Fix bug in sliding sync when using old DB. (#17398)

We don't necessarily have `instance_name` for old events (before we
support multiple event persisters). We treat those as if the
`instance_name` was "master".

---------

Co-authored-by: Eric Eastwood <eric.eastwood@beta.gouv.fr>

4 files changed, 31 insertions, 82 deletions

diff --git a/synapse/storage/databases/main/cache.py b/synapse/storage/databases/main/cache.py
index c6787faea0..2d6b75e47e 100644
--- a/synapse/storage/databases/main/cache.py
+++ b/synapse/storage/databases/main/cache.py
@@ -268,16 +268,12 @@ class CacheInvalidationWorkerStore(SQLBaseStore):
             self._curr_state_delta_stream_cache.entity_has_changed(data.room_id, token)  # type: ignore[attr-defined]
 
             if data.type == EventTypes.Member:
-                self.get_rooms_for_user_with_stream_ordering.invalidate(  # type: ignore[attr-defined]
-                    (data.state_key,)
-                )
                 self.get_rooms_for_user.invalidate((data.state_key,))  # type: ignore[attr-defined]
         elif row.type == EventsStreamAllStateRow.TypeId:
             assert isinstance(data, EventsStreamAllStateRow)
             # Similar to the above, but the entire caches are invalidated. This is
             # unfortunate for the membership caches, but should recover quickly.
             self._curr_state_delta_stream_cache.entity_has_changed(data.room_id, token)  # type: ignore[attr-defined]
-            self.get_rooms_for_user_with_stream_ordering.invalidate_all()  # type: ignore[attr-defined]
             self.get_rooms_for_user.invalidate_all()  # type: ignore[attr-defined]
         else:
             raise Exception("Unknown events stream row type %s" % (row.type,))
@@ -334,9 +330,6 @@ class CacheInvalidationWorkerStore(SQLBaseStore):
             self._attempt_to_invalidate_cache(
                 "get_invited_rooms_for_local_user", (state_key,)
             )
-            self._attempt_to_invalidate_cache(
-                "get_rooms_for_user_with_stream_ordering", (state_key,)
-            )
             self._attempt_to_invalidate_cache("get_rooms_for_user", (state_key,))
 
             self._attempt_to_invalidate_cache(
@@ -399,9 +392,6 @@ class CacheInvalidationWorkerStore(SQLBaseStore):
         self._attempt_to_invalidate_cache("get_thread_id", None)
         self._attempt_to_invalidate_cache("get_thread_id_for_receipts", None)
         self._attempt_to_invalidate_cache("get_invited_rooms_for_local_user", None)
-        self._attempt_to_invalidate_cache(
-            "get_rooms_for_user_with_stream_ordering", None
-        )
         self._attempt_to_invalidate_cache("get_rooms_for_user", None)
         self._attempt_to_invalidate_cache("did_forget", None)
         self._attempt_to_invalidate_cache("get_forgotten_rooms_for_user", None)
diff --git a/synapse/storage/databases/main/events_worker.py b/synapse/storage/databases/main/events_worker.py
index a5acea8c3b..4d4877c4c3 100644
--- a/synapse/storage/databases/main/events_worker.py
+++ b/synapse/storage/databases/main/events_worker.py
@@ -1457,7 +1457,8 @@ class EventsWorkerStore(SQLBaseStore):
                 event_dict[event_id] = _EventRow(
                     event_id=event_id,
                     stream_ordering=row[1],
-                    instance_name=row[2],
+                    # If instance_name is null we default to "master"
+                    instance_name=row[2] or "master",
                     internal_metadata=row[3],
                     json=row[4],
                     format_version=row[5],
diff --git a/synapse/storage/databases/main/roommember.py b/synapse/storage/databases/main/roommember.py
index d8b54dc4e3..5d2fd08495 100644
--- a/synapse/storage/databases/main/roommember.py
+++ b/synapse/storage/databases/main/roommember.py
@@ -50,12 +50,7 @@ from synapse.storage.database import (
 from synapse.storage.databases.main.cache import CacheInvalidationWorkerStore
 from synapse.storage.databases.main.events_worker import EventsWorkerStore
 from synapse.storage.engines import Sqlite3Engine
-from synapse.storage.roommember import (
-    GetRoomsForUserWithStreamOrdering,
-    MemberSummary,
-    ProfileInfo,
-    RoomsForUser,
-)
+from synapse.storage.roommember import MemberSummary, ProfileInfo, RoomsForUser
 from synapse.types import (
     JsonDict,
     PersistedEventPosition,
@@ -494,7 +489,11 @@ class RoomMemberWorkerStore(EventsWorkerStore, CacheInvalidationWorkerStore):
                 sender=sender,
                 membership=membership,
                 event_id=event_id,
-                event_pos=PersistedEventPosition(instance_name, stream_ordering),
+                event_pos=PersistedEventPosition(
+                    # If instance_name is null we default to "master"
+                    instance_name or "master",
+                    stream_ordering,
+                ),
                 room_version_id=room_version,
             )
             for room_id, sender, membership, event_id, instance_name, stream_ordering, room_version in txn
@@ -606,53 +605,6 @@ class RoomMemberWorkerStore(EventsWorkerStore, CacheInvalidationWorkerStore):
 
         return results
 
-    @cached(max_entries=500000, iterable=True)
-    async def get_rooms_for_user_with_stream_ordering(
-        self, user_id: str
-    ) -> FrozenSet[GetRoomsForUserWithStreamOrdering]:
-        """Returns a set of room_ids the user is currently joined to.
-
-        If a remote user only returns rooms this server is currently
-        participating in.
-
-        Args:
-            user_id
-
-        Returns:
-            Returns the rooms the user is in currently, along with the stream
-            ordering of the most recent join for that user and room, along with
-            the room version of the room.
-        """
-        return await self.db_pool.runInteraction(
-            "get_rooms_for_user_with_stream_ordering",
-            self._get_rooms_for_user_with_stream_ordering_txn,
-            user_id,
-        )
-
-    def _get_rooms_for_user_with_stream_ordering_txn(
-        self, txn: LoggingTransaction, user_id: str
-    ) -> FrozenSet[GetRoomsForUserWithStreamOrdering]:
-        # We use `current_state_events` here and not `local_current_membership`
-        # as a) this gets called with remote users and b) this only gets called
-        # for rooms the server is participating in.
-        sql = """
-            SELECT room_id, e.instance_name, e.stream_ordering
-            FROM current_state_events AS c
-            INNER JOIN events AS e USING (room_id, event_id)
-            WHERE
-                c.type = 'm.room.member'
-                AND c.state_key = ?
-                AND c.membership = ?
-        """
-
-        txn.execute(sql, (user_id, Membership.JOIN))
-        return frozenset(
-            GetRoomsForUserWithStreamOrdering(
-                room_id, PersistedEventPosition(instance, stream_id)
-            )
-            for room_id, instance, stream_id in txn
-        )
-
     async def get_users_server_still_shares_room_with(
         self, user_ids: Collection[str]
     ) -> Set[str]:
@@ -701,13 +653,6 @@ class RoomMemberWorkerStore(EventsWorkerStore, CacheInvalidationWorkerStore):
         If a remote user only returns rooms this server is currently
         participating in.
         """
-        rooms = self.get_rooms_for_user_with_stream_ordering.cache.get_immediate(
-            (user_id,),
-            None,
-            update_metrics=False,
-        )
-        if rooms:
-            return frozenset(r.room_id for r in rooms)
 
         room_ids = await self.db_pool.simple_select_onecol(
             table="current_state_events",
diff --git a/synapse/storage/databases/main/stream.py b/synapse/storage/databases/main/stream.py
index be81025355..e74e0d2e91 100644
--- a/synapse/storage/databases/main/stream.py
+++ b/synapse/storage/databases/main/stream.py
@@ -371,7 +371,7 @@ def _make_generic_sql_bound(
 def _filter_results(
     lower_token: Optional[RoomStreamToken],
     upper_token: Optional[RoomStreamToken],
-    instance_name: str,
+    instance_name: Optional[str],
     topological_ordering: int,
     stream_ordering: int,
 ) -> bool:
@@ -384,8 +384,14 @@ def _filter_results(
     position maps, which we handle by fetching more than necessary from the DB
     and then filtering (rather than attempting to construct a complicated SQL
     query).
+
+    The `instance_name` arg is optional to handle historic rows, and is
+    interpreted as if it was "master".
     """
 
+    if instance_name is None:
+        instance_name = "master"
+
     event_historical_tuple = (
         topological_ordering,
         stream_ordering,
@@ -420,7 +426,7 @@ def _filter_results(
 def _filter_results_by_stream(
     lower_token: Optional[RoomStreamToken],
     upper_token: Optional[RoomStreamToken],
-    instance_name: str,
+    instance_name: Optional[str],
     stream_ordering: int,
 ) -> bool:
     """
@@ -436,7 +442,14 @@ def _filter_results_by_stream(
     position maps, which we handle by fetching more than necessary from the DB
     and then filtering (rather than attempting to construct a complicated SQL
     query).
+
+    The `instance_name` arg is optional to handle historic rows, and is
+    interpreted as if it was "master".
     """
+
+    if instance_name is None:
+        instance_name = "master"
+
     if lower_token:
         assert lower_token.topological is None
 
@@ -912,7 +925,6 @@ class StreamWorkerStore(EventsWorkerStore, SQLBaseStore):
                 prev_sender,
             ) in txn:
                 assert room_id is not None
-                assert instance_name is not None
                 assert stream_ordering is not None
 
                 if _filter_results_by_stream(
@@ -936,7 +948,8 @@ class StreamWorkerStore(EventsWorkerStore, SQLBaseStore):
                         # Event
                         event_id=event_id,
                         event_pos=PersistedEventPosition(
-                            instance_name=instance_name,
+                            # If instance_name is null we default to "master"
+                            instance_name=instance_name or "master",
                             stream=stream_ordering,
                         ),
                         # When `s.event_id = null`, we won't be able to get respective
@@ -952,13 +965,11 @@ class StreamWorkerStore(EventsWorkerStore, SQLBaseStore):
                         prev_event_id=prev_event_id,
                         prev_event_pos=(
                             PersistedEventPosition(
-                                instance_name=prev_instance_name,
+                                # If instance_name is null we default to "master"
+                                instance_name=prev_instance_name or "master",
                                 stream=prev_stream_ordering,
                             )
-                            if (
-                                prev_instance_name is not None
-                                and prev_stream_ordering is not None
-                            )
+                            if (prev_stream_ordering is not None)
                             else None
                         ),
                         prev_membership=prev_membership,
@@ -1270,7 +1281,9 @@ class StreamWorkerStore(EventsWorkerStore, SQLBaseStore):
                     stream_ordering=stream_ordering,
                 ):
                     return event_id, PersistedEventPosition(
-                        instance_name, stream_ordering
+                        # If instance_name is null we default to "master"
+                        instance_name or "master",
+                        stream_ordering,
                     )
 
             return None