Thanks for your reply. It will certainly be helpful to analyse the thread stack trace. Also which thread are you referring to when you say parallelism. Do you mean multiple JVM instances? As far as design of the application is concerned I dont have much details on it but it exercises many of the current J2EE features , EJB, MDB, JMS, Servlets, JSPs , JDBC etc. I wanted to know if there are configuration things (such as for e.g. maxThreads in jbossweb-tomcat5?.sar/server.xml for HTTP connections, JDBC pool size ) related to EJBs, MDBs, JSPs and other entities of a J2EE stack. Thanks again, -Shrinivas View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3989823#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...