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<@tmpl.guide
title="Concepts for database connection pools"
summary="Understand these concepts to avoid resource exhaustion and congestion"
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This section is intended when you want to understand considerations and best practices on how to configure database connection pools for {project_name}.
For a configuration where this is applied, visit <@links.ha id="deploy-keycloak-kubernetes" />.

== Concepts

Creating new database connections is expensive as it takes time.
Creating them when a request arrives will delay the response, so it is good to have them created before the request arrives.
It can also contribute to a https://en.wikipedia.org/wiki/Cache_stampede[stampede effect] where creating a lot of connections in a short time makes things worse as it slows down the system and blocks threads.
Closing a connection also invalidates all server side statements caching for that connection.

include::partials/database-connections/configure-db-connection-pool-best-practices.adoc[]

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