Fix bug where we failed to delete old push actions (#13194)

This happened if we encountered a stream ordering in `event_push_actions` that had more rows than the batch size of the delete, as If we don't delete any rows in an iteration then the next time round we get the exact same stream ordering and get stuck.

1 files changed, 4 insertions, 2 deletions

diff --git a/synapse/storage/databases/main/event_push_actions.py b/synapse/storage/databases/main/event_push_actions.py
index 32536430aa..a3edcbb398 100644
--- a/synapse/storage/databases/main/event_push_actions.py
+++ b/synapse/storage/databases/main/event_push_actions.py
@@ -1114,7 +1114,7 @@ class EventPushActionsWorkerStore(ReceiptsWorkerStore, StreamWorkerStore, SQLBas
             txn.execute(
                 """
                 SELECT stream_ordering FROM event_push_actions
-                WHERE stream_ordering < ? AND highlight = 0
+                WHERE stream_ordering <= ? AND highlight = 0
                 ORDER BY stream_ordering ASC LIMIT 1 OFFSET ?
             """,
                 (
@@ -1129,10 +1129,12 @@ class EventPushActionsWorkerStore(ReceiptsWorkerStore, StreamWorkerStore, SQLBas
             else:
                 stream_ordering = max_stream_ordering_to_delete
 
+            # We need to use a inclusive bound here to handle the case where a
+            # single stream ordering has more than `batch_size` rows.
             txn.execute(
                 """
                 DELETE FROM event_push_actions
-                WHERE stream_ordering < ? AND highlight = 0
+                WHERE stream_ordering <= ? AND highlight = 0
                 """,
                 (stream_ordering,),
             )