Kubernetes Cookbook - Second Edition

Pod recovery by StatefulSet

StatefulSet behaves differently to DaemonSet during Pod recreation. In StatefulSet managed Pods, the Pod name is always consisted to assign an ordered number such as hdfs-datanode-0, hdfs-datanode-1 andhdfs-datanode-2, and if you delete one of them, a new Pod will take over the same Pod name.

To simulate this, let's delete one DataNode (hdfs-datanode-1) to see how StatefulSet recreates a Pod:

$ kubectl get podsNAME              READY     STATUS    RESTARTS   AGEhdfs-datanode-0   1/1       Running   0          3mhdfs-datanode-1   1/1       Running   0          2mhdfs-datanode-2   1/1       Running   0          2mhdfs-namenode-0   1/1       Running   0          23m //delete DataNode-1$ kubectl delete pod hdfs-datanode-1pod "hdfs-datanode-1" deleted //DataNode-1 is Terminating$ kubectl get podsNAME READY STATUS ...