Hi John, In your threaddump, EventTread is waiting to get a watch notification or operation response from the ZooKeeper server. Event thread uses the datastructure (EventThread#waitingEvents) to keep all the notifications from the ZooKeeper server and will wait until an item is available. So, I think there is no issue with this threaddump.
Are you facing any issue in your cluster? Regards, Rakesh On Sat, Oct 24, 2015 at 6:34 AM, John Lindwall <[email protected]> wrote: > We use zookeeper 3.4.6 > > Our webapp running in a tomcat server suffered a condition where user > sessions seemed to "freeze". We got a single thread dump at that time. I am > curious about a particular stacktrace that is seen in the thread dump, > related to zookeeper. > > Does the following stacktrace cause any alarm or concern? Thanks! > > "ajp-bio-8012-exec-561-EventThread" daemon prio=3 tid=0x0000000105a46000 > nid=0x11fa waiting on condition [0xfffffffd967ff000] > > java.lang.Thread.State: WAITING (parking) > > at sun.misc.Unsafe.park(Native Method) > > - parking to wait for <0xffffffff11fd9110> (a > java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject) > > at > java.util.concurrent.locks.LockSupport.park(LockSupport.java:186) > > at > java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2043) > > at > java.util.concurrent.LinkedBlockingQueue.take(LinkedBlockingQueue.java:442) > > at > org.apache.zookeeper.ClientCnxn$EventThread.run(ClientCnxn.java:494) >
