We use the kubernetes plugin with kubernetes 1.15.3 on premise. Regarding sh steps per pod, we have only around 10, but invoke our build system via shell scripts which then work through Makefiles and invoke bash for every step of the Makefiles. It sums up to around 27k defunct bash processes that are not getting reaped and eventually we run into the error which i mentioned above.

So reading between the lines, repeatedly running a build which has one sh step that runs a script that launches a thousand subprocesses should eventually result in an error. That is something that can be tested and, if true, worked around.

I have been unable to reproduce the `Resource temporarily unavailable.` error when attempting to run pipelines that simulate the situation described.

I created a cluster in GKE using the gcloud cli. gcloud container clusters create <cluster-name> --machine-type=n1-standard-2 --cluster-version=latest. Installed Cloudbees Core for Modern Platforms version 2.204.3.7 (latest public release at the time I started testing) using Helm. Used kubectl get nodes to find the names of the nodes and gcloud beta compute ssh to connect to the nodes via ssh. Then running watch 'ps fauxwww | fgrep Z' to watch for zombie processes on each node.

Using groovy while (true) { sh 'sleep 1' } I was able to produce zombie processes on the node the build agent was assigned to. The process ran for 5 hours 17 minutes before using all the process resources. After the processes were exhausted the job exited with an error message that there were not processes available. After the pod running the job exited the zombie processes on the node were removed and the node continued to function.

Using `while :; do /usr/bin/sleep .01; done` as a way to generate subprocesses I've tested as the direct parameter of an `sh` step in a pipeline using both `jenkins/jnlp-slave` and `cloudbees/cloudbees-core-agent` images. Neither produced any zombie processes on the worker nodes of the Kubernetes cluster. To induce another layer of subprocess I also put that `while` line into a file and had the `sh` process execute that file, but it also did not produce any zombie processes on the worker nodes. Additionally I made that while loop a step in a Makefile and executed it that way, which also did not produce any zombies on the nodes.

I have been observing some issues on nodes.  I have been using amazon EKS for cluster and once in a while node ends up either with soft lockup or flips to NodeNotReady. I have tried to troubleshoot a lot but still now nothing concrete is figured out. I was working with AWS support and they told me that there were couple of other cases where they told similar behavior using Jenkins pods. One of the other patterns which I observed is, all the nodes which had issues had very high number of zombie processes, at least 4000+. I still haven't got any conclusive evidence to tell that issue is due to zombie process/Jenkins but the patterns all indicate that there could be something with k8s plugin of Jenkins which may be causing the issue.

Did any of you face the same issue?

i use   helm   deploy  bitnami/jenkins   had meet this