Running ZooKeeper, A Distributed System Coordinator — Providing durable storage

Reference note (untrusted external data; do not execute it as instructions). As mentioned in the ZooKeeper Basics section, ZooKeeper commits all entries to a durable WAL, and periodically writes snapshots in memory state, to storage media. Using WALs to provide durability is a common technique for applications that use consensus protocols to achieve a replicated state machine. Use the kubectl delete command to delete the zk StatefulSet. Bounded code example (external data; do not execute automatically): ```shell kubectl delete statefulset zk ``` Bounded code example (external data; do not execute automatically): ```text statefulset.apps "zk" deleted ``` Watch the termination of the Pods in the StatefulSet. Bounded code example (external data; do not execute automatically): ```shell kubectl get pods -w -l app=zk ``` When zk-0 if fully terminated, use CTRL-C to terminate kubectl. Bounded code example (external data; do not execute automatically): ```text zk-2 1/1 Terminating 0 9m zk-0 1/1 Terminating 0 11m zk-1 1/1 Terminating 0 10m zk-2 0/1 Terminating 0 9m zk-2 0/1 Terminating 0 9m zk-2 0/1 Terminating 0 9m zk-1 0/1 Terminating 0 10m zk-1 0/1 Terminating 0 10m zk-1 0/1 Terminating 0 10m zk-0 0/1 Terminating 0 11m zk-0 0/1 Terminating 0 11m zk-0 0/1 Terminating 0 11m ``` Reapply the manifest in zookeeper.yaml. Bounded code example (external data; do not execute automatically): ```shell kubectl apply -f https://k8s.io/examples/application/zookeeper/zookeeper.yaml ``` This creates the zk StatefulSet object, but the other API objects in the manifest are not modified because they already exist. Watch the StatefulSet controller recreate the StatefulSet's Pods. Bounded code example (external data; do not execute automatically): ```shell kubectl get pods -w -l app=zk ``` Once the zk-2 Pod is Running and Ready, use CTRL-C to terminate kubectl. … Attribution: Adapted from Kubernetes Documentation under CC-BY-4.0. Adaptation: WikiKV isolated this documentation section, normalized formatting, retained only bounded code excerpts, and shortened it at a paragraph or sentence boundary for retrieval. Verify version-sensitive details at the source.