Sam, Please could you send around the entire stack trace for that exception ? It means that the consumer couldn't complete a rebalancing operation and it is possible that the consumer is not pulling all the data for the requested topics.
Thanks, Neha On Tue, Jul 17, 2012 at 1:29 PM, Sam William <sa...@stumbleupon.com> wrote: > > On Mar 20, 2012, at 8:49 AM, Neha Narkhede wrote: > > > Peter, > > > >>> If this exception is thrown, will the consumer the intelligently wait > for the rebalancing to complete? and then resume consumption? > > > > If this exception is thrown, it means that the consumer has failed the > > current rebalancing attempt and will try only when one of the > > following happens - > > > > 1. New partitions are added to the topic it is consuming > > 2. Existing partitions become unavailable > > 3. New consumer instances are brought up for the consumer group it > belongs to > > 4. Existing consumer instances die for the consumer group it belongs to > > > > Until that, the consumer is not fully functional. So, this particular > > exception should be monitored and the consumer instance should be > > restarted. > > > > Having said that, it is pretty rare for the consumer to run out of > > rebalancing attempts. One of the common causes is using zookeeper > > 3.3.3 which causes older ephemeral nodes to be retained. > > Which version of Kafka are you using ? > > Would you mind attaching the entire log for the consumer. It will help > > us debug the cause of this exception and see if it is an actual bug. > > > > Thanks, > > Neha > > > > > > > Neha, > I see this exception > > 2012-07-17 12:58:12,238 ERROR > [ZkClient-EventThread-17-11.zookeeper.,12.zookeeper.,13.zookeeper.,14.zookeeper.,16.zookeeper./kafka] > zkclient.ZkEventThread Error handling event ZkEvent[Children of > /consumers/live-event-sense-new8/ids changed sent to > kafka.consumer.ZookeeperConsumerConnector$ZKRebalancerListener@6d9dd520] > java.lang.RuntimeException: > live-event-sense-new8_sv4r25s49-1342554132312-c04abfef can't rebalance > after 4 retires > > > occurring very often. I use ZK 3.4.3. Im not handling/monitoring this > exception . The consumer seems to continue just fine after this happens. I > do not see any on the 4 conditions you mentioned happening. Am I missing > something ? > > Thanks, > Sam > > > > > > > > > > > > > > > > On Tue, Mar 20, 2012 at 2:42 AM, Peter Thygesen <pt.activ...@gmail.com> > wrote: > >> When I shutdown my consumer with crtl-c and tries to restart it quickly > >> afterwards, I usually get ConsumerRebalanceFailedException (see below). > The > >> application then seems to hang.. or at least I'm sure if it is running > any > >> more.. If this exception is thrown, will the consumer the intelligently > >> wait for the rebalancing to complete? and then resume consumption? > >> > >> I found a page > https://cwiki.apache.org/KAFKA/consumer-co-ordinator.htmlthat > >> describes something about Consumer Co-ordinator.. according to this > >> the consumer > >> group remains in this state until the next rebalancing attempt is > >> triggered. But when is it triggered? > >> > >> Could a shutdown hock with a consumer.commitOffsets help? > >> Does the consumer.shutdown implicit commitOffsets? > >> > >> > >> Exception in thread "main" > kafka.common.ConsumerRebalanceFailedException: > >> contentItem-consumer-group-1_cphhdfs01node09-1332175323213-e6a3010f > can't > >> rebalance after 4 retries > >> at > >> > kafka.consumer.ZookeeperConsumerConnector$ZKRebalancerListener.syncedRebalance(ZookeeperConsumerConnector.scala:467) > >> at > >> > kafka.consumer.ZookeeperConsumerConnector.consume(ZookeeperConsumerConnector.scala:204) > >> at > >> > kafka.javaapi.consumer.ZookeeperConsumerConnector.createMessageStreams(ZookeeperConsumerConnector.scala:75) > >> at > >> > kafka.javaapi.consumer.ZookeeperConsumerConnector.createMessageStreams(ZookeeperConsumerConnector.scala:89) > >> at > >> > com.infopaq.research.repository.uima.ContentItemClient.consume(ContentItemClient.java:75) > >> at > >> > com.infopaq.research.repository.uima.ContentItemClient.main(ContentItemClient.java:111) > >> > >> > >> Brgds, > >> Peter Thygesen > >> > >> BTW: Great work, very interesting project. > > Sam William > sa...@stumbleupon.com > > > >
