
:guide-id: metrics-for-troubleshooting-database
:guide-title: Database Metrics
:guide-summary: Use metrics to describe {project_name}'s connection to the database.
:guide-priority: 999
:guide-tile-visible: false
:version: 26.2.4

include::../attributes.adoc[]

[[metrics-for-troubleshooting-database]]
= Database Metrics

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WARNING: This {section} is describing a feature which is currently in preview.
ifeval::["" == ""]
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endif::[]
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This is part of the link:{links_observability_metrics-for-troubleshooting_url}[{links_observability_metrics-for-troubleshooting_name}] {section}.

== Prerequisites

* Metrics need to be enabled for {project_name}. Follow the link:{links_observability_configuration-metrics_url}[{links_observability_configuration-metrics_name}] {section} for more details.
* A monitoring system collecting the metrics.

== Database connection pool metrics

Configure {project_name} to use a fixed size database connection pool.
See the link:{links_high-availability_concepts-database-connections_url}[{links_high-availability_concepts-database-connections_name}] {section} for more information.

[TIP]
====
If there is a high count of threads waiting for a database connection, increasing the database connection pool size is not always the best option. It might overload the database which would then become the bottleneck. Consider the following options instead:

* Reduce the number of HTTP worker threads using the option `http-pool-max-threads` to make it match the available database connections, and thereby reduce contention and resource usage in {project_name} and increase throughput.
* Check which database statements are executed on the database. If you see, for example, a lot of information about clients and groups being fetched, and the `users` and `realms` cache are full, this might indicate that it is time to increase the sizes of those caches and see if this reduces your database load.
====

|===
|Metric |Description

m| agroal_available_count
| Idle database connections.

m| agroal_active_count
| Database connections used in ongoing transactions.

m| agroal_awaiting_count
| Threads waiting for a database connection to become available.

|===

== Next steps

Return back to the link:{links_observability_metrics-for-troubleshooting_url}[{links_observability_metrics-for-troubleshooting_name}] or proceed to link:{links_observability_metrics-for-troubleshooting-http_url}[{links_observability_metrics-for-troubleshooting-http_name}].


