We had an issue last week when kafka cluster reported under replicated partitions for quite a while but there were no brokers down. All the brokers were reporting unknownException on Broker 1. When checked broker 1 logs, it just reported below errors(NotAssignedReplicaException) continuously. Issue got resolved after bouncing broker 1. Think this exception comes when Controller issues StopReplicaRequest to broker 1 and it is in the process of leader election. But what is spooky is that this exception was reported more than 20 minutes by the broker and it was chocking entire ingestion(totally 10 brokers). Unfortunately I don't have the controller logs to debug. Any pointers here? We are using 0.8.2.1
ERROR [2016-07-07 11:45:09,248] [kafka-request-handler-1][] kafka.server.KafkaApis - [KafkaApi-1] error when handling request Name: FetchRequest; Version: 0; CorrelationId: 1890972; ClientId: ReplicaFetcherThread-2-1; ReplicaId: 2; MaxWait: 500 ms; MinBytes: 1 bytes; RequestInfo: <value> kafka.common.NotAssignedReplicaException: Leader 1 failed to record follower 2's position 20240372 since the replica is not recognized to be one of the assigned replicas 1,5,6 for partition [<topic>,1] at kafka.server.ReplicaManager.updateReplicaLEOAndPartitionHW(ReplicaManager.scala:574) at kafka.server.KafkaApis$$anonfun$recordFollowerLogEndOffsets$2.apply(KafkaApis.scala:388) at kafka.server.KafkaApis$$anonfun$recordFollowerLogEndOffsets$2.apply(KafkaApis.scala:386) at scala.collection.MapLike$MappedValues$$anonfun$foreach$3.apply(MapLike.scala:245) at scala.collection.MapLike$MappedValues$$anonfun$foreach$3.apply(MapLike.scala:245) at scala.collection.TraversableLike$WithFilter$$anonfun$foreach$1.apply(TraversableLike.scala:778) at scala.collection.immutable.HashMap$HashMap1.foreach(HashMap.scala:221) at scala.collection.immutable.HashMap$HashTrieMap.foreach(HashMap.scala:428) at scala.collection.immutable.HashMap$HashTrieMap.foreach(HashMap.scala:428) at scala.collection.TraversableLike$WithFilter.foreach(TraversableLike.scala:777) at scala.collection.MapLike$MappedValues.foreach(MapLike.scala:245) at kafka.server.KafkaApis.recordFollowerLogEndOffsets(KafkaApis.scala:386) at kafka.server.KafkaApis.handleFetchRequest(KafkaApis.scala:351) at kafka.server.KafkaApis.handle(KafkaApis.scala:60) at kafka.server.KafkaRequestHandler.run(KafkaRequestHandler.scala:59) at java.lang.Thread.run(Thread.java:745) -- Regards, Gokul.M