Use _ instead of . as a metric namespacing separator, for Prometheus

1 files changed, 1 insertions, 1 deletions

diff --git a/synapse/handlers/presence.py b/synapse/handlers/presence.py

index 698946a48b..c6d6aef53b 100644
--- a/synapse/handlers/presence.py
+++ b/synapse/handlers/presence.py
@@ -136,7 +136,7 @@ class PresenceHandler(BaseHandler):
         self._user_cachemap = {}
         self._user_cachemap_latest_serial = 0
 
-        metrics.register_callback("user_cachemap:size",
+        metrics.register_callback("userCachemap:size",
             lambda: len(self._user_cachemap)
         )