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Posted to user@zookeeper.apache.org by John Lindwall <jl...@yahoo.com.INVALID> on 2015/10/24 03:04:21 UTC
Thread dump looks OK?
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$EventThread.run(ClientCnxn.java:494)
Re: Thread dump looks OK?
Posted by Rakesh Radhakrishnan <ra...@gmail.com>.
Hi John,
In your threaddump, EventTread is waiting to get a watch notification or
operation response from the ZooKeeper server. Event thread uses the
datastructure (EventThread#waitingEvents) to keep all the notifications
from the ZooKeeper server and will wait until an item is available. So, I
think there is no issue with this threaddump.
Are you facing any issue in your cluster?
Regards,
Rakesh
On Sat, Oct 24, 2015 at 6:34 AM, John Lindwall <jl...@yahoo.com.invalid>
wrote:
> We use zookeeper 3.4.6
>
> Our webapp running in a tomcat server suffered a condition where user
> sessions seemed to "freeze". We got a single thread dump at that time. I am
> curious about a particular stacktrace that is seen in the thread dump,
> related to zookeeper.
>
> Does the following stacktrace cause any alarm or concern? Thanks!
>
> "ajp-bio-8012-exec-561-EventThread" daemon prio=3 tid=0x0000000105a46000
> nid=0x11fa waiting on condition [0xfffffffd967ff000]
>
> java.lang.Thread.State: WAITING (parking)
>
> at sun.misc.Unsafe.park(Native Method)
>
> - parking to wait for <0xffffffff11fd9110> (a
> java.util.concurrent.locks.AbstractQueuedSynchronizer$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)
>
Re: Thread dump looks OK?
Posted by Martin Serrano <ma...@attivio.com>.
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)
>