> From: Narayanaswamy, Mohan > [mailto:[EMAIL PROTECTED] > Subject: RE: Tomcat PermGen OutOfMemoryException solution? > > Do you mean that tomcat(or Java) will have multiple copies > of the same class, assuming same jar shipped with different > applications, Can't tomcat class loader identify & avoid them?
No, there's no guarantee they're identical, even when they have the same name. There isn't one Tomcat class loader, there are several, including one per deployed webapp. When a webapp is undeployed, the associated classloader and therefore the webapp classes should be reclaimable by garbage collection. Unfortunately, things like badly implemented shared libraries often prevent that from happening. > If there is a web hosting company, multiple application > may use the same jar (say struts1.x.jar) - so does JVM > keep multiple copies of the class in PermGen? Yes, all classes are qualified by the classloader that brought them into the JVM. There cannot be duplicates within a given classloader's space, but each classloader theoretically could have its own copy of a given class. Read the Tomcat doc for more details: http://tomcat.apache.org/tomcat-5.5-doc/class-loader-howto.html - Chuck THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY MATERIAL and is thus for use only by the intended recipient. If you received this in error, please contact the sender and delete the e-mail and its attachments from all computers. --------------------------------------------------------------------- To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
