add suppport for persisting batched events over replication

synapse/handlers/message.py

@@ -56,6 +56,7 @@
 from synapse.logging.context import make_deferred_yieldable, run_in_background
 from synapse.metrics.background_process_metrics import run_as_background_process
 from synapse.replication.http.send_event import ReplicationSendEventRestServlet
+from synapse.replication.http.send_events import ReplicationSendEventsRestServlet
 from synapse.storage.databases.main.events import PartialStateConflictError
 from synapse.storage.databases.main.events_worker import EventRedactBehaviour
 from synapse.storage.state import StateFilter
@@ -494,6 +495,7 @@ def __init__(self, hs: "HomeServer"):
             self.membership_types_to_include_profile_data_in.add(Membership.INVITE)
 
         self.send_event = ReplicationSendEventRestServlet.make_client(hs)
+        self.send_events = ReplicationSendEventsRestServlet.make_client(hs)
 
         self.request_ratelimiter = hs.get_request_ratelimiter()
 
@@ -1370,7 +1372,7 @@ async def handle_create_room_events(
 
     async def _persist_events_batch(
         self,
-        requestor: Requester,
+        requester: Requester,
         events_and_ctx: List[Tuple[EventBase, EventContext]],
         ratelimit: bool = True,
     ) -> EventBase:
@@ -1386,8 +1388,31 @@ async def _persist_events_batch(
                     event, context
                 )
         try:
+            # If we're a worker we need to hit out to the master.
+            writer_instance = self._events_shard_config.get_instance(event.room_id)
+            if writer_instance != self._instance_name:
+                try:
+                    result = await self.send_events(
+                        instance_name=writer_instance,
+                        store=self.store,
+                        requester=requester,
+                        events_and_ctx=events_and_ctx,
+                        ratelimit=ratelimit,
+                    )
+                except SynapseError as e:
+                    if e.code == HTTPStatus.CONFLICT:
+                        raise PartialStateConflictError()
+                    raise
+                stream_id = result["stream_id"]
+
+                # If we newly persisted the event then we need to update its
+                # stream_ordering entry manually (as it was persisted on
+                # another worker).
+                event.internal_metadata.stream_ordering = stream_id
+                return event
+
             last_event = await self.persist_and_notify_batched_events(
-                requestor, events_and_ctx, ratelimit
+                requester, events_and_ctx, ratelimit
             )
         except Exception:
             # Ensure that we actually remove the entries in the push actions

synapse/replication/http/__init__.py

@@ -25,6 +25,7 @@
     push,
     register,
     send_event,
+    send_events,
     state,
     streams,
 )
@@ -43,6 +44,7 @@ def __init__(self, hs: "HomeServer"):
 
     def register_servlets(self, hs: "HomeServer") -> None:
         send_event.register_servlets(hs, self)
+        send_events.register_servlets(hs, self)
         federation.register_servlets(hs, self)
         presence.register_servlets(hs, self)
         membership.register_servlets(hs, self)

synapse/replication/http/send_events.py

@@ -0,0 +1,165 @@
+# Copyright 2022 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.
+
+import logging
+from typing import TYPE_CHECKING, List, Tuple
+
+from twisted.web.server import Request
+
+from synapse.api.room_versions import KNOWN_ROOM_VERSIONS
+from synapse.events import EventBase, make_event_from_dict
+from synapse.events.snapshot import EventContext
+from synapse.http.server import HttpServer
+from synapse.http.servlet import parse_json_object_from_request
+from synapse.replication.http._base import ReplicationEndpoint
+from synapse.types import JsonDict, Requester
+from synapse.util.metrics import Measure
+
+if TYPE_CHECKING:
+    from synapse.server import HomeServer
+    from synapse.storage.databases.main import DataStore
+
+logger = logging.getLogger(__name__)
+
+
+class ReplicationSendEventsRestServlet(ReplicationEndpoint):
+    """Handles batches of newly created events on workers, including persisting and
+    notifying.
+
+    The API looks like:
+
+        POST /_synapse/replication/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 .. },
+                "outlier": true|false,
+                "rejected_reason": ..,   // The event.rejected_reason field
+                "context": { .. serialized event context .. },
+                "requester": { .. serialized requester .. },
+                "ratelimit": true,
+            }]
+        }
+
+        200 OK
+
+        { "stream_id": 12345, "event_id": "$abcdef..." }
+
+    Responds with a 409 when a `PartialStateConflictError` is raised due to an event
+    context that needs to be recomputed due to the un-partial stating of a room.
+
+    """
+
+    NAME = "send_events"
+    PATH_ARGS = ()
+
+    def __init__(self, hs: "HomeServer"):
+        super().__init__(hs)
+
+        self.event_creation_handler = hs.get_event_creation_handler()
+        self.store = hs.get_datastores().main
+        self._storage_controllers = hs.get_storage_controllers()
+        self.clock = hs.get_clock()
+
+    @staticmethod
+    async def _serialize_payload(  # type: ignore[override]
+        store: "DataStore",
+        events_and_ctx: List[Tuple[EventBase, EventContext]],
+        requester: Requester,
+        ratelimit: bool,
+    ) -> JsonDict:
+        """
+        Args:
+            store
+            requester
+            events_and_ctx
+            ratelimit
+        """
+        serialized_events = []
+
+        for event, context in events_and_ctx:
+            serialized_context = await context.serialize(event, store)
+            serialized_event = {
+                "event": event.get_pdu_json(),
+                "room_version": event.room_version.identifier,
+                "event_format_version": event.format_version,
+                "internal_metadata": event.internal_metadata.get_dict(),
+                "outlier": event.internal_metadata.is_outlier(),
+                "rejected_reason": event.rejected_reason,
+                "context": serialized_context,
+                "requester": requester.serialize(),
+                "ratelimit": ratelimit,
+            }
+            serialized_events.append(serialized_event)
+
+        payload = {"events": serialized_events}
+
+        return payload
+
+    async def _handle_request(  # type: ignore[override]
+        self, request: Request
+    ) -> Tuple[int, JsonDict]:
+        with Measure(self.clock, "repl_send_events_parse"):
+            payload = parse_json_object_from_request(request)
+            events_and_ctx = []
+            events = payload["events"]
+
+            for event_payload in events:
+                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
+                )
+                event.internal_metadata.outlier = event_payload["outlier"]
+
+                requester = Requester.deserialize(
+                    self.store, event_payload["requester"]
+                )
+                context = EventContext.deserialize(
+                    self._storage_controllers, event_payload["context"]
+                )
+
+                ratelimit = event_payload["ratelimit"]
+                events_and_ctx.append((event, context))
+
+                logger.info(
+                    "Got batch of events to send, last ID of batch is: %s, sending into room: %s",
+                    event.event_id,
+                    event.room_id,
+                )
+
+            last_event = (
+                await self.event_creation_handler.persist_and_notify_batched_events(
+                    requester, events_and_ctx, ratelimit
+                )
+            )
+
+        return (
+            200,
+            {
+                "stream_id": last_event.internal_metadata.stream_ordering,
+                "event_id": last_event.event_id,
+            },
+        )
+
+
+def register_servlets(hs: "HomeServer", http_server: HttpServer) -> None:
+    ReplicationSendEventsRestServlet(hs).register(http_server)