max-pool-size for DB connections Keycloak version 11

Trying to investigate an issue regarding a keycloak deployment. From the documentation we're seeing that we should alter this property in the stanealone.xml to allow more

However , after altering the standalone xml to this

                </datasource>
                <datasource jndi-name="java:jboss/datasources/KeycloakDS" pool-name="KeycloakDS" enabled="true" use-java-context="true" use-ccm="true">
                    <connection-url>jdbc:postgresql://${env.DB_ADDR:postgres}/${env.DB_DATABASE:keycloak}${env.JDBC_PARAMS:}</connection-url>
                    <driver>postgresql</driver>
                    <pool>
                        <max-pool-size>200</max-pool-size>
                    </pool>

When we allow the JMX connection to the management console I notice this max pool size showing 19

Is there anything which could be overriding the max-pool-size setting we're using or how would one go about debugging where is derives the max-pool-size if not from the standalone.xml

Solution

I don't know why exactly you get this issue but I'll try to help to the best of my abilities.

Keycloak 11 uses Widlfy 20, which offers several options to configure the datasource.

Please try to set

pool-use-strict-min to true
pool-prefill to true
min-pool-size to 200
initial-pool-size to 200

Also, monitor the number of opened connection on your Postgres database, and check if they recoup with the JMX report you got.

Finally, if none of these cause a change in your situation I can only suggest to try another ManagedConnectionPool implementation (see mcp attribute)