On 31/01/2016 08:06, Yuval Schwartz wrote: > 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?
Sorry, don't know. Never used it. I use YourKit, mainly because they kindly donate free licenses to OpenSource developers to use with their OpenSource projects. Mark > 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 >> >> > --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
