Merge pull request ceph#64112 from zdover23/wip-doc-2025-06-23-backport-64103-to-tentacle

tentacle: doc/radosgw: improve "pubsub_push_pending" info

Reviewed-by: Anthony D'Atri <[email protected]>
Reviewed-by: Yuval Lifshitz <[email protected]>

Author: zdover23

doc/radosgw/notifications.rst

@@ -129,7 +129,10 @@ Notification Performance Statistics
 - ``pubsub_event_triggered``: a running counter of events that have at least one topic associated with them
 - ``pubsub_push_ok``: a running counter, for all notifications, of events successfully pushed to their endpoints
 - ``pubsub_push_fail``: a running counter, for all notifications, of events that failed to be pushed to their endpoints
-- ``pubsub_push_pending``: the gauge value of events pushed to an endpoint but not acked or nacked yet
+- ``pubsub_push_pending``: the gauge value of events pushed to an endpoint but
+  not acked or nacked yet. This does not include the notifications waiting in
+  the persistent queue. Only the notifications that are in flight in both
+  persistent and non-persistent cases are counted.
 
 .. note::