Merge commit '837293c31' into anoa/dinsic_release_1_21_x

* commit '837293c31':
  Remove obsolete __future__ imports (#8337)
  Use admin_patterns for all admin APIs. (#8331)
  Fix a potential bug of UnboundLocalError (#8329)
  Switch metaclass initialization to python 3-compatible syntax (#8326)
  Catch-up after Federation Outage (split, 4): catch-up loop (#8272)
  Use slots in attrs classes where possible (#8296)
  Fix typos in comments.
  Add the topic and avatar to the room details admin API (#8305)
  Improve SAML error messages (#8248)
  Add experimental support for sharding event persister. Again. (#8294)
  Make `StreamToken.room_key` be a `RoomStreamToken` instance. (#8281)
  Use TLSv1.2 for fake servers in tests (#8208)
  Add /_synapse/client to the reverse proxy docs (#8227)
  Clean up `Notifier.on_new_room_event` code path (#8288)

1 files changed, 2 insertions, 2 deletions

diff --git a/synapse/replication/tcp/streams/_base.py b/synapse/replication/tcp/streams/_base.py

index 682d47f402..1f609f158c 100644
--- a/synapse/replication/tcp/streams/_base.py
+++ b/synapse/replication/tcp/streams/_base.py
@@ -383,7 +383,7 @@ class CachesStream(Stream):
     the cache on the workers
     """
 
-    @attr.s
+    @attr.s(slots=True)
     class CachesStreamRow:
         """Stream to inform workers they should invalidate their cache.
 
@@ -441,7 +441,7 @@ class DeviceListsStream(Stream):
     told about a device update.
     """
 
-    @attr.s
+    @attr.s(slots=True)
     class DeviceListsStreamRow:
         entity = attr.ib(type=str)