The Apache cluster will automatically identify any broker shutdown or failure. In this instance, new leaders for partitions previously handled by that device will be chosen. This can happen as a result of a server failure or even if it is shut down for maintenance or configuration changes. When a server is taken down on purpose, Kafka provides a graceful method for terminating the server rather than killing it.
When a server is switched off :
* To prevent having to undertake any log recovery when Kafka is restarted, it ensures that all of its logs are synced onto a disk. Because log recovery takes time, purposeful restarts can be sped up.
* Prior to shutting down, all partitions for which the server is the leader will be moved to the replicas. The leadership transfer will be faster as a result, and the period each partition is inaccessible will be decreased to a few milliseconds.
