From b4b2fd2ecee26214fa6b322bcb62bec1ea324c1a Mon Sep 17 00:00:00 2001
From: Richard van der Hoff <1389908+richvdh@users.noreply.github.com>
Date: Tue, 1 Jun 2021 12:04:47 +0100
Subject: add a cache to have_seen_event (#9953)

Empirically, this helped my server considerably when handling gaps in Matrix HQ. The problem was that we would repeatedly call have_seen_events for the same set of (50K or so) auth_events, each of which would take many minutes to complete, even though it's only an index scan.
---
 synapse/storage/databases/main/cache.py | 1 +
 1 file changed, 1 insertion(+)

(limited to 'synapse/storage/databases/main/cache.py')

diff --git a/synapse/storage/databases/main/cache.py b/synapse/storage/databases/main/cache.py
index f7872501a0..c57ae5ef15 100644
--- a/synapse/storage/databases/main/cache.py
+++ b/synapse/storage/databases/main/cache.py
@@ -168,6 +168,7 @@ class CacheInvalidationWorkerStore(SQLBaseStore):
         backfilled,
     ):
         self._invalidate_get_event_cache(event_id)
+        self.have_seen_event.invalidate((room_id, event_id))
 
         self.get_latest_event_ids_in_room.invalidate((room_id,))
 
-- 
cgit 1.5.1