1 files changed, 10 insertions, 0 deletions
diff --git a/docs/sample_config.yaml b/docs/sample_config.yaml
index 186cdbedd2..93c0edd8ce 100644
--- a/docs/sample_config.yaml
+++ b/docs/sample_config.yaml
@@ -958,6 +958,16 @@ account_threepid_delegates:
 #sentry:
 #    dsn: "..."
 
+# Flags to enable Prometheus metrics which are not suitable to be
+# enabled by default, either for performance reasons or limited use.
+#
+metrics_flags:
+    # Publish synapse_federation_known_servers, a g auge of the number of
+    # servers this homeserver knows about, including itself. May cause
+    # performance problems on large homeservers.
+    #
+    #known_servers: true
+
 # Whether or not to report anonymized homeserver usage statistics.
 # report_stats: true|false