From a3f8ec284a766883f4fadabbe91bc89ca7ca2a50 Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Thu, 26 Sep 2024 22:55:45 +0100
Subject: [PATCH] Move metrics out of hot path

We can update the counter once outside of the loop.
---
 synapse/notifier.py | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/synapse/notifier.py b/synapse/notifier.py
index 7a2b54036c..e28c6eddb9 100644
--- a/synapse/notifier.py
+++ b/synapse/notifier.py
@@ -63,6 +63,7 @@ from synapse.types import (
 )
 from synapse.util.async_helpers import ObservableDeferred, timeout_deferred
 from synapse.util.metrics import Measure
+from synapse.util.stringutils import shortstr
 from synapse.visibility import filter_events_for_client
 
 if TYPE_CHECKING:
@@ -152,17 +153,6 @@ class _NotifierUserStream:
         self.last_notified_ms = time_now_ms
         notify_deferred = self.notify_deferred
 
-        log_kv(
-            {
-                "notify": self.user_id,
-                "stream": stream_key,
-                "stream_id": stream_id,
-                "listeners": self.count_listeners(),
-            }
-        )
-
-        users_woken_by_stream_counter.labels(stream_key).inc()
-
         with PreserveLoggingContext():
             self.notify_deferred = ObservableDeferred(defer.Deferred())
             notify_deferred.callback(self.current_token)
@@ -350,6 +340,10 @@ class Notifier:
             except Exception:
                 logger.exception("Failed to notify listener")
 
+        users_woken_by_stream_counter.labels(StreamKeyType.UN_PARTIAL_STATED_ROOMS).inc(
+            len(user_streams)
+        )
+
         # Poke the replication so that other workers also see the write to
         # the un-partial-stated rooms stream.
         self.notify_replication()
@@ -519,12 +513,16 @@ class Notifier:
         rooms = rooms or []
 
         with Measure(self.clock, "on_new_event"):
-            user_streams = set()
+            user_streams: Set[_NotifierUserStream] = set()
 
             log_kv(
                 {
                     "waking_up_explicit_users": len(users),
                     "waking_up_explicit_rooms": len(rooms),
+                    "users": shortstr(users),
+                    "rooms": shortstr(rooms),
+                    "stream": stream_key,
+                    "stream_id": new_token,
                 }
             )
 
@@ -550,6 +548,8 @@ class Notifier:
                 except Exception:
                     logger.exception("Failed to notify listener")
 
+            users_woken_by_stream_counter.labels(stream_key).inc(len(user_streams))
+
             self.notify_replication()
 
             # Notify appservices.