From 05e8c70c059f8ebb066e029bc3aa3e0cefef1019 Mon Sep 17 00:00:00 2001 From: Jonathan de Jong Date: Wed, 14 Apr 2021 18:19:02 +0200 Subject: [PATCH] Experimental Federation Speedup (#9702) This basically speeds up federation by "squeezing" each individual dual database call (to destinations and destination_rooms), which previously happened per every event, into one call for an entire batch (100 max). Signed-off-by: Jonathan de Jong --- changelog.d/9702.misc | 1 + contrib/experiments/test_messaging.py | 42 +++--- synapse/federation/sender/__init__.py | 136 +++++++++++------- .../sender/per_destination_queue.py | 15 +- .../storage/databases/main/transactions.py | 28 ++-- 5 files changed, 127 insertions(+), 95 deletions(-) create mode 100644 changelog.d/9702.misc diff --git a/changelog.d/9702.misc b/changelog.d/9702.misc new file mode 100644 index 0000000000..c6e63450a9 --- /dev/null +++ b/changelog.d/9702.misc @@ -0,0 +1 @@ +Speed up federation transmission by using fewer database calls. Contributed by @ShadowJonathan. diff --git a/contrib/experiments/test_messaging.py b/contrib/experiments/test_messaging.py index 31b8a68225..5dd172052b 100644 --- a/contrib/experiments/test_messaging.py +++ b/contrib/experiments/test_messaging.py @@ -224,14 +224,16 @@ class HomeServer(ReplicationHandler): destinations = yield self.get_servers_for_context(room_name) try: - yield self.replication_layer.send_pdu( - Pdu.create_new( - context=room_name, - pdu_type="sy.room.message", - content={"sender": sender, "body": body}, - origin=self.server_name, - destinations=destinations, - ) + yield self.replication_layer.send_pdus( + [ + Pdu.create_new( + context=room_name, + pdu_type="sy.room.message", + content={"sender": sender, "body": body}, + origin=self.server_name, + destinations=destinations, + ) + ] ) except Exception as e: logger.exception(e) @@ -253,7 +255,7 @@ class HomeServer(ReplicationHandler): origin=self.server_name, destinations=destinations, ) - yield self.replication_layer.send_pdu(pdu) + yield self.replication_layer.send_pdus([pdu]) except Exception as e: logger.exception(e) @@ -265,16 +267,18 @@ class HomeServer(ReplicationHandler): destinations = yield self.get_servers_for_context(room_name) try: - yield self.replication_layer.send_pdu( - Pdu.create_new( - context=room_name, - is_state=True, - pdu_type="sy.room.member", - state_key=invitee, - content={"membership": "invite"}, - origin=self.server_name, - destinations=destinations, - ) + yield self.replication_layer.send_pdus( + [ + Pdu.create_new( + context=room_name, + is_state=True, + pdu_type="sy.room.member", + state_key=invitee, + content={"membership": "invite"}, + origin=self.server_name, + destinations=destinations, + ) + ] ) except Exception as e: logger.exception(e) diff --git a/synapse/federation/sender/__init__.py b/synapse/federation/sender/__init__.py index 155161685d..952ad39f8c 100644 --- a/synapse/federation/sender/__init__.py +++ b/synapse/federation/sender/__init__.py @@ -18,8 +18,6 @@ from typing import TYPE_CHECKING, Dict, Hashable, Iterable, List, Optional, Set, from prometheus_client import Counter -from twisted.internet import defer - import synapse.metrics from synapse.api.presence import UserPresenceState from synapse.events import EventBase @@ -27,11 +25,7 @@ from synapse.federation.sender.per_destination_queue import PerDestinationQueue from synapse.federation.sender.transaction_manager import TransactionManager from synapse.federation.units import Edu from synapse.handlers.presence import get_interested_remotes -from synapse.logging.context import ( - make_deferred_yieldable, - preserve_fn, - run_in_background, -) +from synapse.logging.context import preserve_fn from synapse.metrics import ( LaterGauge, event_processing_loop_counter, @@ -39,7 +33,7 @@ from synapse.metrics import ( events_processed_counter, ) from synapse.metrics.background_process_metrics import run_as_background_process -from synapse.types import JsonDict, ReadReceipt, RoomStreamToken +from synapse.types import Collection, JsonDict, ReadReceipt, RoomStreamToken from synapse.util.metrics import Measure, measure_func if TYPE_CHECKING: @@ -276,15 +270,27 @@ class FederationSender(AbstractFederationSender): if not events and next_token >= self._last_poked_id: break - async def handle_event(event: EventBase) -> None: + async def get_destinations_for_event( + event: EventBase, + ) -> Collection[str]: + """Computes the destinations to which this event must be sent. + + This returns an empty tuple when there are no destinations to send to, + or if this event is not from this homeserver and it is not sending + it on behalf of another server. + + Will also filter out destinations which this sender is not responsible for, + if multiple federation senders exist. + """ + # 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.sender) if not is_mine and send_on_behalf_of is None: - return + return () if not event.internal_metadata.should_proactively_send(): - return + return () destinations = None # type: Optional[Set[str]] if not event.prev_event_ids(): @@ -319,7 +325,7 @@ class FederationSender(AbstractFederationSender): "Failed to calculate hosts in room for event: %s", event.event_id, ) - return + return () destinations = { d @@ -329,17 +335,15 @@ class FederationSender(AbstractFederationSender): ) } + destinations.discard(self.server_name) + 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) - if destinations: - await self._send_pdu(event, destinations) - now = self.clock.time_msec() ts = await self.store.get_received_ts(event.event_id) @@ -347,24 +351,29 @@ class FederationSender(AbstractFederationSender): "federation_sender" ).observe((now - ts) / 1000) - async def handle_room_events(events: Iterable[EventBase]) -> None: - with Measure(self.clock, "handle_room_events"): - for event in events: - await handle_event(event) + return destinations + return () - events_by_room = {} # type: Dict[str, List[EventBase]] - for event in events: - events_by_room.setdefault(event.room_id, []).append(event) + async def get_federatable_events_and_destinations( + events: Iterable[EventBase], + ) -> List[Tuple[EventBase, Collection[str]]]: + with Measure(self.clock, "get_destinations_for_events"): + # Fetch federation destinations per event, + # skip if get_destinations_for_event returns an empty collection, + # return list of event->destinations pairs. + return [ + (event, dests) + for (event, dests) in [ + (event, await get_destinations_for_event(event)) + for event in events + ] + if dests + ] - await make_deferred_yieldable( - defer.gatherResults( - [ - run_in_background(handle_room_events, evs) - for evs in events_by_room.values() - ], - consumeErrors=True, - ) - ) + events_and_dests = await get_federatable_events_and_destinations(events) + + # Send corresponding events to each destination queue + await self._distribute_events(events_and_dests) await self.store.update_federation_out_pos("events", next_token) @@ -382,7 +391,7 @@ class FederationSender(AbstractFederationSender): events_processed_counter.inc(len(events)) event_processing_loop_room_count.labels("federation_sender").inc( - len(events_by_room) + len({event.room_id for event in events}) ) event_processing_loop_counter.labels("federation_sender").inc() @@ -394,34 +403,53 @@ class FederationSender(AbstractFederationSender): finally: self._is_processing = False - async def _send_pdu(self, pdu: EventBase, destinations: Iterable[str]) -> None: - # 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. + async def _distribute_events( + self, + events_and_dests: Iterable[Tuple[EventBase, Collection[str]]], + ) -> None: + """Distribute events to the respective per_destination queues. - destinations = set(destinations) - destinations.discard(self.server_name) - logger.debug("Sending to: %s", str(destinations)) + Also persists last-seen per-room stream_ordering to 'destination_rooms'. - if not destinations: - return + Args: + events_and_dests: A list of tuples, which are (event: EventBase, destinations: Collection[str]). + Every event is paired with its intended destinations (in federation). + """ + # Tuples of room_id + destination to their max-seen stream_ordering + room_with_dest_stream_ordering = {} # type: Dict[Tuple[str, str], int] - sent_pdus_destination_dist_total.inc(len(destinations)) - sent_pdus_destination_dist_count.inc() + # List of events to send to each destination + events_by_dest = {} # type: Dict[str, List[EventBase]] - assert pdu.internal_metadata.stream_ordering + # For each event-destinations pair... + for event, destinations in events_and_dests: - # track the fact that we have a PDU for these destinations, - # to allow us to perform catch-up later on if the remote is unreachable - # for a while. - await self.store.store_destination_rooms_entries( - destinations, - pdu.room_id, - pdu.internal_metadata.stream_ordering, + # (we got this from the database, it's filled) + assert event.internal_metadata.stream_ordering + + sent_pdus_destination_dist_total.inc(len(destinations)) + sent_pdus_destination_dist_count.inc() + + # ...iterate over those destinations.. + for destination in destinations: + # ...update their stream-ordering... + room_with_dest_stream_ordering[(event.room_id, destination)] = max( + event.internal_metadata.stream_ordering, + room_with_dest_stream_ordering.get((event.room_id, destination), 0), + ) + + # ...and add the event to each destination queue. + events_by_dest.setdefault(destination, []).append(event) + + # Bulk-store destination_rooms stream_ids + await self.store.bulk_store_destination_rooms_entries( + room_with_dest_stream_ordering ) - for destination in destinations: - self._get_per_destination_queue(destination).send_pdu(pdu) + for destination, pdus in events_by_dest.items(): + logger.debug("Sending %d pdus to %s", len(pdus), destination) + + self._get_per_destination_queue(destination).send_pdus(pdus) async def send_read_receipt(self, receipt: ReadReceipt) -> None: """Send a RR to any other servers in the room diff --git a/synapse/federation/sender/per_destination_queue.py b/synapse/federation/sender/per_destination_queue.py index 3b053ebcfb..3bb66bce32 100644 --- a/synapse/federation/sender/per_destination_queue.py +++ b/synapse/federation/sender/per_destination_queue.py @@ -154,19 +154,22 @@ class PerDestinationQueue: + len(self._pending_edus_keyed) ) - def send_pdu(self, pdu: EventBase) -> None: - """Add a PDU to the queue, and start the transmission loop if necessary + def send_pdus(self, pdus: Iterable[EventBase]) -> None: + """Add PDUs to the queue, and start the transmission loop if necessary Args: - pdu: pdu to send + pdus: pdus to send """ if not self._catching_up or self._last_successful_stream_ordering is None: # only enqueue the PDU if we are not catching up (False) or do not # yet know if we have anything to catch up (None) - self._pending_pdus.append(pdu) + self._pending_pdus.extend(pdus) else: - assert pdu.internal_metadata.stream_ordering - self._catchup_last_skipped = pdu.internal_metadata.stream_ordering + self._catchup_last_skipped = max( + pdu.internal_metadata.stream_ordering + for pdu in pdus + if pdu.internal_metadata.stream_ordering is not None + ) self.attempt_new_transaction() diff --git a/synapse/storage/databases/main/transactions.py b/synapse/storage/databases/main/transactions.py index 82335e7a9d..b28ca61f80 100644 --- a/synapse/storage/databases/main/transactions.py +++ b/synapse/storage/databases/main/transactions.py @@ -14,7 +14,7 @@ import logging from collections import namedtuple -from typing import Iterable, List, Optional, Tuple +from typing import Dict, List, Optional, Tuple from canonicaljson import encode_canonical_json @@ -295,37 +295,33 @@ class TransactionStore(TransactionWorkerStore): }, ) - async def store_destination_rooms_entries( - self, - destinations: Iterable[str], - room_id: str, - stream_ordering: int, - ) -> None: + async def bulk_store_destination_rooms_entries( + self, room_and_destination_to_ordering: Dict[Tuple[str, str], int] + ): """ - Updates or creates `destination_rooms` entries in batch for a single event. + Updates or creates `destination_rooms` entries for a number of events. Args: - destinations: list of destinations - room_id: the room_id of the event - stream_ordering: the stream_ordering of the event + room_and_destination_to_ordering: A mapping of (room, destination) -> stream_id """ await self.db_pool.simple_upsert_many( table="destinations", key_names=("destination",), - key_values=[(d,) for d in destinations], + key_values={(d,) for _, d in room_and_destination_to_ordering.keys()}, value_names=[], value_values=[], desc="store_destination_rooms_entries_dests", ) - rows = [(destination, room_id) for destination in destinations] await self.db_pool.simple_upsert_many( table="destination_rooms", - key_names=("destination", "room_id"), - key_values=rows, + key_names=("room_id", "destination"), + key_values=list(room_and_destination_to_ordering.keys()), value_names=["stream_ordering"], - value_values=[(stream_ordering,)] * len(rows), + value_values=[ + (stream_id,) for stream_id in room_and_destination_to_ordering.values() + ], desc="store_destination_rooms_entries_rooms", )