[LOG4J2-3026] WatchManager does not stop its ConfigurationScheduler thereby leaking a thread

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Not A Problem
• Affects Version/s: 2.14.0
• Fix Version/s: 3.0.0, 2.14.1
• Component/s: Core
• Assignee: Gary D. Gregory
• Reporter: Gary D. Gregory
• Created: 24/Feb/21 19:51
• Updated: 26/Feb/21 15:42
• Resolved: 26/Feb/21 13:58

Description

The WatchManager does not stop its ConfigurationScheduler thereby leaking a thread as reported by Tomcat 9:

24-Feb-2021 14:13:49.747 WARNING [http-nio-8080-exec-9] org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesThreads The web application [discoveryrecorder] appears to have started a thread named [Log4j2-TF-8-Scheduled-2] but has failed to stop it. This is very likely to create a memory leak. Stack trace of thread:
 sun.misc.Unsafe.park(Native Method)
 java.util.concurrent.locks.LockSupport.parkNanos(LockSupport.java:215)
 java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitNanos(AbstractQueuedSynchronizer.java:2078)
 java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(ScheduledThreadPoolExecutor.java:1093)
 java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(ScheduledThreadPoolExecutor.java:809)
 java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1074)
 java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1134)
 java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
 java.lang.Thread.run(Thread.java:748)

I am experiencing this in 2.14.0 but it looks to have been a bug since day 1.
Windows 10, Java 8.