ThreadDumps on AEM 6.3 instances

[maryw24753203]

Hi All ,

we are seeing thread dumps on our AEM instances . when we analyze the dump we found most of the threads are in waiting state (80%).

below are the details on our instance

1. Java Version - OpenJDK version "1.8.0_10"
2. AEM Directory is owned by root , and we dont have any service account for AEM to run under . do we need to setup one?
3. Java Opts - -Xms4096m -Xmx4096m -XX:MetaspaceSize=100m
4. we have online revision clean up which runs as suggested .  do we have to run any other maintenance tasks or scheduled system restarts ?

please provide us with steps to follow to avoid these thread dumps

below is info from thread Dump

86 threads in WAITING state

sling-oak-113 - priority:5 - threadId:0x18b3 - nativeId:0xffffffff - state:WAITING
stackTrace:
java.lang.Thread.State: WAITING (on object monitor)
at sun.misc.Unsafe.park(Native Method)
- waiting to lock <0x5dc62067> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject) owned by "null" tid=0x-1
at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039)
at java.util.concurrent.LinkedBlockingQueue.take(LinkedBlockingQueue.java:442)
at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1067)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1127)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)

[smacdonald2008]

I am checkign internally for this one. There may be a good doc on this. In mean time - look here: CQ Thread Dump - CQ Tutorials

[maryw24753203]

Thank you it will be very helpfull if we get the doc. we will also refer to the link provided.

Mean while can you please help us in understanding the below issues

1. ifsopenjdk 8 supported by AEM 6.3  , as openjdk is reference implementation of SE JDK 8? or do we need to install Oracle SE 8 JDK on all the AEM 6.3 instances.
2. AEM Directory is owned by root , and we dont have any service account for AEM to run under . do we need to setup one?
3. Java Opts - -Xms4096m -Xmx4096m -XX:MetaspaceSize=100m
4. we have online revision clean up which runs as suggested .  do we have to run any other maintenance tasks or scheduled system restarts ?

[kautuk_sahni]

Platform supported can be been seen at Technical Requirements

I don't see open SDK support as per the documentation.

~kautuk

[chetanm_oct]

Thread from ThreadExeutorPool in waiting state is normal as reported in post is normal and not cause of concern

[bartek__w]

Hello @maryw24753203 

any updates here ?