Hi Are you using the JDBC connector? Can you share with me the command and configuration that you were running?
Thanks, Liquan On Wed, Mar 23, 2016 at 8:36 AM, Aleksandar Pejakovic <a.pejako...@levi9.com > wrote: > Hi, > > > I have created Confluent Connect (http://docs.confluent.io/2.0.1/connect/?) > sink and source tasks. While working in standalone mode there are no > errrors or exceptions. > > > But, when i start tasks in distributed mode i get NullPointerException > while OffsetStorageWriter is executing doFlush() method. > > Full stack trace: > > > ERROR Unhandled exception when committing > WorkerSourceTask{id=distributed-s3-source-0}: > (org.apache.kafka.connect.runtime.SourceTaskOffsetCommitter:118) > java.lang.NullPointerException > at > org.apache.kafka.connect.storage.KafkaOffsetBackingStore.set(KafkaOffsetBackingStore.java:122) > at > org.apache.kafka.connect.storage.OffsetStorageWriter.doFlush(OffsetStorageWriter.java:161) > at > org.apache.kafka.connect.runtime.WorkerSourceTask.commitOffsets(WorkerSourceTask.java:267) > at > org.apache.kafka.connect.runtime.SourceTaskOffsetCommitter.commit(SourceTaskOffsetCommitter.java:110) > at > org.apache.kafka.connect.runtime.SourceTaskOffsetCommitter$1.run(SourceTaskOffsetCommitter.java:76) > at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) > at java.util.concurrent.FutureTask.run(FutureTask.java:266) > at > java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180) > at > java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293) > at > java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) > at > java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) > at java.lang.Thread.run(Thread.java:745) > > > After a closer look i have determined that in KafkaOffsetBackingStore in > set() method, parameter [final Map<ByteBuffer, ByteBuffer> values] is null, > therefore next line: > > - SetCallbackFuture producerCallback = new > SetCallbackFuture(values.size(), callback); throws exception. > > After that exception sink and source tasks continue working without any > problems. > When kafka tries to do another flush, it throws following exception: > > ERROR Invalid call to OffsetStorageWriter flush() while already flushing, > the framework should not allow this > (org.apache.kafka.connect.storage.OffsetStorageWriter:108) > [2016-03-23 14:57:33,220] ERROR Unhandled exception when committing > WorkerSourceTask{id=distributed-s3-source-0}: > (org.apache.kafka.connect.runtime.SourceTaskOffsetCommitter:118) > org.apache.kafka.connect.errors.ConnectException: OffsetStorageWriter is > already flushing > at > org.apache.kafka.connect.storage.OffsetStorageWriter.beginFlush(OffsetStorageWriter.java:110) > at > org.apache.kafka.connect.runtime.WorkerSourceTask.commitOffsets(WorkerSourceTask.java:227) > at > org.apache.kafka.connect.runtime.SourceTaskOffsetCommitter.commit(SourceTaskOffsetCommitter.java:110) > at > org.apache.kafka.connect.runtime.SourceTaskOffsetCommitter$1.run(SourceTaskOffsetCommitter.java:76) > at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) > at java.util.concurrent.FutureTask.run(FutureTask.java:266) > at > java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180) > at > java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293) > at > java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) > at > java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) > at java.lang.Thread.run(Thread.java:745) > > Does anyone know how to fix this exception? > > > I am using confluent-2.0.1 with kafka-9.0.1-cp1. > > > > > -- Liquan Pei Software Engineer, Confluent Inc
