I’ve inherited a rather large and busy jenkins controller. It’s on [Jenkins 2.346.2] and I’ve just upgraded it and agents to Java 17 from Java 8 in preparation for upgrading to the latest LTS
Performance has taken a huge hit, people are complaining, I’ve started the discussion around splitting this server into smaller servers but I’d still like to understand the reason for this slow down. I appreciate any help offered.
I’ve gone through logs and nothing is jumping out at me as a red flag, but I admit Java stacks are not my strong suit.
Did you retain the same Java memory arguments for Java 17 as you were using for Java 8? Was the Java 8 configuration specifying a garbage collection algorithm and garbage collection configuration? If so, then the Java 17 garbage collector configuration is quite different.
There is a CloudBees article on JVM configuration that might help. Darin Pope created a video on garbage collection configuration for the CloudBees products that you might use as a guide in your use of Jenkins. CloudBees CI is much more than Jenkins, but it has Jenkins at its base.
There is also a recording of a CloudBees webinar that includes JVM settings and performance.