Graceful shutdown
You can configure the graceful shutdown as described in Graceful shutdown.
Servers
As a default, ZooKeeper servers have 2 minutes to shut down gracefully.
The ZooKeeper server process will receive a SIGTERM signal when Kubernetes wants to terminate the Pod.
After the graceful shutdown timeout runs out, and the process still didn’t exit, Kubernetes will issue a SIGKILL signal.
This is equivalent to executing the bin/zkServer.sh stop command, which internally executes kill <zookeeper-pid> (code).
However, there is no acknowledge message in the log indicating a graceful shutdown.