...

> bin/kafka-quorum.sh --alter --voters 0,3,4
CurrentVoters:			[0, 1, 2]
TargetVoters:			[0, 3, 4]

Once a reassignment has been submitted, users can use one of the --describe options to monitor progress

Client Interactions

Since this specific quorum implementation is only to be used by Kafka internally, we do not need to add new public protocols for clients. More specifically, the leader of the quorum would act as the controller of the cluster, and any client requests that requires updating the metadata (previously stored in ZK) would be interpreted as appending new record(s) to the quorum's internal log.

...