Add background task to clear out old event_auth

synapse/storage/event_federation.py

@@ -37,9 +37,16 @@ class EventFederationStore(SQLBaseStore):
     and backfilling from another server respectively.
     """
 
+    EVENT_AUTH_STATE_ONLY = "event_auth_state_only"
+
     def __init__(self, hs):
         super(EventFederationStore, self).__init__(hs)
 
+        self.register_background_update_handler(
+            self.EVENT_AUTH_STATE_ONLY,
+            self._background_delete_non_state_event_auth,
+        )
+
         hs.get_clock().looping_call(
             self._delete_old_forward_extrem_cache, 60 * 60 * 1000
         )
@@ -527,3 +534,52 @@ class EventFederationStore(SQLBaseStore):
 
         txn.execute(query, (room_id,))
         txn.call_after(self.get_latest_event_ids_in_room.invalidate, (room_id,))
+
+    @defer.inlineCallbacks
+    def _background_delete_non_state_event_auth(self, progress, batch_size):
+        def delete_event_auth(txn):
+            target_min_stream_id = progress.get("target_min_stream_id_inclusive")
+            max_stream_id = progress.get("max_stream_id_exclusive")
+
+            if not target_min_stream_id or not max_stream_id:
+                txn.execute("SELECT COALESCE(MIN(stream_ordering), 0) FROM events")
+                rows = txn.fetchall()
+                target_min_stream_id = rows[0][0]
+
+                txn.execute("SELECT COALESCE(MAX(stream_ordering), 0) FROM events")
+                rows = txn.fetchall()
+                max_stream_id = rows[0][0]
+
+            min_stream_id = max_stream_id - batch_size
+
+            sql = """
+                DELETE FROM event_auth
+                WHERE event_id IN (
+                    SELECT event_id FROM events
+                    LEFT JOIN state_events USING (room_id, event_id)
+                    WHERE ? <= stream_ordering AND stream_ordering < ?
+                        AND state_key IS null
+                )
+            """
+
+            txn.execute(sql, (min_stream_id, max_stream_id,))
+
+            new_progress = {
+                "target_min_stream_id_inclusive": target_min_stream_id,
+                "max_stream_id_exclusive": min_stream_id,
+            }
+
+            self._background_update_progress_txn(
+                txn, self.EVENT_AUTH_STATE_ONLY, new_progress
+            )
+
+            return min_stream_id >= target_min_stream_id
+
+        result = yield self.runInteraction(
+            self.EVENT_AUTH_STATE_ONLY, delete_event_auth
+        )
+
+        if not result:
+            yield self._end_background_update(self.EVENT_AUTH_STATE_ONLY)
+
+        defer.returnValue(batch_size)