Since the update from 2.346.2 to 2.346.3, multiple builds running in parallel (either concurrent builds from the same pipeline or multiple builds from different pipelines) cause memory spikes that exceed the heap size of the JVM by a lot which leads to kubernetes killing the jenkins pod (OOMkilled).

Setup:

Kubernetes container with memory request+limit = 8gb

Jenkins -Xmx=4g

Steps to reproduce:

• Upgrade to 2.346.3
• Run multiple builds in parallel (they should take some minutes)
• In the jenkins pod, you can see that the memory of the jenkins process spikes within a couple of seconds
• As soon as the memory exceeds the memory limit of the container, kubernetes kills the pod. We tested the same scenario with a memory limit of 32gb and -Xmx=4g which leads to the issue taking longer to occur.

Downgrading to 2.346.2 solved the issue.

Could it be a plugin?

The exact same set of plugins works with 2.346.2.