>From the broker log:
INFO Reconnect due to socket error: (kafka.consumer.SimpleConsumer) java.nio.channels.ClosedChannelException at kafka.network.BlockingChannel.send(BlockingChannel.scala:89) at kafka.consumer.SimpleConsumer.liftedTree1$1(SimpleConsumer.scala:72) at kafka.consumer.SimpleConsumer.kafka$consumer$SimpleConsumer$$sendRequest(SimpleConsumer.scala:71) at kafka.consumer.SimpleConsumer.getOffsetsBefore(SimpleConsumer.scala:125) at kafka.tools.ConsumerOffsetChecker$.kafka$tools$ConsumerOffsetChecker$$processPartition(ConsumerOffsetChecker.scala:72) at kafka.tools.ConsumerOffsetChecker$$anonfun$kafka$tools$ConsumerOffsetChecker$$processTopic$1.apply$mcVI$sp(ConsumerOffsetChecker.scala:90) at kafka.tools.ConsumerOffsetChecker$$anonfun$kafka$tools$ConsumerOffsetChecker$$processTopic$1.apply(ConsumerOffsetChecker.scala:90) at kafka.tools.ConsumerOffsetChecker$$anonfun$kafka$tools$ConsumerOffsetChecker$$processTopic$1.apply(ConsumerOffsetChecker.scala:90) at scala.collection.LinearSeqOptimized$class.foreach(LinearSeqOptimized.scala:61) at scala.collection.immutable.List.foreach(List.scala:45) at kafka.tools.ConsumerOffsetChecker$.kafka$tools$ConsumerOffsetChecker$$processTopic(ConsumerOffsetChecker.scala:89) at kafka.tools.ConsumerOffsetChecker$$anonfun$main$3.apply(ConsumerOffsetChecker.scala:154) at kafka.tools.ConsumerOffsetChecker$$anonfun$main$3.apply(ConsumerOffsetChecker.scala:154) at scala.collection.LinearSeqOptimized$class.foreach(LinearSeqOptimized.scala:61) at scala.collection.immutable.List.foreach(List.scala:45) at kafka.tools.ConsumerOffsetChecker$.main(ConsumerOffsetChecker.scala:153) at kafka.tools.ConsumerOffsetChecker.main(ConsumerOffsetChecker.scala) On Wed, Sep 11, 2013 at 10:11 PM, Jun Rao <jun...@gmail.com> wrote: > This means the broker somehow closed the socket connection. Anything in the > broker log around the same time? > > Thanks, > > Jun > > > On Wed, Sep 11, 2013 at 6:07 PM, prashant amar <amasin...@gmail.com> > wrote: > > > Also noticed another issue > > > > Specified below is the current configuration > > > > Topic1 -> n Partitions -> 2 Consumer Groups (gr1 and gr2) > > Topic2 -> n Partitions -> 2 Consumer Groups (gr1 and gr2) > > > > Notice that I have used the same naming convention on the consumer group > > set i.e. 'gr1' and 'gr2' are consumer groups associated with 2 sets of > > topics. > > > > On calling the *ConsumerOffsetChecker* API, I am receiving a > > ClosedChannelException > > > > (Check Trace Below) > > > > Is there any namespace collision occurring here ? This issue is > > reproducible with the following setup above > > > > > > *bin/kafka-run-class.sh kafka.tools.ConsumerOffsetChecker --group gr2 > > --zkconnect localhost:2181* > > > > > > 2013-09-12 01:01:59,701] INFO Initiating client connection, > > connectString=localhost:2181 sessionTimeout=30000 > > watcher=org.I0Itec.zkclient.ZkClient@3af0ce45 > > (org.apache.zookeeper.ZooKeeper) > > [2013-09-12 01:01:59,724] INFO Opening socket connection to server > > localhost/127.0.0.1:2181 (org.apache.zookeeper.ClientCnxn) > > [2013-09-12 01:01:59,732] INFO Socket connection established to > localhost/ > > 127.0.0.1:2181, initiating session (org.apache.zookeeper.ClientCnxn) > > [2013-09-12 01:01:59,741] INFO Session establishment complete on server > > localhost/127.0.0.1:2181, sessionid = 0x140924380790211, negotiated > > timeout > > = 30000 (org.apache.zookeeper.ClientCnxn) > > [2013-09-12 01:01:59,744] INFO zookeeper state changed (SyncConnected) > > (org.I0Itec.zkclient.ZkClient) > > Group Topic Pid Offset > logSize > > Lag Owner > > gr2 pe1 0 129985 130625 > > 640 none > > gr2 pe1 1 0 0 > > 0 none > > gr2 pe2 0 130493 130493 > > 0 gr2_ip-XXXXXXXXXX-6c6f5d94-0 > > [2013-09-12 01:02:00,514] INFO Reconnect due to socket error: > > (kafka.consumer.SimpleConsumer) > > java.nio.channels.ClosedChannelException > > at kafka.network.BlockingChannel.send(BlockingChannel.scala:89) > > at kafka.consumer.SimpleConsumer.liftedTree1$1(SimpleConsumer.scala:72) > > at > > > > > kafka.consumer.SimpleConsumer.kafka$consumer$SimpleConsumer$$sendRequest(SimpleConsumer.scala:71) > > at > kafka.consumer.SimpleConsumer.getOffsetsBefore(SimpleConsumer.scala:125) > > at > > > > > kafka.tools.ConsumerOffsetChecker$.kafka$tools$ConsumerOffsetChecker$$processPartition(ConsumerOffsetChecker.scala:72) > > at > > > > > kafka.tools.ConsumerOffsetChecker$$anonfun$kafka$tools$ConsumerOffsetChecker$$processTopic$1.apply$mcVI$sp(ConsumerOffsetChecker.scala:90) > > at > > > > > kafka.tools.ConsumerOffsetChecker$$anonfun$kafka$tools$ConsumerOffsetChecker$$processTopic$1.apply(ConsumerOffsetChecker.scala:90) > > at > > > > > kafka.tools.ConsumerOffsetChecker$$anonfun$kafka$tools$ConsumerOffsetChecker$$processTopic$1.apply(ConsumerOffsetChecker.scala:90) > > at > > > > > scala.collection.LinearSeqOptimized$class.foreach(LinearSeqOptimized.scala:61) > > at scala.collection.immutable.List.foreach(List.scala:45) > > at > > > > > kafka.tools.ConsumerOffsetChecker$.kafka$tools$ConsumerOffsetChecker$$processTopic(ConsumerOffsetChecker.scala:89) > > at > > > > > kafka.tools.ConsumerOffsetChecker$$anonfun$main$3.apply(ConsumerOffsetChecker.scala:154) > > at > > > > > kafka.tools.ConsumerOffsetChecker$$anonfun$main$3.apply(ConsumerOffsetChecker.scala:154) > > at > > > > > scala.collection.LinearSeqOptimized$class.foreach(LinearSeqOptimized.scala:61) > > at scala.collection.immutable.List.foreach(List.scala:45) > > at > kafka.tools.ConsumerOffsetChecker$.main(ConsumerOffsetChecker.scala:153) > > at kafka.tools.ConsumerOffsetChecker.main(ConsumerOffsetChecker.scala) > > gr2 pe2 1 0 0 > > 0 gr2_ip-XXXXXXX-6c6f5d94-1 > > [2013-09-12 01:02:00,523] INFO Terminate ZkClient event thread. > > (org.I0Itec.zkclient.ZkEventThread) > > [2013-09-12 01:02:00,526] INFO Session: 0x140924380790211 closed > > (org.apache.zookeeper.ZooKeeper) > > [2013-09-12 01:02:00,526] INFO EventThread shut down > > (org.apache.zookeeper.ClientCnxn) > > > > > > > > > > > > > > > > On Wed, Sep 11, 2013 at 5:46 PM, Neha Narkhede <neha.narkh...@gmail.com> > > wrote: > > > > > I think you are hitting this - > > > > > > > > > https://cwiki.apache.org/confluence/display/KAFKA/FAQ#FAQ-Whysomeoftheconsumersinaconsumergroupneverreceiveanymessage%3F > > > > > > Let us know if we can improve the documentation to make it clearer. > > > > > > Thanks, > > > Neha > > > > > > > > > On Wed, Sep 11, 2013 at 5:28 PM, prashant amar <amasin...@gmail.com> > > > wrote: > > > > > > > Also attempted another pattern where > > > > > > > > 1. Created a topic T with 'n' partitions. > > > > 2. Created a consumer group process with 'n + 1' threads subscribing > > from > > > > topic 'T' with a groupID 'y' > > > > 3. Added another consumer group process with 'n + 1' threads > > subscribing > > > > from same topic 'T' with same groupID 'z' > > > > (Note that 2 and 3 subscribe from same topic but different groups) > > > > > > > > Can a single topic with multiple partitions abetted with multiple > > > consumer > > > > groups increase parallelism is consumption? > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > On Wed, Sep 11, 2013 at 4:48 PM, prashant amar <amasin...@gmail.com> > > > > wrote: > > > > > > > > > A Design Question that needs verification: > > > > > > > > > > 1. Created a topic T with 'n' partitions. > > > > > 2. Created a consumer group process with 'n + 1' threads > subscribing > > > from > > > > > topic 'T' with a groupID 'y' > > > > > 3. Added another consumer group process with 'n + 1' threads > > > subscribing > > > > > from same topic 'T' with same groupID 'y' > > > > > > > > > > On doing so, I noticed that the previous consumer group stops > > consuming > > > > > and the new consumer beings to consume > > > > > > > > > > I was attempting to model on demand parallelization in an event > where > > > an > > > > > consumer group cannot keep up with the events produced. Rather than > > > > > increase the threadpool capacity in the same process, it would make > > > sense > > > > > to distribute the load across multiple processes. > > > > > > > > > > Advice please? > > > > > > > > > > Regards > > > > > Amardeep > > > > > > > > > > > > > > > > > >