PoolCleaner is a static singleton. The pool cleaner thread will not be removed until all JDBC pools have been stopped. So, yes, one application can be the one that starts the thread, but not necessarily the one that stops it
Filip > -----Original Message----- > From: Osipov, Michael [mailto:michael.osi...@siemens.com] > Sent: Wednesday, March 28, 2012 8:29 AM > To: users@tomcat.apache.org > Subject: [JDBC Pool] PoolCleaner creates some sort of memory > > Hi folks, > > Recently this started to pop up in my logs: > 23.03.2012 14:12:28 org.apache.catalina.loader.WebappClassLoader > clearReferencesThreads > SCHWERWIEGEND: The web application [/ket] appears to have started a > thread named [PoolCleaner[18291494:1332172047553]] but has failed to stop > it. This is very likely to create a memory leak. > > There is some similar thread [1] which had no real result. > > I am on Tomcat 6.0.35, all DataSources are created in the context.xml file. > All > DataSources are cleaned up (closed) with a context.xml Listener. The JDBC > Pool is version 7.0.26. > > As far as my debug sessions have revealed (with attached VisualVM), it does > not matter how many apps you deploy the PoolCleanTimer thread is created > only once and retained until all apps have been stopped or removed. This > makes Tomcat think that this is a memory leak. > > Is there a way to associate this thread with another class loader in order to > avoid this problem or create multiple threads or simple ignore this warning > which is not a solution for those who face that issue too? > > Besides that, the numbers in the thread name are not very informative, the > classloader hashcode and timestamp did not really help to to identify > anything. Can this be improved? > > [1] http://www.mail-archive.com/users@tomcat.apache.org/msg87350.html > > With best regards, > Michael Osipov > --------------------------------------------------------------------- > 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
