diff --git a/changelog.d/10272.bugfix b/changelog.d/10272.bugfix new file mode 100644 index 000000000..3cefa0578 --- /dev/null +++ b/changelog.d/10272.bugfix @@ -0,0 +1 @@ +Handle inbound events from federation asynchronously. diff --git a/synapse/federation/federation_server.py b/synapse/federation/federation_server.py index 2b07f1852..1d050e54e 100644 --- a/synapse/federation/federation_server.py +++ b/synapse/federation/federation_server.py @@ -44,7 +44,7 @@ from synapse.api.errors import ( SynapseError, UnsupportedRoomVersionError, ) -from synapse.api.room_versions import KNOWN_ROOM_VERSIONS +from synapse.api.room_versions import KNOWN_ROOM_VERSIONS, RoomVersion from synapse.events import EventBase from synapse.federation.federation_base import FederationBase, event_from_pdu_json from synapse.federation.persistence import TransactionActions @@ -57,10 +57,12 @@ from synapse.logging.context import ( ) from synapse.logging.opentracing import log_kv, start_active_span_from_edu, trace from synapse.logging.utils import log_function +from synapse.metrics.background_process_metrics import wrap_as_background_process from synapse.replication.http.federation import ( ReplicationFederationSendEduRestServlet, ReplicationGetQueryRestServlet, ) +from synapse.storage.databases.main.lock import Lock from synapse.types import JsonDict from synapse.util import glob_to_regex, json_decoder, unwrapFirstError from synapse.util.async_helpers import Linearizer, concurrently_execute @@ -96,6 +98,11 @@ last_pdu_ts_metric = Gauge( ) +# The name of the lock to use when process events in a room received over +# federation. +_INBOUND_EVENT_HANDLING_LOCK_NAME = "federation_inbound_pdu" + + class FederationServer(FederationBase): def __init__(self, hs: "HomeServer"): super().__init__(hs) @@ -834,7 +841,94 @@ class FederationServer(FederationBase): except SynapseError as e: raise FederationError("ERROR", e.code, e.msg, affected=pdu.event_id) - await self.handler.on_receive_pdu(origin, pdu, sent_to_us_directly=True) + # Add the event to our staging area + await self.store.insert_received_event_to_staging(origin, pdu) + + # Try and acquire the processing lock for the room, if we get it start a + # background process for handling the events in the room. + lock = await self.store.try_acquire_lock( + _INBOUND_EVENT_HANDLING_LOCK_NAME, pdu.room_id + ) + if lock: + self._process_incoming_pdus_in_room_inner( + pdu.room_id, room_version, lock, origin, pdu + ) + + @wrap_as_background_process("_process_incoming_pdus_in_room_inner") + async def _process_incoming_pdus_in_room_inner( + self, + room_id: str, + room_version: RoomVersion, + lock: Lock, + latest_origin: str, + latest_event: EventBase, + ) -> None: + """Process events in the staging area for the given room. + + The latest_origin and latest_event args are the latest origin and event + received. + """ + + # The common path is for the event we just received be the only event in + # the room, so instead of pulling the event out of the DB and parsing + # the event we just pull out the next event ID and check if that matches. + next_origin, next_event_id = await self.store.get_next_staged_event_id_for_room( + room_id + ) + if next_origin == latest_origin and next_event_id == latest_event.event_id: + origin = latest_origin + event = latest_event + else: + next = await self.store.get_next_staged_event_for_room( + room_id, room_version + ) + if not next: + return + + origin, event = next + + # We loop round until there are no more events in the room in the + # staging area, or we fail to get the lock (which means another process + # has started processing). + while True: + async with lock: + try: + await self.handler.on_receive_pdu( + origin, event, sent_to_us_directly=True + ) + except FederationError as e: + # XXX: Ideally we'd inform the remote we failed to process + # the event, but we can't return an error in the transaction + # response (as we've already responded). + logger.warning("Error handling PDU %s: %s", event.event_id, e) + except Exception: + f = failure.Failure() + logger.error( + "Failed to handle PDU %s", + event.event_id, + exc_info=(f.type, f.value, f.getTracebackObject()), # type: ignore + ) + + await self.store.remove_received_event_from_staging( + origin, event.event_id + ) + + # We need to do this check outside the lock to avoid a race between + # a new event being inserted by another instance and it attempting + # to acquire the lock. + next = await self.store.get_next_staged_event_for_room( + room_id, room_version + ) + if not next: + break + + origin, event = next + + lock = await self.store.try_acquire_lock( + _INBOUND_EVENT_HANDLING_LOCK_NAME, room_id + ) + if not lock: + return def __str__(self) -> str: return "" % self.server_name diff --git a/synapse/storage/databases/main/event_federation.py b/synapse/storage/databases/main/event_federation.py index c0ea44555..f23f8c6ec 100644 --- a/synapse/storage/databases/main/event_federation.py +++ b/synapse/storage/databases/main/event_federation.py @@ -14,18 +14,20 @@ import itertools import logging from queue import Empty, PriorityQueue -from typing import Collection, Dict, Iterable, List, Set, Tuple +from typing import Collection, Dict, Iterable, List, Optional, Set, Tuple from synapse.api.constants import MAX_DEPTH from synapse.api.errors import StoreError -from synapse.events import EventBase +from synapse.api.room_versions import RoomVersion +from synapse.events import EventBase, make_event_from_dict from synapse.metrics.background_process_metrics import wrap_as_background_process -from synapse.storage._base import SQLBaseStore, make_in_list_sql_clause +from synapse.storage._base import SQLBaseStore, db_to_json, make_in_list_sql_clause from synapse.storage.database import DatabasePool, LoggingTransaction from synapse.storage.databases.main.events_worker import EventsWorkerStore from synapse.storage.databases.main.signatures import SignatureWorkerStore from synapse.storage.engines import PostgresEngine from synapse.storage.types import Cursor +from synapse.util import json_encoder from synapse.util.caches.descriptors import cached from synapse.util.caches.lrucache import LruCache from synapse.util.iterutils import batch_iter @@ -1044,6 +1046,107 @@ class EventFederationWorkerStore(EventsWorkerStore, SignatureWorkerStore, SQLBas _delete_old_forward_extrem_cache_txn, ) + async def insert_received_event_to_staging( + self, origin: str, event: EventBase + ) -> None: + """Insert a newly received event from federation into the staging area.""" + + # We use an upsert here to handle the case where we see the same event + # from the same server multiple times. + await self.db_pool.simple_upsert( + table="federation_inbound_events_staging", + keyvalues={ + "origin": origin, + "event_id": event.event_id, + }, + values={}, + insertion_values={ + "room_id": event.room_id, + "received_ts": self._clock.time_msec(), + "event_json": json_encoder.encode(event.get_dict()), + "internal_metadata": json_encoder.encode( + event.internal_metadata.get_dict() + ), + }, + desc="insert_received_event_to_staging", + ) + + async def remove_received_event_from_staging( + self, + origin: str, + event_id: str, + ) -> None: + """Remove the given event from the staging area""" + await self.db_pool.simple_delete( + table="federation_inbound_events_staging", + keyvalues={ + "origin": origin, + "event_id": event_id, + }, + desc="remove_received_event_from_staging", + ) + + async def get_next_staged_event_id_for_room( + self, + room_id: str, + ) -> Optional[Tuple[str, str]]: + """Get the next event ID in the staging area for the given room.""" + + def _get_next_staged_event_id_for_room_txn(txn): + sql = """ + SELECT origin, event_id + FROM federation_inbound_events_staging + WHERE room_id = ? + ORDER BY received_ts ASC + LIMIT 1 + """ + + txn.execute(sql, (room_id,)) + + return txn.fetchone() + + return await self.db_pool.runInteraction( + "get_next_staged_event_id_for_room", _get_next_staged_event_id_for_room_txn + ) + + async def get_next_staged_event_for_room( + self, + room_id: str, + room_version: RoomVersion, + ) -> Optional[Tuple[str, EventBase]]: + """Get the next event in the staging area for the given room.""" + + def _get_next_staged_event_for_room_txn(txn): + sql = """ + SELECT event_json, internal_metadata, origin + FROM federation_inbound_events_staging + WHERE room_id = ? + ORDER BY received_ts ASC + LIMIT 1 + """ + txn.execute(sql, (room_id,)) + + return txn.fetchone() + + row = await self.db_pool.runInteraction( + "get_next_staged_event_for_room", _get_next_staged_event_for_room_txn + ) + + if not row: + return None + + event_d = db_to_json(row[0]) + internal_metadata_d = db_to_json(row[1]) + origin = row[2] + + event = make_event_from_dict( + event_dict=event_d, + room_version=room_version, + internal_metadata_dict=internal_metadata_d, + ) + + return origin, event + class EventFederationStore(EventFederationWorkerStore): """Responsible for storing and serving up the various graphs associated diff --git a/synapse/storage/schema/main/delta/59/16federation_inbound_staging.sql b/synapse/storage/schema/main/delta/59/16federation_inbound_staging.sql new file mode 100644 index 000000000..43bc5c025 --- /dev/null +++ b/synapse/storage/schema/main/delta/59/16federation_inbound_staging.sql @@ -0,0 +1,32 @@ +/* Copyright 2021 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. + */ + + +-- A staging area for newly received events over federation. +-- +-- Note we may store the same event multiple times if it comes from different +-- servers; this is to handle the case if we get a redacted and non-redacted +-- versions of the event. +CREATE TABLE federation_inbound_events_staging ( + origin TEXT NOT NULL, + room_id TEXT NOT NULL, + event_id TEXT NOT NULL, + received_ts BIGINT NOT NULL, + event_json TEXT NOT NULL, + internal_metadata TEXT NOT NULL +); + +CREATE INDEX federation_inbound_events_staging_room ON federation_inbound_events_staging(room_id, received_ts); +CREATE UNIQUE INDEX federation_inbound_events_staging_instance_event ON federation_inbound_events_staging(origin, event_id); diff --git a/sytest-blacklist b/sytest-blacklist index de9986357..89c4e828f 100644 --- a/sytest-blacklist +++ b/sytest-blacklist @@ -41,3 +41,9 @@ We can't peek into rooms with invited history_visibility We can't peek into rooms with joined history_visibility Local users can peek by room alias Peeked rooms only turn up in the sync for the device who peeked them + + +# Blacklisted due to changes made in #10272 +Outbound federation will ignore a missing event with bad JSON for room version 6 +Backfilled events whose prev_events are in a different room do not allow cross-room back-pagination +Federation rejects inbound events where the prev_events cannot be found