Rudder

A first analysis on normal load shows that the pool is correctly used. We enabled logs by adding system variables to JVM:

JAVA_OPTIONS="-Dcom.unboundid.ldap.sdk.debug.enabled=true
-Dcom.unboundid.ldap.sdk.debug.level=INFO
-Dcom.unboundid.ldap.sdk.debug.type=connection-pool" 

Other log level are "WARNING" and "SEVERE".

SEVERE is for error like not being able to create a connection when needed, WARNING is mostly for why connection get closed or defunct, and INFO will show each and every connectioin check out and release.

With INFO level, we get lines like that:

INFO: { "timestamp":"2021-05-19T20:46:32.734Z", "debug-type":"connection-pool", "level":"INFO", "thread-id":46, "thread-name":"zio-default-blocking-3-396918327", "connection-pool-name":null, "connection-id":1, "connected-to-address":"localhost", "connected-to-port":389, "current-available-connections":1, "maximum-available-connections":2, "message":"Checked out an immediately available pooled connection", "ldap-sdk-version":"5.0.1", "ldap-sdk-revision":"3290ee33d4aa17df1aadb4d814d6534375f395a9" }
May 19, 2021 8:46:52 PM com.unboundid.util.Debug log
INFO: { "timestamp":"2021-05-19T20:46:52.211Z", "debug-type":"connection-pool", "level":"INFO", "thread-id":56, "thread-name":"zio-default-blocking-5-396918327", "connection-pool-name":null, "connection-id":2, "connected-to-address":"localhost", "connected-to-port":389, "current-available-connections":2, "maximum-available-connections":2, "message":"Released a connection back to the pool", "ldap-sdk-version":"5.0.1", "ldap-sdk-revision":"3290ee33d4aa17df1aadb4d814d6534375f395a9" }
May 19, 2021 8:47:07 PM com.unboundid.util.Debug log
INFO: { "timestamp":"2021-05-19T20:47:07.281Z", "debug-type":"connection-pool", "level":"INFO", "thread-id":56, "thread-name":"zio-default-blocking-5-396918327", "connection-pool-name":null, "connection-id":0, "connected-to-address":"localhost", "connected-to-port":389, "current-available-connections":1, "maximum-available-connections":2, "message":"Checked out an immediately available pooled connection", "ldap-sdk-version":"5.0.1", "ldap-sdk-revision":"3290ee33d4aa17df1aadb4d814d6534375f395a9" }

So everything seems fine, appart the pool name (see: #19284).

Waiting for more analysis under load.