc() synapse.metrics.event_processing_positions.labels( "federation_sender").set(next_token) finally: self._is_processing = False def _send_pdu(self, pdu, destinations): # We loop through all destinations to see whether we already have # a transaction in progress. If we do, stick it in the pending_pdus # table and we'll get back to it later. order = self._order self._order += 1 destinations = set(destinations) destinations.discard(self.server_name) logger.debug("Sending to: %s", str(destinations)) if not destinations: return sent_pdus_destination_dist_total.inc(len(destinations)) sent_pdus_destination_dist_count.inc() for destination in destinations: self.pending_pdus_by_dest.setdefault(destination, []).append( (pdu, order) ) self._attempt_new_transaction(destination) @logcontext.preserve_fn # the caller should not yield on this @defer.inlineCallbacks def send_presence(self, states): """Send the new presence states to the appropriate destinations. This actually queues up the presence states ready for sending and triggers a background task to process them and send out the transactions. Args: states (list(UserPresenceState)) """ if not self.hs.config.use_presence: # No-op if presence is disabled. return # First we queue up the new presence by user ID, so multiple presence # updates in quick successtion are correctly handled # We only want to send presence for our own users, so lets always just # filter here just in case. self.pending_presence.update({ state.user_id: state for state in states if self.is_mine_id(state.user_id) }) # We then handle the new pending presence in batches, first figuring # out the destinations we need to send each state to and then poking it # to attempt a new transaction. We linearize this so that we don't # accidentally mess up the ordering and send multiple presence updates # in the wrong order if self._processing_pending_presence: return self._processing_pending_presence = True try: while True: states_map = self.pending_presence self.pending_presence = {} if not states_map: break yield self._process_presence_inner(list(states_map.values())) except Exception: logger.exception("Error sending presence states to servers") finally: self._processing_pending_presence = False @measure_func("txnqueue._process_presence") @defer.inlineCallbacks def _process_presence_inner(self, states): """Given a list of states populate self.pending_presence_by_dest and poke to send a new transaction to each destination Args: states (list(UserPresenceState)) """ hosts_and_states = yield get_interested_remotes(self.store, states, self.state) for destinations, states in hosts_and_states: for destination in destinations: if destination == self.server_name: continue self.pending_presence_by_dest.setdefault( destination, {} ).update({ state.user_id: state for state in states }) self._attempt_new_transaction(destination) def send_edu(self, destination, edu_type, content, key=None): edu = Edu( origin=self.server_name, destination=destination, edu_type=edu_type, content=content, ) if destination == self.server_name: logger.info("Not sending EDU to ourselves") return sent_edus_counter.inc() if key: self.pending_edus_keyed_by_dest.setdefault( destination, {} )[(edu.edu_type, key)] = edu else: self.pending_edus_by_dest.setdefault(destination, []).append(edu) self._attempt_new_transaction(destination) def send_device_messages(self, destination): if destination == self.server_name: logger.info("Not sending device update to ourselves") return self._attempt_new_transaction(destination) def get_current_token(self): return 0 def _attempt_new_transaction(self, destination): """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. Args: destination (str): Returns: None """ # list of (pending_pdu, deferred, order) if destination in self.pending_transactions: # XXX: pending_transactions can get stuck on by a never-ending # request at which point pending_pdus_by_dest just keeps growing. # we need application-layer timeouts of some flavour of these # requests logger.debug( "TX [%s] Transaction already in progress", destination ) return logger.debug("TX [%s] Starting transaction loop", destination) run_as_background_process( "federation_transaction_transmission_loop", self._transaction_transmission_loop, destination, ) @defer.inlineCallbacks def _transaction_transmission_loop(self, destination): pending_pdus = [] try: self.pending_transactions[destination] = 1 # 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(destination, self.clock, self.store) pending_pdus = [] while True: device_message_edus, device_stream_id, dev_list_id = ( yield self._get_new_device_messages(destination) ) # 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 # pending_transactions flag. pending_pdus = self.pending_pdus_by_dest.pop(destination, []) # We can only include at most 50 PDUs per transactions pending_pdus, leftover_pdus = pending_pdus[:50], pending_pdus[50:] if leftover_pdus: self.pending_pdus_by_dest[destination] = leftover_pdus pending_edus = self.pending_edus_by_dest.pop(destination, []) # We can only include at most 100 EDUs per transactions pending_edus, leftover_edus = pending_edus[:100], pending_edus[100:] if leftover_edus: self.pending_edus_by_dest[destination] = leftover_edus pending_presence = self.pending_presence_by_dest.pop(destination, {}) pending_edus.extend( self.pending_edus_keyed_by_dest.pop(destination, {}).values() ) pending_edus.extend(device_message_edus) if pending_presence: pending_edus.append( Edu( origin=self.server_name, destination=destination, edu_type="m.presence", content={ "push": [ format_user_presence_state( presence, self.clock.time_msec() ) for presence in pending_presence.values() ] }, ) ) if pending_pdus: logger.debug("TX [%s] len(pending_pdus_by_dest[dest]) = %d", destination, len(pending_pdus)) if not pending_pdus and not pending_edus: logger.debug("TX [%s] Nothing to send", destination) self.last_device_stream_id_by_dest[destination] = ( device_stream_id ) return # END CRITICAL SECTION success = yield self._send_new_transaction( destination, pending_pdus, pending_edus, ) if success: sent_transactions_counter.inc() # Remove the acknowledged device messages from the database # Only bother if we actually sent some device messages if device_message_edus: yield self.store.delete_device_msgs_for_remote( destination, device_stream_id ) logger.info("Marking as sent %r %r", destination, dev_list_id) yield self.store.mark_as_sent_devices_by_remote( destination, dev_list_id ) self.last_device_stream_id_by_dest[destination] = device_stream_id self.last_device_list_stream_id_by_dest[destination] = 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", destination, datetime.datetime.fromtimestamp( (e.retry_last_ts + e.retry_interval) / 1000.0 ), ) except FederationDeniedError as e: logger.info(e) except Exception as e: logger.warn( "TX [%s] Failed to send transaction: %s", destination, e, ) for p, _ in pending_pdus: logger.info("Failed to send event %s to %s", p.event_id, destination) finally: # We want to be *very* sure we delete this after we stop processing self.pending_transactions.pop(destination, None) @defer.inlineCallbacks def _get_new_device_messages(self, destination): last_device_stream_id = self.last_device_stream_id_by_dest.get(destination, 0) to_device_stream_id = self.store.get_to_device_stream_token() contents, stream_id = yield self.store.get_new_device_msgs_for_remote( destination, last_device_stream_id, to_device_stream_id ) edus = [ Edu( origin=self.server_name, destination=destination, edu_type="m.direct_to_device", content=content, ) for content in contents ] last_device_list = self.last_device_list_stream_id_by_dest.get(destination, 0) now_stream_id, results = yield self.store.get_devices_by_remote( destination, last_device_list ) edus.extend( Edu( origin=self.server_name, destination=destination, edu_type="m.device_list_update", content=content, ) for content in results ) defer.returnValue((edus, stream_id, now_stream_id)) @measure_func("_send_new_transaction") @defer.inlineCallbacks def _send_new_transaction(self, destination, pending_pdus, pending_edus): # Sort based on the order field pending_pdus.sort(key=lambda t: t[1]) pdus = [x[0] for x in pending_pdus] edus = pending_edus success = True logger.debug("TX [%s] _attempt_new_transaction", destination) txn_id = str(self._next_txn_id) logger.debug( "TX [%s] {%s} Attempting new transaction" " (pdus: %d, edus: %d)", destination, txn_id, len(pdus), len(edus), ) logger.debug("TX [%s] Persisting transaction...", destination) transaction = Transaction.create_new( origin_server_ts=int(self.clock.time_msec()), transaction_id=txn_id, origin=self.server_name, destination=destination, pdus=pdus, edus=edus, ) self._next_txn_id += 1 yield self.transaction_actions.prepare_to_send(transaction) logger.debug("TX [%s] Persisted transaction", destination) logger.info( "TX [%s] {%s} Sending transaction [%s]," " (PDUs: %d, EDUs: %d)", destination, txn_id, transaction.transaction_id, len(pdus), len(edus), ) # Actually send the transaction # FIXME (erikj): This is a bit of a hack to make the Pdu age # keys work def json_data_cb(): data = transaction.get_dict() now = int(self.clock.time_msec()) if "pdus" in data: for p in data["pdus"]: if "age_ts" in p: unsigned = p.setdefault("unsigned", {}) unsigned["age"] = now - int(p["age_ts"]) del p["age_ts"] return data try: response = yield self.transport_layer.send_transaction( transaction, json_data_cb ) code = 200 if response: for e_id, r in response.get("pdus", {}).items(): if "error" in r: logger.warn( "Transaction returned error for %s: %s", e_id, r, ) except HttpResponseException as e: code = e.code response = e.response if e.code in (401, 404, 429) or 500 <= e.code: logger.info( "TX [%s] {%s} got %d response", destination, txn_id, code ) raise e logger.info( "TX [%s] {%s} got %d response", destination, txn_id, code ) logger.debug("TX [%s] Sent transaction", destination) logger.debug("TX [%s] Marking as delivered...", destination) yield self.transaction_actions.delivered( transaction, code, response ) logger.debug("TX [%s] Marked as delivered", destination) if code != 200: for p in pdus: logger.info( "Failed to send event %s to %s", p.event_id, destination ) success = False defer.returnValue(success)