Merge pull request #64140 from zdover23/wip-doc-2025-06-25-backport-64106-to-reef

reef: doc/radosgw: add "persistent_topic_size"

Reviewed-by: Anthony D'Atri <anthony.datri@gmail.com>

diff --cc doc/radosgw/notifications.rst
index e3d3b3bd05549e912154b84600d86defb99c129b,6b89907d0a1d2d56207a464f77f9cec969c9d7c7..3cfac9a00887f961041c659953009edecafa18a5
--- 1/doc/radosgw/notifications.rst
--- 2/doc/radosgw/notifications.rst
+++ b/doc/radosgw/notifications.rst
@@@ -103,7 -103,9 +103,8 @@@ Remove a topic by running the followin
  Notification Performance Statistics
  -----------------------------------
  
+ - ``persistent_topic_size``: queue size in bytes. 
  - ``pubsub_event_triggered``: a running counter of events that have at least one topic associated with them
 -- ``pubsub_event_lost``: a running counter of events that had topics associated with them, but that were not pushed to any of the endpoints
  - ``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