Hellow Mark, Thanks for the reply. Follow up questions below.
On Fri, Jan 29, 2016 at 6:22 PM, Mark Thomas <ma...@apache.org> wrote: > On 29/01/2016 14:34, Yuval Schwartz wrote: > > Hello, > > > > tomcat version: 8.0.22 > > java: jdk1.8.0_05 > > server: Amazon Linux AMI > > > > I get the following warning message in my catalina log when I undeploy a > > web application: > > > > *WARNING [ContainerBackgroundProcessor[StandardEngine[Catalina]]] > > org.apache.catalina.loader.WebappClassLoaderBase.clearReferencesThreads > The > > web application [ROOT##002] appears to have started a thread named > > [pool-2-thread-1] but has failed to stop it. This is very likely to > create > > a memory leak. Stack trace of thread* > > > > As you can see, for some reason, I don't get a stack trace of the thread. > > Therefore, I have no idea how to debug this warning. > > > > This particular warning was generated when tomcat detected an unused > > version and undeployed it (I set undeployOldVersions="true"). > > > > Does anyone know how I can debug this warning. How can I know more about > > this thread? > That looks like a thread from Commons Pool (possibly via DBCP). The only > way to be sure you have a leak or not is to use a profiler. See > > http://home.apache.org/~markt/presentations/2010-11-04-Memory-Leaks-60mins.pdf Is VisualVM a good profiler to start with considering my system? I would just like to confirm that this warning is not something serious. I am currently having a little trouble running VisualVM (jstatd) from a remote machine but can struggle with it a little more to try to get it working. Thanks. > > > I used the manager app and clicked "find leaks" but it said that there > were > > none. > > (Can someone also explain why I have to be cautious when using this > feature > > on production environments). > > It triggers a full GC which may (hopefully briefly) pause the entire JVM. > > Mark > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org > For additional commands, e-mail: users-h...@tomcat.apache.org > >
