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  1. Kafka
  2. KAFKA-4131

Multiple Regex KStream-Consumers cause Null pointer exception in addRawRecords in RecordQueue class

    Details

    • Type: Bug
    • Status: Resolved
    • Priority: Major
    • Resolution: Fixed
    • Affects Version/s: 0.10.1.0
    • Fix Version/s: 0.10.1.0
    • Component/s: streams
    • Labels:
      None
    • Environment:
      Servers: Confluent Distribution 3.0.0 (i.e. kafka 0.10.0 release)
      Client: Kafka-streams and Kafka-client... commit: 6fb33afff976e467bfa8e0b29eb827
      70a2a3aaec
    • Flags:
      Important

      Description

      When you start two consumer processes with a regex topic (with 2 or more
      partitions for the matching topics), the second (i.e. nonleader) consumer
      will fail with a null pointer exception.

      Exception in thread "StreamThread-4" java.lang.NullPointerException
      at org.apache.kafka.streams.processor.internals.
      RecordQueue.addRawRecords(RecordQueue.java:78)
      at org.apache.kafka.streams.processor.internals.
      PartitionGroup.addRawRecords(PartitionGroup.java:117)
      at org.apache.kafka.streams.processor.internals.
      StreamTask.addRecords(StreamTask.java:139)
      at org.apache.kafka.streams.processor.internals.
      StreamThread.runLoop(StreamThread.java:299)
      at org.apache.kafka.streams.processor.internals.
      StreamThread.run(StreamThread.java:208)

      The issue may be in the TopologyBuilder line 832:
      String[] topics = (sourceNodeFactory.pattern != null) ?
      sourceNodeFactory.getTopics(subscriptionUpdates.getUpdates()) :
      sourceNodeFactory.getTopics();

      Because the 2nd consumer joins as a follower, “getUpdates” returns an
      empty collection and the regular expression doesn’t get applied to any
      topics.

      Steps to Reproduce:
      1.) Create at least two topics with at least 2 partitions each. And start sending messages to them.
      2.) Start a single threaded Regex KStream-Consumer (i.e. becomes the leader)
      3) Start a new instance of this consumer (i.e. it should receive some of the partitions)

      The second consumer will die with the above exception.

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              • Assignee:
                bbejeck Bill Bejeck
                Reporter:
                djchooy David J. Garcia
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                Dates

                • Created:
                  Updated:
                  Resolved: