▲Fixing a kubelet memory leak in Kubernetes 1.36(heyoncall.com)
35 points by compumike 16 hours ago | 5 comments
▲compumike 15 hours ago
Author here! If you're running a Kubernetes cluster, I recommend you check `kubectl version` and see if you're running "Server Version: v1.36.[0,1,2]". If so, you may want to use the one-liner at the end of the article to check your "process_resident_memory_bytes" on each node, and consider restarting kubelet as a temporary workaround to tame the memory leak until v1.36.3 is released.
▲__turbobrew__ 24 minutes ago
A good reason to health check the kubelet process and restart it when the checks fail.
▲compumike 9 minutes ago
What kind of health checks? In my case, the kubelet process was staying alive and responsive to queries, I believe due to:

  # cat /proc/$(pgrep kubelet)/oom_score_adj
  -999
  
  (from OOMScoreAdjust=-999 in /etc/systemd/system/kubelet.service)
With this score, the Linux OOM killer wouldn't touch it, but any of my Pods were fair game.
▲rirze 1 hour ago
Very cool. It's often daunting to contribute to such a well-established and recognizable project, but this is exactly how it should work.
▲CamouflagedKiwi 1 hour ago
Nice find.

Can't help but feel this is one of the subtle traps hidden beneath the advice that contexts aren't supposed to be stored. I know it's not always that easy, of course.

▲compumike 34 minutes ago
Thanks. I know there's a `go vet` tool that's run as part of Kubernetes CI, and one of its checks is:

  lostcancel: check cancel func returned by context.WithCancel is called
I'm not 100% sure why `go vet` didn't catch this issue, but storing the cancelFn in the struct is probably part of the reason. Any Go experts know if that's the case?
▲fsuts 39 minutes ago
Not all heroes wear capes! Well done