After executing PreferredReplicaLeaderElectionCommand on broker instance,
we observed one of the consumers cannot find the leadership and stopped
consuming. The following exception is all over the log file and it appears
that the consumer cannot recover from it:
2014-10-29 00:53:30,492 WARN
surorouter-logsummary_surorouter-logsummary-i-eaef7107-1413327811303-4afb7b23-leader-finder-thread
ConsumerFetcherManager$LeaderFinderThread -
[surorouter-logsummary_surorouter-logsummary-i-eaef7107-1413327811303-4afb7b23-leader-finder-thread],
Failed to find leader for Set([nf_errors_log,28], [nf_errors_log,29])
java.lang.NullPointerException
at org.I0Itec.zkclient.ZkConnection.getChildren(ZkConnection.java:99)
at org.I0Itec.zkclient.ZkClient$2.call(ZkClient.java:416)
at org.I0Itec.zkclient.ZkClient$2.call(ZkClient.java:413)
at org.I0Itec.zkclient.ZkClient.retryUntilConnected(ZkClient.java:675)
at org.I0Itec.zkclient.ZkClient.getChildren(ZkClient.java:413)
at org.I0Itec.zkclient.ZkClient.getChildren(ZkClient.java:409)
at kafka.utils.ZkUtils$.getChildrenParentMayNotExist(ZkUtils.scala:487)
at kafka.utils.ZkUtils$.getAllBrokersInCluster(ZkUtils.scala:84)
at
kafka.consumer.ConsumerFetcherManager$LeaderFinderThread.doWork(ConsumerFetcherManager.scala:65)
at kafka.utils.ShutdownableThread.run(ShutdownableThread.scala:51)
Except for this instance, other consumer instances are fine. Is there
a workaround? Should we report it as a bug?
Thanks,
Allen
