Merge pull request #13756 from rabbitmq/4.1-release-notes-prometheus

[skip-ci] Additional Prometheus-related release notes

Author: michaelklishin

release-notes/4.1.0.md

@@ -97,9 +97,9 @@ This release series supports upgrades from `4.0.x` and `3.13.x`.
 [Blue/Green Deployment](https://www.rabbitmq.com/docs/blue-green-upgrade)-style upgrades are avaialble for migrations
 from RabbitMQ `3.12.x` series.
 
-### Required Feature Flags
+### New Required Feature Flags
 
-None/TBD.
+None. The required feature flag set is the same as in `4.0.x`.
 
 ### Mixed version cluster compatibility
 
@@ -407,6 +407,23 @@ This section can be incomplete and will be expanded as 4.1 approaches its releas
 
    GitHub issue: [#12765](https://github.com/rabbitmq/rabbitmq-server/pull/12765)
 
+ * New metric: `queue_identity_info`.
+
+   `queue_identity_info` is a new metric whose labels describe the type
+   of the queue and its membership status (leader/follower) on the scraped node.
+
+   GitHub issue: [#13583](https://github.com/rabbitmq/rabbitmq-server/pull/13583)
+
+ * `rabbitmq_identity_info` now includes a new label, `rabbitmq_endpoint`.
+
+   The label allows operators differntiate between metrics scraped from different
+   RabbitMQ endpoints (the per-object one and the aggregated one).
+
+   Since some metric names are identical regardless of whether they were
+   scraped from `/metrics` and `/metrics/per-object`, scraping both endpoints could lead to
+   duplicates and confusion.
+
+   GitHub issue: [#13218](https://github.com/rabbitmq/rabbitmq-server/pull/13218)
 
 ### Grafana Dashboards