From a711ae78a8f8ba406ff122035c8bf096fac9a26c Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Wed, 23 Feb 2022 14:22:22 +0000
Subject: Add logging to `/sync` for debugging #11916 (#12068)

---
 synapse/handlers/sync.py | 9 +++++++++
 1 file changed, 9 insertions(+)

(limited to 'synapse/handlers')

diff --git a/synapse/handlers/sync.py b/synapse/handlers/sync.py
index 98eaad3318..0aa3052fd6 100644
--- a/synapse/handlers/sync.py
+++ b/synapse/handlers/sync.py
@@ -697,6 +697,15 @@ class SyncHandler:
         else:
             # no events in this room - so presumably no state
             state = {}
+
+            # (erikj) This should be rarely hit, but we've had some reports that
+            # we get more state down gappy syncs than we should, so let's add
+            # some logging.
+            logger.info(
+                "Failed to find any events in room %s at %s",
+                room_id,
+                stream_position.room_key,
+            )
         return state
 
     async def compute_summary(
-- 
cgit 1.4.1