forked-synapse/synapse/replication/http/federation.py
Erik Johnston 1531b214fc
Add ability to wait for replication streams (#7542)
The idea here is that if an instance persists an event via the replication HTTP API it can return before we receive that event over replication, which can lead to races where code assumes that persisting an event immediately updates various caches (e.g. current state of the room).

Most of Synapse doesn't hit such races, so we don't do the waiting automagically, instead we do so where necessary to avoid unnecessary delays. We may decide to change our minds here if it turns out there are a lot of subtle races going on.

People probably want to look at this commit by commit.
2020-05-22 14:21:54 +01:00

292 lines
8.8 KiB
Python

# -*- coding: utf-8 -*-
# Copyright 2018 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 logging
from twisted.internet import defer
from synapse.api.room_versions import KNOWN_ROOM_VERSIONS
from synapse.events import make_event_from_dict
from synapse.events.snapshot import EventContext
from synapse.http.servlet import parse_json_object_from_request
from synapse.replication.http._base import ReplicationEndpoint
from synapse.util.metrics import Measure
logger = logging.getLogger(__name__)
class ReplicationFederationSendEventsRestServlet(ReplicationEndpoint):
"""Handles events newly received from federation, including persisting and
notifying. Returns the maximum stream ID of the persisted events.
The API looks like:
POST /_synapse/replication/fed_send_events/:txn_id
{
"events": [{
"event": { .. serialized event .. },
"room_version": .., // "1", "2", "3", etc: the version of the room
// containing the event
"event_format_version": .., // 1,2,3 etc: the event format version
"internal_metadata": { .. serialized internal_metadata .. },
"rejected_reason": .., // The event.rejected_reason field
"context": { .. serialized event context .. },
}],
"backfilled": false
}
200 OK
{
"max_stream_id": 32443,
}
"""
NAME = "fed_send_events"
PATH_ARGS = ()
def __init__(self, hs):
super(ReplicationFederationSendEventsRestServlet, self).__init__(hs)
self.store = hs.get_datastore()
self.storage = hs.get_storage()
self.clock = hs.get_clock()
self.federation_handler = hs.get_handlers().federation_handler
@staticmethod
@defer.inlineCallbacks
def _serialize_payload(store, event_and_contexts, backfilled):
"""
Args:
store
event_and_contexts (list[tuple[FrozenEvent, EventContext]])
backfilled (bool): Whether or not the events are the result of
backfilling
"""
event_payloads = []
for event, context in event_and_contexts:
serialized_context = yield context.serialize(event, store)
event_payloads.append(
{
"event": event.get_pdu_json(),
"room_version": event.room_version.identifier,
"event_format_version": event.format_version,
"internal_metadata": event.internal_metadata.get_dict(),
"rejected_reason": event.rejected_reason,
"context": serialized_context,
}
)
payload = {"events": event_payloads, "backfilled": backfilled}
return payload
async def _handle_request(self, request):
with Measure(self.clock, "repl_fed_send_events_parse"):
content = parse_json_object_from_request(request)
backfilled = content["backfilled"]
event_payloads = content["events"]
event_and_contexts = []
for event_payload in event_payloads:
event_dict = event_payload["event"]
room_ver = KNOWN_ROOM_VERSIONS[event_payload["room_version"]]
internal_metadata = event_payload["internal_metadata"]
rejected_reason = event_payload["rejected_reason"]
event = make_event_from_dict(
event_dict, room_ver, internal_metadata, rejected_reason
)
context = EventContext.deserialize(
self.storage, event_payload["context"]
)
event_and_contexts.append((event, context))
logger.info("Got %d events from federation", len(event_and_contexts))
max_stream_id = await self.federation_handler.persist_events_and_notify(
event_and_contexts, backfilled
)
return 200, {"max_stream_id": max_stream_id}
class ReplicationFederationSendEduRestServlet(ReplicationEndpoint):
"""Handles EDUs newly received from federation, including persisting and
notifying.
Request format:
POST /_synapse/replication/fed_send_edu/:edu_type/:txn_id
{
"origin": ...,
"content: { ... }
}
"""
NAME = "fed_send_edu"
PATH_ARGS = ("edu_type",)
def __init__(self, hs):
super(ReplicationFederationSendEduRestServlet, self).__init__(hs)
self.store = hs.get_datastore()
self.clock = hs.get_clock()
self.registry = hs.get_federation_registry()
@staticmethod
def _serialize_payload(edu_type, origin, content):
return {"origin": origin, "content": content}
async def _handle_request(self, request, edu_type):
with Measure(self.clock, "repl_fed_send_edu_parse"):
content = parse_json_object_from_request(request)
origin = content["origin"]
edu_content = content["content"]
logger.info("Got %r edu from %s", edu_type, origin)
result = await self.registry.on_edu(edu_type, origin, edu_content)
return 200, result
class ReplicationGetQueryRestServlet(ReplicationEndpoint):
"""Handle responding to queries from federation.
Request format:
POST /_synapse/replication/fed_query/:query_type
{
"args": { ... }
}
"""
NAME = "fed_query"
PATH_ARGS = ("query_type",)
# This is a query, so let's not bother caching
CACHE = False
def __init__(self, hs):
super(ReplicationGetQueryRestServlet, self).__init__(hs)
self.store = hs.get_datastore()
self.clock = hs.get_clock()
self.registry = hs.get_federation_registry()
@staticmethod
def _serialize_payload(query_type, args):
"""
Args:
query_type (str)
args (dict): The arguments received for the given query type
"""
return {"args": args}
async def _handle_request(self, request, query_type):
with Measure(self.clock, "repl_fed_query_parse"):
content = parse_json_object_from_request(request)
args = content["args"]
logger.info("Got %r query", query_type)
result = await self.registry.on_query(query_type, args)
return 200, result
class ReplicationCleanRoomRestServlet(ReplicationEndpoint):
"""Called to clean up any data in DB for a given room, ready for the
server to join the room.
Request format:
POST /_synapse/replication/fed_cleanup_room/:room_id/:txn_id
{}
"""
NAME = "fed_cleanup_room"
PATH_ARGS = ("room_id",)
def __init__(self, hs):
super(ReplicationCleanRoomRestServlet, self).__init__(hs)
self.store = hs.get_datastore()
@staticmethod
def _serialize_payload(room_id, args):
"""
Args:
room_id (str)
"""
return {}
async def _handle_request(self, request, room_id):
await self.store.clean_room_for_join(room_id)
return 200, {}
class ReplicationStoreRoomOnInviteRestServlet(ReplicationEndpoint):
"""Called to clean up any data in DB for a given room, ready for the
server to join the room.
Request format:
POST /_synapse/replication/store_room_on_invite/:room_id/:txn_id
{
"room_version": "1",
}
"""
NAME = "store_room_on_invite"
PATH_ARGS = ("room_id",)
def __init__(self, hs):
super().__init__(hs)
self.store = hs.get_datastore()
@staticmethod
def _serialize_payload(room_id, room_version):
return {"room_version": room_version.identifier}
async def _handle_request(self, request, room_id):
content = parse_json_object_from_request(request)
room_version = KNOWN_ROOM_VERSIONS[content["room_version"]]
await self.store.maybe_store_room_on_invite(room_id, room_version)
return 200, {}
def register_servlets(hs, http_server):
ReplicationFederationSendEventsRestServlet(hs).register(http_server)
ReplicationFederationSendEduRestServlet(hs).register(http_server)
ReplicationGetQueryRestServlet(hs).register(http_server)
ReplicationCleanRoomRestServlet(hs).register(http_server)
ReplicationStoreRoomOnInviteRestServlet(hs).register(http_server)