This is a normal stack trace. It is a zookeeper client thread waiting for watch notifications and such.
-Martin On 10/23/2015 09:04 PM, John Lindwall 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) >
