Hi, First of all, I am new to Kafka and more of a user than a developer. I will try to clarify things as much as possible though.
We are using Kafka as a message system for our apps and works nicely in our SaaS cluster. I am trying to make the apps also work on a single node for demo purposes. I set up Zookeeper, Kafka and our apps on a node and things were ok until rebooting the node. After that I see the following messages in Kafka log: [2014-10-22 16:37:22,206] INFO [Controller 0]: Controller starting up (kafka.controller.KafkaController) [2014-10-22 16:37:22,419] INFO [Controller 0]: Controller startup complete (kafka.controller.KafkaController) [2014-10-22 16:37:22,554] INFO conflict in /brokers/ids/0 data: {"jmx_port":-1,"timestamp":"1413995842465","host":"ip-10-91-142-54.eu-west-1.compute.internal","version":1,"port":9092} stored data: {"jmx_port":-1,"timestamp":"1413994171579","host":"ip-10-91-142-54.eu-west-1.compute.internal","version":1,"port":9092} (kafka.utils.ZkUtils$) [2014-10-22 16:37:22,736] INFO I wrote this conflicted ephemeral node [{"jmx_port":-1,"timestamp":"1413995842465","host":"ip-10-91-142-54.eu-west-1.compute.internal","version":1,"port":9092}] at /brokers/ids/0 a while back in a different session, hence I will backoff for this node to be deleted by Zookeeper and retry (kafka.utils.ZkUtils$) [2014-10-22 16:37:25,010] ERROR Error handling event ZkEvent[Data of /controller changed sent to kafka.server.ZookeeperLeaderElector$LeaderChangeListener@a6af882] (org.I0Itec.zkclient.ZkEventThread) java.lang.IllegalStateException: Kafka scheduler has not been started at kafka.utils.KafkaScheduler.ensureStarted(KafkaScheduler.scala:114) at kafka.utils.KafkaScheduler.shutdown(KafkaScheduler.scala:86) at kafka.controller.KafkaController.onControllerResignation(KafkaController.scala:350) at kafka.controller.KafkaController$$anonfun$2.apply$mcV$sp(KafkaController.scala:162) at kafka.server.ZookeeperLeaderElector$LeaderChangeListener$$anonfun$handleDataDeleted$1.apply$mcZ$sp(ZookeeperLeaderElector.scala:138) at kafka.server.ZookeeperLeaderElector$LeaderChangeListener$$anonfun$handleDataDeleted$1.apply(ZookeeperLeaderElector.scala:134) at kafka.server.ZookeeperLeaderElector$LeaderChangeListener$$anonfun$handleDataDeleted$1.apply(ZookeeperLeaderElector.scala:134) at kafka.utils.Utils$.inLock(Utils.scala:535) at kafka.server.ZookeeperLeaderElector$LeaderChangeListener.handleDataDeleted(ZookeeperLeaderElector.scala:134) at org.I0Itec.zkclient.ZkClient$6.run(ZkClient.java:549) at org.I0Itec.zkclient.ZkEventThread.run(ZkEventThread.java:71) [2014-10-22 16:37:28,757] INFO Registered broker 0 at path /brokers/ids/0 with address ip-10-91-142-54.eu-west-1.compute.internal:9092. (kafka.utils.ZkUtils$) [2014-10-22 16:37:28,849] INFO [Kafka Server 0], started (kafka.server.KafkaServer) [2014-10-22 16:38:56,718] INFO Closing socket connection to /127.0.0.1. (kafka.network.Processor) [2014-10-22 16:38:56,850] INFO Closing socket connection to /127.0.0.1. (kafka.network.Processor) [2014-10-22 16:38:56,985] INFO Closing socket connection to /127.0.0.1. (kafka.network.Processor) The last log line repeats forever and is correlated with errors on the app side. Restarting Kafka fixes the errors. I am using Kafka 0.8.2 from github to avoid https://issues.apache.org/jira/browse/KAFKA-1451. Does anyone have any idea why this happens and how it can be fixed? Thanks, Ciprian -- Performance Monitoring * Log Analytics * Search Analytics Solr & Elasticsearch Support * http://sematext.com/