PermGen is for long term storage, ie class file definitions, and I thought (but am not sure) that the memory would be shared between different classloader and hence web applications. Therefore, the AR API Field class is stored once and shared between multiple Mid Tier instances. But maybe I'm wrong - it needs some googling.
Even so, I'd always go for separate JVMs with such a memory hungry application. Unless the ehcache is being shared between the Mid Tier web applications (which I don't think it does by default), then two Mid Tier applications in one Tomcat will consume almost as much memory as two Tomcats running Mid Tier. The overhead of Tomcat's memory requirements are irrelevant in the wider context of running Mid Tier. I've worked with many organisations who also take the view that one JVM runs one web application, even though one can run many applications in a JVM. I find this particularly puzzling for organisations who have shelled out many dollars on Websphere/Weblogic/JBoss. They have attractive consoles for application management, yet the organisation develops a policy of one web application per JVM. I wonder how long we'll need to carry on discussing Mid Tier's poor performance before someone in BMC takes the problem seriously and fixes it :) _______________________________________________________________________________ UNSUBSCRIBE or access ARSlist Archives at www.arslist.org "Where the Answers Are, and have been for 20 years"
