FATAL [Kafka Server 1], Fatal error during KafkaServer startup. Prepare to shutdown (kafka.server.KafkaServer) java.lang.RuntimeException: A broker is already registered on the path /brokers/ids/1. This probably indicates that you either have configured a brokerid that is already in use, or else you have shutdown this broker and restarted it faster than the zookeeper timeout so it appears to be re-registering.