[Doc] Document Grafana 12.4 changes

documentation/docs/alert/alert_rules.md

@@ -137,3 +137,9 @@ If you want to learn about creating Grafana alerts instead, check out [Grafana's
     - **Label** must be an exact match. You can find a complete list of labels using the <i class="uil uil-compass"></i> **Explore** menu in PMM.
 
 5. Click **Save and Exit** to close the page and go to the **Alert Rules** tab where you can review, edit and silence your new alert.
+
+## Recording rules
+
+Record an alert rules to pre-compute a query on a schedule and store the result as a new metric, which you can then reference in alert rules. This is useful when the same query powers multiple alert rules, for example, average CPU load across all nodes or replication lag across a cluster.
+
+To create a recording rule, click **Alerting > Alert rules** + New recording rule**. For full instructions, see [Create recording rules](https://grafana.com/docs/grafana/latest/alerting/alerting-rules/create-recording-rules/) in the Grafana documentation.

documentation/docs/install-pmm/install-pmm-client/connect-database/azure.md

@@ -8,7 +8,7 @@
 The Microsoft Azure feature is turned off by default. To turn it on:
 {.power-number}
 
-1. Go to **Configuration > Settings > Advanced settings**.
+1. Go to **Configuration > Settings > Advanced Settings**.
 
 2. Click the <i class="uil uil-toggle-off"></i> toggle in the **Technical preview features** section of the page.
 

documentation/docs/reference/ui/ui_components.md

@@ -24,7 +24,7 @@ You'll find these options in the left-side menu:
 | :material-monitor-dashboard:| Operating System  | Monitor server-level metrics including CPU, memory, disk, and network performance. |
 | :material-view-grid-outline:| All Dashboards | Create and organize dashboards, create [folders](../../use/dashboards-panels/manage-dashboards/create-folders.md), import dashboards, create playlists, and manage snapshots. |
 | :material-chart-timeline-variant: | Query Analytics (QAN) | Analyze database queries over time, identify slow queries, optimize performance, and troubleshoot issues. |
-| :material-compass-outline:  | Explore | Run ad-hoc queries with [PromQL](https://prometheus.io/docs/prometheus/latest/querying/basics/) to investigate specific metrics without creating dashboards. |
+| :material-compass-outline:  | Explore | Investigate metrics without creating dashboards. **PromQL builder** lets you write custom [PromQL](https://prometheus.io/docs/prometheus/latest/querying/basics/) queries. You can also enable **Explore metrics** to visually browse metrics without writing queries. **Explore metrics** requires [enabling the Grafana Metrics Drilldown plugin](#enable-explore-metrics). |
 | :material-bell-outline: |  | Alerts | Create and manage [alerts](../../alert/index.md) that notify you when metrics exceed thresholds. |
 |:material-earth: | Advisors | Run health assessment checks on your databases and view recommendations for improving performance.|
 | :material-flask-outline: | Inventory | View and manage all monitored nodes, services, and agents registered in PMM. Check database and agent status, organize services by clusters, and add or remove monitored instances. |
@@ -68,3 +68,16 @@ Filter your monitoring data using these contextual options:
 - **PMM Annotations**: Toggle visibility of important events on your timelines
 
 These selectors change based on the dashboard you're viewing, showing only relevant options.
+
+## Enable Explore metrics
+
+Explore metrics lets you visually browse and filter available metrics without writing PromQL queries. It is powered by the Grafana Metrics Drilldown plugin, which you can enable from the **Plugins** page:
+{.power-number}
+
+1. Go to the **Home** page and type **plugins** in the search bar.
+2. On the **Plugins** page, search for **Grafana Metrics Drilldown**.
+3. Select the plugin and click **Install**.
+
+This adds the **Explore metrics** option under **Explore** in the left sidebar. For more information, see [Grafana Metrics Drilldown](https://grafana.com/docs/grafana-cloud/visualizations/simplified-exploration/metrics).
+
+![Explore metrics in the PMM sidebar](../../images/PMM_Explore_metrics.jpg)

documentation/docs/release-notes/3.8.0.md

@@ -19,13 +19,17 @@ TODO
 
 PMM 3.8.0 ships with [Grafana 12.4](https://grafana.com/docs/grafana/latest/whatsnew/whats-new-in-v12-0/), so you will notice several day-to-day monitoring improvements right away:
 
+**Less alert noise**: Alert rules now support a [**Recovering** state](https://grafana.com/docs/grafana/latest/whatsnew/whats-new-in-v12-0/#recovering-state-for-alert-rules). This helps avoid repeated fire/resolved notifications when a metric keeps moving above and below an alert threshold, so you get fewer noisy alerts for spiky metrics like replication lag, query response time, and connection counts.
+
+    ![Recovering alert state](../images/recovering-alert.jpg)
+
 **Faster monitoring dashboards**: Tables in PMM dashboards load, sort, and filter significantly faster. This affects dashboards across PMM including **Nodes Overview**, **MySQL User Details**, **PostgreSQL Instances Overview**, MongoDB, and HA/PXC **Cluster Summary**.
 
-**Less alert noise**: Alert rules now support a [**Recovering** state](https://grafana.com/docs/grafana/latest/whatsnew/whats-new-in-v12-0/#recovering-state-for-alert-rules). This helps avoid repeated fire/resolved notifications when a metric keeps moving above and below an alert threshold, so you get fewer noisy alerts for spiky metrics like replication lag, query response time, and connection counts.
+**Explore metrics now opt-in**: Starting with Grafana 12, **Explore metrics** is disabled by default. If you used it to visually browse metrics without writing queries, you need to re-enable it. Go to the Home page, type **plugins** in the search bar and install **Grafana Metrics Drilldown**. Once enabled, **Explore metrics** will reappear under **Explore** in the left sidebar. 
 
-**Custom dashboard compatibility**: All PMM-provided dashboards are unaffected by Grafana 12's Angular removal. If you have custom dashboards using legacy **Graph (old)** or **Table (old)** panels, Grafana will auto-migrate them on first load.
+**Recording rules**: Alert rules now support [**recording rules**](https://grafana.com/docs/grafana/latest/alerting/alerting-rules/create-recording-rules/). A recording rule runs a query on a schedule and saves the result as a new metric, so your alerts reference the pre-computed result instead of re-running the full query on every evaluation cycle. This is especially useful when the same query powers multiple alert rules, for example, average CPU load across all nodes or replication lag across a cluster.
 
-**Recording rules**: Alert rules now support [**recording rules**](https://grafana.com/docs/grafana/latest/alerting/alerting-rules/create-recording-rules/), which pre-calculate frequently used or expensive queries and store the results as new metrics. This can simplify complex alert conditions and improve query performance at scale.
+**More changes in Grafana 12**: Grafana 12 removes Angular support. If you have custom dashboards using legacy **Graph (old)** or **Table (old)** panels, they are automatically converted to **Time series** and **Table** panels the first time you open them after upgrading to PMM 3.8.0. For the full list of changes, see the [Grafana 12 release notes](https://grafana.com/docs/grafana/latest/whatsnew/whats-new-in-v12-0/).
 
 ## 📦 Components upgrade
 
@@ -41,6 +45,7 @@ PMM 3.8.0 ships with [Grafana 12.4](https://grafana.com/docs/grafana/latest/what
 
 ## 📈 Improvements
 
+
 - [PMM-12392](https://perconadev.atlassian.net/browse/PMM-12392): Improved how PMM collects processlist data on MySQL 5.7.39+ and 8.0.22+ by switching from Information Schema to Performance Schema. On busy MySQL instances, this reduces the chance of query blocking and deadlocks, lowering the overall monitoring impact on your MySQL server workload.
 
 - [PMM-14937](https://perconadev.atlassian.net/browse/PMM-14937): When adding a MySQL, PostgreSQL, MongoDB, ProxySQL, Valkey, Amazon RDS, or Azure service, you can now set a **Connection timeout** to control how long PMM waits before giving up on a connection attempt. This is useful when monitoring remote or high-latency databases where the default timeout is too short.
@@ -62,6 +67,7 @@ PMM 3.8.0 ships with [Grafana 12.4](https://grafana.com/docs/grafana/latest/what
 - [PMM-14512](https://perconadev.atlassian.net/browse/PMM-14512): Fixed the **BP Data Dirty** panel on the **MySQL InnoDB Details** dashboard showing no data after upgrading from PMM 2. The panel now correctly displays the ratio of dirty to data pages in the InnoDB buffer pool.
 
 - [PMM-14851](https://perconadev.atlassian.net/browse/PMM-14851): Fixed a bug in the PMM Helm chart that could cause `ClusterRole` to fail when deploying PMM on Kubernetes. The chart now deploys without RBAC errors.
+
 - [PMM-14934](https://perconadev.atlassian.net/browse/PMM-14934): Fixed an issue where the `GF_SECURITY_ADMIN_USER` and `GF_SECURITY_ADMIN_PASSWORD` environment variables were ignored when starting PMM Server with a named Docker volume (`-v pmm-data:/srv`). You can now use these variables to set the admin username and password at first start, regardless of how the data volume is mounted. As part of this fix, **the first start after upgrading takes about 20–30 seconds longer** than usual while PMM initializes. Subsequent starts are unaffected. PMM HA deployments are unimpacted.
 
 ## 🚀 Ready to upgrade to PMM 3.8.0?