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https://issues.apache.org/jira/browse/KAFKA-8532?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16863468#comment-16863468
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Jun Rao commented on KAFKA-8532:
--------------------------------
[~lbdai3190], thanks for reporting the issue. From the stacktrace, it seems
that the controller-event-thread is blocked on ZooKeeperClient.scala:157, which
corresponds to the following line.
{code:java}
countDownLatch.await()
{code}
So, it doesn't seem that thread was blocked on inReadLock(initializationLock)?
** As you said, normally the wait on countDownLatch shouldn't block since if
the ZK session is expired, the requests should get an error code immediately.
Do you have the stack trace for the ZK event thread? Normally, this is the
thread that unblocks the async ZK requests. I am wondering if that thread is
still alive or is blocked on anything.
The controller-event-thread was processing a RegisterBrokerAndReelect event.
Since this event is only generated during ZK session expiration, it seems
consecutive ZK session expirations have happened. I am not sure if that can
lead to deadlocks though.
> controller-event-thread deadlock with zk-session-expiry-handler0
> ----------------------------------------------------------------
>
> Key: KAFKA-8532
> URL: https://issues.apache.org/jira/browse/KAFKA-8532
> Project: Kafka
> Issue Type: Bug
> Components: core
> Affects Versions: 2.1.1
> Reporter: leibo
> Priority: Blocker
> Attachments: js.log
>
>
> We have observed a serious deadlock between controller-event-thead and
> zk-session-expirey-handle thread. When this issue occurred, it's only one way
> to recovery the kafka cluster is restart kafka server. The follows is the
> jstack log of controller-event-thead and zk-session-expiry-handle thread.
> "zk-session-expiry-handler0" #163089 daemon prio=5 os_prio=0
> tid=0x00007fcc9c010000 nid=0xfb22 waiting on condition [0x00007fcbb01f8000]
> java.lang.Thread.State: WAITING (parking)
> at sun.misc.Unsafe.park(Native Method)
> - parking to wait for <0x00000005ee3f7000> (a
> java.util.concurrent.CountDownLatch$Sync)
> at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
> at
> java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:836)
> at
> java.util.concurrent.locks.AbstractQueuedSynchronizer.doAcquireSharedInterruptibly(AbstractQueuedSynchronizer.java:997)
> at
> java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireSharedInterruptibly(AbstractQueuedSynchronizer.java:1304)
> at java.util.concurrent.CountDownLatch.await(CountDownLatch.java:231) //
> 等待controller-event-thread线程处理expireEvent
> at
> kafka.controller.KafkaController$Expire.waitUntilProcessingStarted(KafkaController.scala:1533)
> at
> kafka.controller.KafkaController$$anon$7.beforeInitializingSession(KafkaController.scala:173)
> at
> kafka.zookeeper.ZooKeeperClient.callBeforeInitializingSession(ZooKeeperClient.scala:408)
> at
> kafka.zookeeper.ZooKeeperClient.$anonfun$reinitialize$1(ZooKeeperClient.scala:374)
> at
> kafka.zookeeper.ZooKeeperClient.$anonfun$reinitialize$1$adapted(ZooKeeperClient.scala:374)
> at kafka.zookeeper.ZooKeeperClient$$Lambda$1473/1823438251.apply(Unknown
> Source)
> at scala.collection.Iterator.foreach(Iterator.scala:937)
> at scala.collection.Iterator.foreach$(Iterator.scala:937)
> at scala.collection.AbstractIterator.foreach(Iterator.scala:1425)
> at scala.collection.MapLike$DefaultValuesIterable.foreach(MapLike.scala:209)
> at kafka.zookeeper.ZooKeeperClient.reinitialize(ZooKeeperClient.scala:374)
> at
> kafka.zookeeper.ZooKeeperClient.$anonfun$scheduleSessionExpiryHandler$1(ZooKeeperClient.scala:428)
> at
> kafka.zookeeper.ZooKeeperClient$$Lambda$1471/701792920.apply$mcV$sp(Unknown
> Source)
> at kafka.utils.KafkaScheduler.$anonfun$schedule$2(KafkaScheduler.scala:114)
> at kafka.utils.KafkaScheduler$$Lambda$198/1048098469.apply$mcV$sp(Unknown
> Source)
> at kafka.utils.CoreUtils$$anon$1.run(CoreUtils.scala:63)
> at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
> at java.util.concurrent.FutureTask.run(FutureTask.java:266)
> at
> java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180)
> at
> java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)
> at
> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
> at
> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
> at java.lang.Thread.run(Thread.java:748)
> Locked ownable synchronizers:
> - <0x0000000661e8d2e0> (a java.util.concurrent.ThreadPoolExecutor$Worker)
> "controller-event-thread" #51 prio=5 os_prio=0 tid=0x00007fceaeec4000
> nid=0x310 waiting on condition [0x00007fccb55c8000]
> java.lang.Thread.State: WAITING (parking)
> at sun.misc.Unsafe.park(Native Method)
> - parking to wait for <0x00000005d1be5a00> (a
> java.util.concurrent.CountDownLatch$Sync)
> at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
> at
> java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:836)
> at
> java.util.concurrent.locks.AbstractQueuedSynchronizer.doAcquireSharedInterruptibly(AbstractQueuedSynchronizer.java:997)
> at
> java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireSharedInterruptibly(AbstractQueuedSynchronizer.java:1304)
> at java.util.concurrent.CountDownLatch.await(CountDownLatch.java:231)
> at kafka.zookeeper.ZooKeeperClient.handleRequests(ZooKeeperClient.scala:157)
> at
> kafka.zk.KafkaZkClient.retryRequestsUntilConnected(KafkaZkClient.scala:1596)
> at
> kafka.zk.KafkaZkClient.kafka$zk$KafkaZkClient$$retryRequestUntilConnected(KafkaZkClient.scala:1589)
> at
> kafka.zk.KafkaZkClient.deletePreferredReplicaElection(KafkaZkClient.scala:989)
> at
> kafka.controller.KafkaController.removePartitionsFromPreferredReplicaElection(KafkaController.scala:873)
> at
> kafka.controller.KafkaController.kafka$controller$KafkaController$$onPreferredReplicaElection(KafkaController.scala:631)
> at
> kafka.controller.KafkaController.onControllerFailover(KafkaController.scala:266)
> at
> kafka.controller.KafkaController.kafka$controller$KafkaController$$elect(KafkaController.scala:1221)
> at
> kafka.controller.KafkaController$Reelect$.process(KafkaController.scala:1508)
> at
> kafka.controller.KafkaController$RegisterBrokerAndReelect$.process(KafkaController.scala:1517)
> at
> kafka.controller.ControllerEventManager$ControllerEventThread.$anonfun$doWork$1(ControllerEventManager.scala:89)
> at
> kafka.controller.ControllerEventManager$ControllerEventThread$$Lambda$362/918424570.apply$mcV$sp(Unknown
> Source)
> at scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:12)
> at kafka.metrics.KafkaTimer.time(KafkaTimer.scala:31)
> at
> kafka.controller.ControllerEventManager$ControllerEventThread.doWork(ControllerEventManager.scala:89)
> at kafka.utils.ShutdownableThread.run(ShutdownableThread.scala:82)
> Locked ownable synchronizers:
> - None
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