The web application [xwiki] appears to have started a thread named [non-blocking-thread--p2-t8] but has failed to stop it. This is very likely to create a memory leak

Help / Discuss
1

XWiki 16 + PSQL
Running on Debian
Using Tomcat9
Hello, I’m seeing this on my Tomcat logs, should I worry?

04-Dec-2024 12:15:25.420 WARNING [main] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesThreads The web application [xwiki] appears to have started a thread named [non-blocking-thread--p2-t8] but has failed to stop it. This is very likely to create a memory leak. Stack trace of thread:
 java.base@17.0.13/jdk.internal.misc.Unsafe.park(Native Method)
 java.base@17.0.13/java.util.concurrent.locks.LockSupport.park(LockSupport.java:341)
 java.base@17.0.13/java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionNode.block(AbstractQueuedSynchronizer.java:506)
 java.base@17.0.13/java.util.concurrent.ForkJoinPool.unmanagedBlock(ForkJoinPool.java:3465)
 java.base@17.0.13/java.util.concurrent.ForkJoinPool.managedBlock(ForkJoinPool.java:3436)
 java.base@17.0.13/java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:1630)
 java.base@17.0.13/java.util.concurrent.LinkedBlockingQueue.take(LinkedBlockingQueue.java:435)
 java.base@17.0.13/java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1062)
 java.base@17.0.13/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1122)
 java.base@17.0.13/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)

If so, how do I fix it or mitigate it?

Attached is my logfile.
catalina.2024-12-04.log (245.5 KB)

2

Hello. You should stop tomcat when stopping XWiki and restart Tomcat to restart XWiki (instead of stopping/restarting the XWiki webapp through the Tomcat manager).

We have some issues to fix to prevent tomcat from displaying these messages, see Loading...

3

Hi @vmassol , I am always using systemctl stop tomcat and then I do systemctl start tomcat to start it.

Afterwards I go to the website and load xwiki (XWiki is initializing).

I’ve never used the tomcat manager.

Is that the proper way?

4

Yes, it’s the proper way (it does not prevent Tomcat from complaining about XWiki not cleaning properly, but it’s irrelevant).

1 Like