Allow multiple workers to write to receipts stream. (#16432)

Fixes #16417

1 files changed, 6 insertions, 1 deletions

diff --git a/synapse/handlers/sync.py b/synapse/handlers/sync.py

index f131c0e8e0..f75c1548ca 100644
--- a/synapse/handlers/sync.py
+++ b/synapse/handlers/sync.py
@@ -57,6 +57,7 @@ from synapse.types import (
     DeviceListUpdates,
     JsonDict,
     JsonMapping,
+    MultiWriterStreamToken,
     MutableStateMap,
     Requester,
     RoomStreamToken,
@@ -477,7 +478,11 @@ class SyncHandler:
                 event_copy = {k: v for (k, v) in event.items() if k != "room_id"}
                 ephemeral_by_room.setdefault(room_id, []).append(event_copy)
 
-            receipt_key = since_token.receipt_key if since_token else 0
+            receipt_key = (
+                since_token.receipt_key
+                if since_token
+                else MultiWriterStreamToken(stream=0)
+            )
 
             receipt_source = self.event_sources.sources.receipt
             receipts, receipt_key = await receipt_source.get_new_events(