Faster joins: omit partial rooms from eager syncs until the resync completes (#14870)

* Allow `AbstractSet` in `StrCollection`

Or else frozensets are excluded. This will be useful in an upcoming
commit where I plan to change a function that accepts `List[str]` to
accept `StrCollection` instead.

* `rooms_to_exclude` -> `rooms_to_exclude_globally`

I am about to make use of this exclusion mechanism to exclude rooms for
a specific user and a specific sync. This rename helps to clarify the
distinction between the global config and the rooms to exclude for a
specific sync.

* Better function names for internal sync methods

* Track a list of excluded rooms on SyncResultBuilder

I plan to feed a list of partially stated rooms for this sync to ignore

* Exclude partial state rooms during eager sync

using the mechanism established in the previous commit

* Track un-partial-state stream in sync tokens

So that we can work out which rooms have become fully-stated during a
given sync period.

* Fix mutation of `@cached` return value

This was fouling up a complement test added alongside this PR.
Excluding a room would mean the set of forgotten rooms in the cache
would be extended. This means that room could be erroneously considered
forgotten in the future.

Introduced in #12310, Synapse 1.57.0. I don't think this had any
user-visible side effects (until now).

* SyncResultBuilder: track rooms to force as newly joined

Similar plan as before. We've omitted rooms from certain sync responses;
now we establish the mechanism to reintroduce them into future syncs.

* Read new field, to present rooms as newly joined

* Force un-partial-stated rooms to be newly-joined

for eager incremental syncs only, provided they're still fully stated

* Notify user stream listeners to wake up long polling syncs

* Changelog

* Typo fix

Co-authored-by: Sean Quah <8349537+squahtx@users.noreply.github.com>

* Unnecessary list cast

Co-authored-by: Sean Quah <8349537+squahtx@users.noreply.github.com>

* Rephrase comment

Co-authored-by: Sean Quah <8349537+squahtx@users.noreply.github.com>

* Another comment

Co-authored-by: Sean Quah <8349537+squahtx@users.noreply.github.com>

* Fixup merge(?)

* Poke notifier when receiving un-partial-stated msg over replication

* Fixup merge whoops

Thanks MV :)

Co-authored-by: Mathieu Velen <mathieuv@matrix.org>

Co-authored-by: Mathieu Velten <mathieuv@matrix.org>
Co-authored-by: Sean Quah <8349537+squahtx@users.noreply.github.com>

1 files changed, 5 insertions, 10 deletions

diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py
index 3217127865..233f8c113d 100644
--- a/synapse/handlers/federation.py
+++ b/synapse/handlers/federation.py
@@ -1868,22 +1868,17 @@ class FederationHandler:
 
                 async with self._is_partial_state_room_linearizer.queue(room_id):
                     logger.info("Clearing partial-state flag for %s", room_id)
-                    success = await self.store.clear_partial_state_room(room_id)
+                    new_stream_id = await self.store.clear_partial_state_room(room_id)
 
-                    # Poke the notifier so that other workers see the write to
-                    # the un-partial-stated rooms stream.
-                    self._notifier.notify_replication()
-
-                if success:
+                if new_stream_id is not None:
                     logger.info("State resync complete for %s", room_id)
                     self._storage_controllers.state.notify_room_un_partial_stated(
                         room_id
                     )
 
-                    # Poke the notifier so that other workers see the write to
-                    # the un-partial-stated rooms stream.
-                    self._notifier.notify_replication()
-
+                    await self._notifier.on_un_partial_stated_room(
+                        room_id, new_stream_id
+                    )
                     return
 
                 # we raced against more events arriving with partial state. Go round