Hello Jenny, > -----Ursprüngliche Nachricht----- > Von: Ying Jin <jiny4...@gmail.com> > Gesendet: Samstag, 1. Juni 2024 00:18 > An: Tomcat Users List <users@tomcat.apache.org> > Betreff: Re: Tomcat 9 memory leak message > > Chris, > > Thanks for your reply! > > We already removed the ojdbc8.jar file from the application's Web-inf/lib > folder as suggested in the following post, however, we still got the warning > messages below after the application is deployed to the Tomcat 9 server. > > https://stackoverflow.com/questions/6981564/why-must-the-jdbc-driver-be- > put-in-tomcat-home-lib-folder > > WARNING: The web application [Our Web Application Name] appears to have > started a thread named [InterruptTimer] but has failed to stop it. This is > very > likely to create a memory leak. Stack trace of thread: > > WARNING: The web application [Our Web Application Name] appears to have > started a thread named [oracle.jdbc.diagnostics.Diagnostic.CLOCK] but has > failed to stop it. This is very likely to create a memory leak. Stack trace of > thread:
I don't know which Oracle Version you are using. The JDBC-Driver seems to start some threads, but they are not stopped at shutdown of the application. One of the issues seems to be resolved in a newer version: https://stackoverflow.com/questions/78300946/how-to-not-run-or-stop-oracle-23-jdbc-driver-diagnostic-clock-thread > > I also read some posts saying these warning messages can be safely ignored if > the Tomcat version is greater than 7.0. I'm not sure if this is correct or > not. > > Please advise, > > Many thanks! > Jenny > > On Fri, May 31, 2024 at 3:50 PM Christopher Schultz < > ch...@christopherschultz.net> wrote: > > > Jenny, > > > > On 5/31/24 14:52, Ying Jin wrote: > > > We removed the ojdbc8 driver jar from web-inf/lib from the web > > > application and kept the ojdbc8 jar file in the Tomcat/lib folder, > > > but we still can see the following memory link warning message > > > whenever we redeploy the web application. We use the Tomcat 9 server > > > in the Linux environment. > > > > This list strips attachments. Can you re-post with text-only? > > > > > The other warning message is about the "validateFile Problem with > > > jar file /tomcat/lib/jolokia.jar. My question is if we can safely > > > ignore these warning messages or not. > > > > > > It would be great if you can shed some light on this issue. > > > > If the message is something like "driver cannot be unloaded" then > > check Tomcat with a debugger or even something like JVisualVM to see > > how many WebappClassLoaders you have in memory. > > > > If the driver causes the web application ClassLoader to be "pinned" in > > memory, then it will never be removed and all those classes will > > continue to use-up heap space until you restart the JVM. This gets > > worse every time you reload your application without restarting the > > JVM. The Manager application web UI can help you diagnose these a little. > > > > The validation problem with the Jolokia JAR file will depend upon > > exactly what it says. I would first get a replacement copy of the > > Jolokia JAR file before bothering to try to diagnose it any further. > > > > -chris > > > > --------------------------------------------------------------------- > > To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org > > For additional commands, e-mail: users-h...@tomcat.apache.org > > > >
