Kubernetes node is unreachable and some workloads may be rescheduled.
The performance of the cluster deployments is affected, depending on the overall workload and the type of the node.
The notification details should list the node that’s not reachable. For Example:
- alertname = KubeNodeUnreachable ... - node = node1.example.com ...
Login to the cluster. Check the status of that node:
$ kubectl get node $NODE -o yaml
The output should describe why the node is not reachable.
Common failure scenarios:
- disruptive software upgrades
- network patitioning due to hardware failures
- firewall rules
- virtual machines suspended due to storage area network problems
- system crashes / freezes due to software or hardware malfunctions
In case of maintenance ensure to cordon and drain node.
In other cases ensure storage and networking redundancy if applicable.