Nick Howard created KAFKA-379: --------------------------------- Summary: TopicCount.constructTopicCount isn't thread-safe Key: KAFKA-379 URL: https://issues.apache.org/jira/browse/KAFKA-379 Project: Kafka Issue Type: Bug Components: clients Affects Versions: 0.7, 0.8 Reporter: Nick Howard
TopicCount uses scala.util.parsing.json.JSON, which isn't thread-safe https://issues.scala-lang.org/browse/SI-4929 If you have multiple consumers within the same JVM, and they all rebalance at the same time, you can get errors like the following: [...] kafka.consumer.TopicCount$.constructTopicCount:39] ERROR: error parsing consumer json string [...] java.lang.NullPointerException at scala.util.parsing.combinator.Parsers$NoSuccess.<init>(Parsers.scala:131) at scala.util.parsing.combinator.Parsers$Failure.<init>(Parsers.scala:158) at scala.util.parsing.combinator.Parsers$$anonfun$acceptIf$1.apply(Parsers.scala:489) ... at scala.util.parsing.combinator.Parsers$$anon$2.apply(Parsers.scala:742) at scala.util.parsing.json.JSON$.parseRaw(JSON.scala:71) at scala.util.parsing.json.JSON$.parseFull(JSON.scala:85) at kafka.consumer.TopicCount$.constructTopicCount(TopicCount.scala:32) at kafka.consumer.ZookeeperConsumerConnector$ZKRebalancerListener.kafka$consumer$ZookeeperConsumerConnector$ZKRebalancerListener$$getTopicCount(ZookeeperConsumerConnector.scala:422) at kafka.consumer.ZookeeperConsumerConnector$ZKRebalancerListener.kafka$consumer$ZookeeperConsumerConnector$ZKRebalancerListener$$rebalance(ZookeeperConsumerConnector.scala:460) at kafka.consumer.ZookeeperConsumerConnector$ZKRebalancerListener$$anonfun$syncedRebalance$1.apply$mcVI$sp(ZookeeperConsumerConnector.scala:437) at scala.collection.immutable.Range$ByOne$class.foreach$mVc$sp(Range.scala:282) at scala.collection.immutable.Range$$anon$2.foreach$mVc$sp(Range.scala:265) at kafka.consumer.ZookeeperConsumerConnector$ZKRebalancerListener.syncedRebalance(ZookeeperConsumerConnector.scala:433) at kafka.consumer.ZookeeperConsumerConnector$ZKRebalancerListener.handleChildChange(ZookeeperConsumerConnector.scala:375) at org.I0Itec.zkclient.ZkClient$7.run(ZkClient.java:568) at org.I0Itec.zkclient.ZkEventThread.run(ZkEventThread.java:71) I ran into this on 0.7.0, but the code in trunk appears to be vulnerable to the same issue. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira