That's not it either. I just had all my consumers shut down on me with this:
INFO 21:51:13,948 () ZkUtils$ - conflict in /consumers/flurry1/owners/dataLogPaths/1-183 data: flurry1_hs1030-1376964634130-dcc9192a-0 stored data: flurry1_hs1061-1376964609207-4b7f348b-0 INFO 21:51:13,948 () ZookeeperConsumerConnector - flurry1_hs1030-1376964634130-dcc9192a waiting for the partition ownership to be deleted: 1-183 INFO 21:51:13,950 () ZookeeperConsumerConnector - flurry1_hs1030-1376964634130-dcc9192a flurry1_hs1030-1376964634130-dcc9192a-0 successfully owned partition 1-180 for topic dataLogPaths and I've also been seeing: INFO 21:51:15,971 () ZookeeperConsumerConnector - flurry1_hs1030-1376964634130-dcc9192a begin rebalancing consumer flurry1_hs1030-1376964634130-dcc9192a try #3 INFO 21:51:16,038 () ZookeeperConsumerConnector - flurry1_hs1030-1376964634130-dcc9192a exception during rebalance org.I0Itec.zkclient.exception.ZkNoNodeException: org.apache.zookeeper.KeeperException$NoNodeException: KeeperErrorCode = NoNode for /consumers/flurry1/ids/flurry1_hs676-1376964612747-6f532caa at org.I0Itec.zkclient.exception.ZkException.create(ZkException.java:47) at org.I0Itec.zkclient.ZkClient.retryUntilConnected(ZkClient.java:685) at org.I0Itec.zkclient.ZkClient.readData(ZkClient.java:766) at org.I0Itec.zkclient.ZkClient.readData(ZkClient.java:761) at org.I0Itec.zkclient.ZkClient.readData(ZkClient.java:750) at org.I0Itec.zkclient.ZkClient.readData(ZkClient.java:744) at kafka.utils.ZkUtils$.readData(ZkUtils.scala:162) at kafka.consumer.TopicCount$.constructTopicCount(TopicCount.scala:66) at kafka.utils.ZkUtils$$anonfun$getConsumersPerTopic$1.apply(ZkUtils.scala:259) at kafka.utils.ZkUtils$$anonfun$getConsumersPerTopic$1.apply(ZkUtils.scala:258) at scala.collection.Iterator$class.foreach(Iterator.scala:631) at scala.collection.JavaConversions$JIteratorWrapper.foreach(JavaConversions.scala:474) at scala.collection.IterableLike$class.foreach(IterableLike.scala:79) at scala.collection.JavaConversions$JListWrapper.foreach(JavaConversions.scala:521) at kafka.utils.ZkUtils$.getConsumersPerTopic(ZkUtils.scala:258) at kafka.consumer.ZookeeperConsumerConnector$ZKRebalancerListener.kafka$consumer$ZookeeperConsumerConnector$ZKRebalancerListener$$rebalance(ZookeeperConsumerConnector.scala:478) at kafka.consumer.ZookeeperConsumerConnector$ZKRebalancerListener$$anonfun$syncedRebalance$1.apply$mcVI$sp(ZookeeperConsumerConnector.scala:449) at scala.collection.immutable.Range$ByOne$class.foreach$mVc$sp(Range.scala:285) at scala.collection.immutable.Range$$anon$2.foreach$mVc$sp(Range.scala:265) at kafka.consumer.ZookeeperConsumerConnector$ZKRebalancerListener.syncedRebalance(ZookeeperConsumerConnector.scala:444) at kafka.consumer.ZookeeperConsumerConnector$ZKRebalancerListener$$anon$1.run(ZookeeperConsumerConnector.scala:401) Caused by: org.apache.zookeeper.KeeperException$NoNodeException: KeeperErrorCode = NoNode for /consumers/flurry1/ids/flurry1_hs676-1376964612747-6f532caa at org.apache.zookeeper.KeeperException.create(KeeperException.java:111) at org.apache.zookeeper.KeeperException.create(KeeperException.java:51) at org.apache.zookeeper.ZooKeeper.getData(ZooKeeper.java:1151) at org.apache.zookeeper.ZooKeeper.getData(ZooKeeper.java:1180) at org.I0Itec.zkclient.ZkConnection.readData(ZkConnection.java:103) at org.I0Itec.zkclient.ZkClient$9.call(ZkClient.java:770) at org.I0Itec.zkclient.ZkClient$9.call(ZkClient.java:766) at org.I0Itec.zkclient.ZkClient.retryUntilConnected(ZkClient.java:675) ... 19 more INFO 21:51:16,039 () ZookeeperConsumerConnector - flurry1_hs1030-1376964634130-dcc9192a end rebalancing consumer flurry1_hs1030-1376964634130-dcc9192a try #3 any ideas? -- Ian Friedman On Monday, August 19, 2013 at 11:58 PM, Jun Rao wrote: > Any failure/restart of a consumer or a broker can also trigger a rebalance. > > Thanks, > > Jun > > > On Mon, Aug 19, 2013 at 6:00 PM, Ian Friedman <i...@flurry.com > (mailto:i...@flurry.com)> wrote: > > > Jun, I read that FAQ entry you linked, but I am not seeing any Zookeeper > > connection loss in the logs. It's rebalancing multiple times per minute, > > though. Any idea what else could cause this? We're running kafka 0.7.2 on > > approx 400 consumers against a topic with 400 partitions * 3 brokers. > > > > -- > > Ian Friedman > > > > > > On Thursday, August 15, 2013 at 11:52 AM, Jun Rao wrote: > > > > > Yes, during rebalances, messages could be re-delievered since the new > > owner > > > of a partition starts fetching from the last checkpointed offset in ZK. > > > > > > For reasons on why rebalances happen a lot, see > > https://cwiki.apache.org/confluence/display/KAFKA/FAQ#FAQ-Whyaretheremanyrebalancesinmyconsumerlog%3F > > > > > > Thanks, > > > > > > Jun > > > > > > > > > On Thu, Aug 15, 2013 at 8:36 AM, Ian Friedman <i...@flurry.com > > > (mailto:i...@flurry.com) (mailto: > > i...@flurry.com (mailto:i...@flurry.com))> wrote: > > > > > > > It's a simple enough patch, but wouldn't this mean that messages still > > in > > > > process when a rebalance happens could get delivered to another > > > > > > > consumer if > > > > we end up losing the partition? Rebalances seem to happen very > > > > > > > frequently > > > > with a lot of consumers for some reason… And it doesn't seem like a > > > > consumer is guaranteed or likely to retain ownership of a partition > > > > > > > > > > > it's in > > > > the middle of consuming after a rebalance. > > > > > > > > -- > > > > Ian Friedman > > > > > > > > > > > > On Thursday, August 15, 2013 at 10:53 AM, Jun Rao wrote: > > > > > > > > > We are only patching blocker issues in 0.7. 0.8 beta1 has been > > released > > > > and > > > > > most dev effort will be on 0.8 and beyond. That said. This particular > > > > > > > > > > > > case > > > > > is easy to fix. If you can port the patch in > > > > > https://issues.apache.org/jira/browse/KAFKA-919 o the 0.7 branch , > > > > > > > > > > > > > > > > > > > > we > > > > > > > > > > > > > > > > > can > > > > > commit that to the 0.7 branch. > > > > > > > > > > Thanks, > > > > > > > > > > Jun > > > > > > > > > > > > > > > On Wed, Aug 14, 2013 at 9:30 PM, Ian Friedman <i...@flurry.com > > > > > (mailto:i...@flurry.com)(mailto: > > i...@flurry.com (mailto:i...@flurry.com)) (mailto: > > > > i...@flurry.com (mailto:i...@flurry.com))> wrote: > > > > > > > > > > > Ugh. > > > > > > > > > > > > Is there any way to make this work in 0.7, or is transitioning to > > 0.8 > > > > the > > > > > > only way? My operations engineers spent a lot of effort in > > > > > > > > > > > > > > > > > > > > configuring > > > > > > > > > > > > > > > > > and > > > > > > hardening our 0.7 production install, and 0.8 isn't released yet. > > > > > > > > > > > > > > > > > > > > Not > > > > > > > > > > > > > > > > > to > > > > > > mention having to integrate the new client side code. > > > > > > > > > > > > Either way, thanks for all your help Jun. > > > > > > > > > > > > -- > > > > > > Ian Friedman > > > > > > > > > > > > > > > > > > On Thursday, August 15, 2013 at 12:21 AM, Jun Rao wrote: > > > > > > > > > > > > > Yes, this is an issue and has been fixed in 0.8. > > > > > > > > > > > > > > Thanks, > > > > > > > > > > > > > > Jun > > > > > > > > > > > > > > > > > > > > > On Wed, Aug 14, 2013 at 5:21 PM, Ian Friedman <i...@flurry.com > > > > > > > (mailto:i...@flurry.com)(mailto: > > i...@flurry.com (mailto:i...@flurry.com))(mailto: > > > > i...@flurry.com (mailto:i...@flurry.com)) (mailto: > > > > > > i...@flurry.com (mailto:i...@flurry.com))> wrote: > > > > > > > > > > > > > > > Hey guys, > > > > > > > > > > > > > > > > I designed my consumer app (running on 0.7) to run with > > autocommit > > > > off > > > > > > and > > > > > > > > commit manually once it was done processing a record. The > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > intent > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > was so > > > > > > > > that if a consumer died while processing a message, the offset > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > would > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > not be > > > > > > > > committed, and another box would pick up the partition and > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > reprocess > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > the > > > > > > > > message. This seemed to work fine with small numbers of > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > consumers > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > (~10). > > > > > > > > But now that I'm scaling it out, I'm running into a problem > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > where > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > it > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > looks > > > > > > > > like messages that consumers picked up and then errored on are > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > not > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > getting > > > > > > > > processed on another machine. > > > > > > > > > > > > > > > > After investigating the logs and the partition offsets in > > > > zookeeper, I > > > > > > > > found that in ZookeeperConsumerConnector.scala > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > closeFetchersForQueues, > > > > > > > > called during the rebalance process, will commit the offset > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > regardless > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > of > > > > > > > > the autocommit status. So it looks like even if my consumer is > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > in > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > the > > > > > > > > middle of processing a message, the offset will be committed, > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > and > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > even > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > if > > > > > > > > the processing fails, it will never be picked up again. Now > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > that I > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > have a > > > > > > > > lot of consumer nodes, the rebalancer is going off a lot more > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > often > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > and I'm > > > > > > > > running into this constantly. > > > > > > > > > > > > > > > > Were my assumptions faulty? Did I design this wrong? After > > reading > > > > the > > > > > > > > comment in the code I understand that if it didn't commit the > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > offset > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > there, > > > > > > > > the message would just get immediately consumed by whoever > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > ended up > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > owning > > > > > > > > the partition, even if we were in the middle of consuming it > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > elsewhere, and > > > > > > > > we'd get unintentional duplicate delivery. How can I make it > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > work > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > the > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > way > > > > > > > > I've described? Is there any way? > > > > > > > > > > > > > > > > Thanks in advance, > > > > > > > > > > > > > > > > -- > > > > > > > > Ian Friedman > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >