GKE automatically restarted cluster

Question

Auto-Scaling is OFF and Cluster-Upgrade is OFF but still dont know why cluster get restarted today morning. All Nodes got replace/change and All Pods got restarted

Reason is that it got restarted due to node got upgrade from 1.22 to 1.23 version

I have Regular Version in GKE Cluster

Answer 1

You should double-check with Google support (if you have a support plan), but I know from painful experience that if you're running a version of GKE that falls out of support, they may force-upgrade you to keep you within support, even if you have cluster upgrade turned off -- unless you use a maintenance exclusion.

The REGULAR channel release notes are here: https://cloud.google.com/kube.netes-engine/docs/release-notes-regular

The December 5th one is probably the one that affected you.

Answer 2

If you disable node auto-upgrade, you are responsible for ensuring that the cluster's nodes run a version compatible with the cluster's version, and that the version adheres to the Kube.netes version and version skew support policy .

Nodes running versions that have reached theirend of life date are auto-upgraded even when auto-upgrade is disabled, to ensure supportability and version skew compatibility.

For more information you can read this link .

You can also check this link for temporary mitigation.