error while starting kafka broker

Question

I was able to successfully set up zookeeper and one kafka broker yesterday. Everything worked as expected. I shut down kafka (ctrl + c) and then zookeeper.

Today I started zookeeper and when I started kafka (bin/kafka-server-start.sh config/server0.properties), I get the following error. I tried various remedies suggested (removing completely my kafka installation and doing it again from scratch). Still I get same error.

[2016-09-28 16:15:55,895] FATAL Fatal error during KafkaServerStartable startup. Prepare to shutdown (kafka.server.KafkaServerStartable)
java.lang.RuntimeException: A broker is already registered on the path /brokers/ids/0. 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.
        at kafka.utils.ZkUtils.registerBrokerInZk(ZkUtils.scala:305)
        at kafka.utils.ZkUtils.registerBrokerInZk(ZkUtils.scala:291)
        at kafka.server.KafkaHealthcheck.register(KafkaHealthcheck.scala:70)
        at kafka.server.KafkaHealthcheck.startup(KafkaHealthcheck.scala:51)
        at kafka.server.KafkaServer.startup(KafkaServer.scala:244)
        at kafka.server.KafkaServerStartable.startup(KafkaServerStartable.scala:37)
        at kafka.Kafka$.main(Kafka.scala:67)
        at kafka.Kafka.main(Kafka.scala)
[2016-09-28 16:15:55,896] INFO [Kafka Server 0], shutting down (kafka.server.KafkaServer)

All set up in mac

Answer 1

I came across the same issue and there are 2 ways to go about it

1. [Recommended] You need to clean up the broker ids in the zookeeper path /brokers/ids/[]. Use the zk-cli tool delete command to clean up the paths. Start your brokers and verify it registers with the coordinator.
2. The other way of resolving this is to change your broker-id from kafka server config and restarting the broker. However, this would corrupt your partitions and data is not recommended