Hi Konstantin Kolinko, Thanks for the response.
Can you point out some reference where i can know about this permgen memory leak. I am unable to find good article/material on it to understand furthur. Thanks, Pavan. On 10 June 2012 06:59, Konstantin Kolinko <knst.koli...@gmail.com> wrote: > 2012/6/10 Venkata Pavan Kumar Sannisetty <sunny...@gmail.com>: > > I am having this strange issue with the tomcat 5.5 and tomcat 6.0 > servers. > > I have two web applications which will be installed on tomcat.When tomcat > > is started these two web applications also get started simultaneously but > > sometimes one web application fails to initialize because of the init > > failure in one application another application is getting > > classnotfoundexception errors while running. In tomcat 7.0 the > application > > is running fine even if the other application failed to initialize. > > > > After some debugging i came to know there is one jar named crystal.jar > > which is in the web-inf/lib folder of both applications. I have moved the > > jar to common/lib folder of tomcat then it started working fine. I want > to > > know why it is working fine in tomcat 7.0 not in tomcat 5.x and tomcat > 6.x > > versions. Is there any change in classloading architecture between these > > versions ? > > Guessing on a crystal jar^H^H^H ball,.. > > There exist a known kind of PermGen memory leaks, when a library class > is referenced by a system class and thus lives beyond its age. One > example is when Java discovers a JDBC driver, or some other service > and "automatically registers" it. It keeps reference to it in a > system, but the class itself belongs to the web application and has to > be unloaded when application stops - but cannot, because of that > reference. Not all such references are easy to clear. > > One typical symptom in such a case is that the first web application > that relies on this system feature will succeed, but the second and > other ones will fail (because the service that is registered in the > system belongs to first web application and cannot see classes from > classloader of the second application and vice versa). > > Tomcat 7 and recent versions of Tomcat 6 have better protection > against certain known PermGen memory leaks in their default > configuration. > > Tomcat 5.5 does not have such protection at all. > > Best regards, > Konstantin Kolinko > > --------------------------------------------------------------------- > To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org > For additional commands, e-mail: users-h...@tomcat.apache.org > >
