New error code STALE_BROKER_EPOCH (77) and a new type of exception StaleBrokerEpochException will be added. This error is used in the following scenario:
- When a broker sees a LeaderAndIsrRequest/UpdateMetadataRequest/StopReplicaRequest with outdated broker epoch, it will respond back with STALE_BROKER_EPOCH error. The controller will not resend the request.
- When the controller sees a ControlledShutdownRequest with outdated broker epoch, it will respond back with STALE_BROKER_EPOCH error. If the broker gets quickly restarted, it will no see the error response since the channel has already been closed during broker shutdown. If the broker just gets disconnected from zookeeper and re-connect during controlled shutdown, it will retry to send the ControlledShutdownRequest with newer broker epoch to controller.
Broker Registration in Zookeeper