Konstantine Karantasis created KAFKA-7194: ---------------------------------------------
Summary: Error deserializing assignment after rebalance Key: KAFKA-7194 URL: https://issues.apache.org/jira/browse/KAFKA-7194 Project: Kafka Issue Type: Bug Reporter: Konstantine Karantasis Assignee: Jason Gustafson A simple sink connector task is failing in a test with the following exception: {noformat} [2018-07-02 12:31:13,200] ERROR WorkerSinkTask{id=verifiable-sink-0} Task threw an uncaught and unrecoverable exception (org.apache.kafka.connect.runtime.WorkerTask) org.apache.kafka.common.protocol.types.SchemaException: Error reading field 'version': java.nio.BufferUnderflowException at org.apache.kafka.common.protocol.types.Schema.read(Schema.java:77) at org.apache.kafka.clients.consumer.internals.ConsumerProtocol.deserializeAssignment(ConsumerProtocol.java:105) at org.apache.kafka.clients.consumer.internals.ConsumerCoordinator.onJoinComplete(ConsumerCoordinator.java:243) at org.apache.kafka.clients.consumer.internals.AbstractCoordinator.joinGroupIfNeeded(AbstractCoordinator.java:421) at org.apache.kafka.clients.consumer.internals.AbstractCoordinator.ensureActiveGroup(AbstractCoordinator.java:353) at org.apache.kafka.clients.consumer.internals.AbstractCoordinator.ensureActiveGroup(AbstractCoordinator.java:338) at org.apache.kafka.clients.consumer.internals.ConsumerCoordinator.poll(ConsumerCoordinator.java:333) at org.apache.kafka.clients.consumer.KafkaConsumer.updateAssignmentMetadataIfNeeded(KafkaConsumer.java:1218) at org.apache.kafka.clients.consumer.KafkaConsumer.poll(KafkaConsumer.java:1181) at org.apache.kafka.clients.consumer.KafkaConsumer.poll(KafkaConsumer.java:1115) at org.apache.kafka.connect.runtime.WorkerSinkTask.pollConsumer(WorkerSinkTask.java:444) at org.apache.kafka.connect.runtime.WorkerSinkTask.poll(WorkerSinkTask.java:317) at org.apache.kafka.connect.runtime.WorkerSinkTask.iteration(WorkerSinkTask.java:225) at org.apache.kafka.connect.runtime.WorkerSinkTask.execute(WorkerSinkTask.java:193) at org.apache.kafka.connect.runtime.WorkerTask.doRun(WorkerTask.java:175) at org.apache.kafka.connect.runtime.WorkerTask.run(WorkerTask.java:219) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at java.lang.Thread.run(Thread.java:748){noformat} After dumping the consumer offsets on the partition that this consumer group is writing with: {noformat} bin/kafka-dump-log.sh --offsets-decoder --files ./00000000000000000000.log {noformat} we get: {noformat} Dumping ./00000000000000000000.log Starting offset: 0 offset: 0 position: 0 CreateTime: 1530534673177 isvalid: true keysize: 27 valuesize: 217 magic: 2 compresscodec: NONE producerId: -1 producerEpoch: -1 sequence: -1 isTransactional: false headerKeys: [] key: {"metadata":"connect-verifiable-sink"} payload: {"protocolType":"consumer","protocol":"range","generationId":1,"assignment":"{consumer-4-bad84955-e702-44fe-a018-677bd3b3a9d4=[test-0]}"} offset: 1 position: 314 CreateTime: 1530534673206 isvalid: true keysize: 27 valuesize: 32 magic: 2 compresscodec: NONE producerId: -1 producerEpoch: -1 sequence: -1 isTransactional: false headerKeys: [] key: {"metadata":"connect-verifiable-sink"} payload: {"protocolType":"consumer","protocol":null,"generationId":2,"assignment":"{}"}{noformat} Since the broker seems to send a non-empty response to the consumer, there's a chance that the response buffer is consumed more than once at some point when parsing the response in the client. Here's what the kafka-request.log shows it sends to the client with the `SYNC_GROUP` response that throws the error: {noformat} [2018-07-02 12:31:13,185] DEBUG Completed request:RequestHeader(apiKey=SYNC_GROUP, apiVersion=2, clientId=consumer-4, correlationId=5) -- {group_id=connect-verifiable-sink,generation_id=1,member_id=consumer-4-bad84955-e702-44fe-a018-677bd3b3a9d4,group_assignment=[{member_id=consumer-4-bad84955-e702-44fe-a018-677bd3b3a9d4,member_assignment=java.nio.HeapByteBuffer[pos=0 lim=24 cap=24]}]},response:{throttle_time_ms=0,error_code=0,member_assignment=java.nio.HeapByteBuffer[pos=0 lim=24 cap=24]} from connection 172.31.40.44:9092-172.31.35.189:49191-25;totalTime:8.904,requestQueueTime:0.063,localTime:8.558,remoteTime:0.0,throttleTime:0.03,responseQueueTime:0.037,sendTime:0.245,securityProtocol:PLAINTEXT,principal:User:ANONYMOUS,listener:PLAINTEXT (kafka.request.logger){noformat} -- This message was sent by Atlassian JIRA (v7.6.3#76005)