Question

A team reports that a newly deployed pod named 'batch-worker' has been stuck in the Pending state for 10 minutes. Running 'kubectl describe pod batch-worker' shows the event message: '0/5 nodes are available: 5 node(s) didn't match Pod's node affinity/selector.' All 5 worker nodes are Ready and have ample CPU and memory. What is the most likely cause and the correct first step to resolve it?

Accepted Answer

The pod's nodeSelector or nodeAffinity requires a label that no node currently has; inspect the pod spec and node labels, then either label a node or correct the selector.

Answer

The scheduler is down; restart the kube-scheduler static pod on the control plane to allow scheduling to proceed.

Answer

All nodes are cordoned; run 'kubectl uncordon' on each node to make them schedulable again.

Answer

The pod requests more resources than any node can provide; reduce the pod's CPU and memory requests.