title: Kafka Streams - Rebalancing exception in Kafka 1.0.0
body: <p>In Kafka Streams 1.0.0, we saw a strange error coming my way. My stream app ingest a kafka topic and emit multiple aggregations on different state stores, now the app works on a cluster of 2 nodes, but the moment the third one is added the stream app crashes on all the nodes.</p>
  
  <p>Following is the exception that i get.</p>
  
  <pre><code>2017-12-12 15:32:55 ERROR Kafka010Base:47 - Exception caught in thread c-7-aq32-5648256f-9142-49e2-98c0-da792e6da48e-StreamThread-5
  org.apache.kafka.common.KafkaException: Unexpected error from SyncGroup: The server experienced an unexpected error when processing the request
          at org.apache.kafka.clients.consumer.internals.AbstractCoordinator$SyncGroupResponseHandler.handle(AbstractCoordinator.java:566)
          at org.apache.kafka.clients.consumer.internals.AbstractCoordinator$SyncGroupResponseHandler.handle(AbstractCoordinator.java:539)
          at org.apache.kafka.clients.consumer.internals.AbstractCoordinator$CoordinatorResponseHandler.onSuccess(AbstractCoordinator.java:808)
          at org.apache.kafka.clients.consumer.internals.AbstractCoordinator$CoordinatorResponseHandler.onSuccess(AbstractCoordinator.java:788)
          at org.apache.kafka.clients.consumer.internals.RequestFuture$1.onSuccess(RequestFuture.java:204)
          at org.apache.kafka.clients.consumer.internals.RequestFuture.fireSuccess(RequestFuture.java:167)
          at org.apache.kafka.clients.consumer.internals.RequestFuture.complete(RequestFuture.java:127)
          at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient$RequestFutureCompletionHandler.fireCompletion(ConsumerNetworkClient.java:506)
          at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient.firePendingCompletedRequests(ConsumerNetworkClient.java:353)
          at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient.poll(ConsumerNetworkClient.java:268)
          at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient.poll(ConsumerNetworkClient.java:214)
  </code></pre>
  
  <p>On Taking a look further on brokers, I saw another exception</p>
  
  <pre><code>[2017-12-12 17:28:36,822] INFO [GroupCoordinator 90]: Preparing to rebalance group c-7-aq32 with old generation 25 (__consumer_offsets-39) (kafka.coordinator.group.GroupCoordinator)
  [2017-12-12 17:28:40,500] INFO [GroupCoordinator 90]: Stabilized group c-7-aq32 generation 26 (__consumer_offsets-39) (kafka.coordinator.group.GroupCoordinator)
  [2017-12-12 17:28:42,290] INFO [GroupCoordinator 90]: Assignment received from leader for group c-7-aq32 for generation 26 **(kafka.coordinator.group.GroupCoordinator)
  [2017-12-12 17:28:42,300] ERROR [GroupMetadataManager brokerId=90] Appending metadata message for group c-7-aq32 generation 26 failed due to org.apache.kafka.common.errors.RecordTooLargeException, returning UNKNOWN error code to the client (kafka.coordinator.group.GroupMetadataManager)**
  [2017-12-12 17:28:42,301] INFO [GroupCoordinator 90]: Preparing to rebalance group c-7-aq32 with old generation 26 (__consumer_offsets-39) (kafka.coordinator.group.GroupCoordinator)
  [2017-12-12 17:28:52,301] INFO [GroupCoordinator 90]: Member c-7-aq32-6138ec53-4aff-4596-8f4b-44ae6f5d72da-StreamThread-13-consumer-e0cc0931-0619-4908-82c2-28f7bf9bace9 in group c-7-aq32 has failed, removing it from the group (kafka.coordinator.group.GroupCoordinator)
  </code></pre>
  
  <p>Now, I would need help in understanding why I would be getting RecordTooLargeException. </p>