about EJB performance Where can I find articles about EJB performance?
An official white paper about EJB performance: http://developer.java.sun.com/developer/technicalArticles/ebeans/ejbperformance/
http://www.jdance.com/ejbperformance.shtm has some links to pages about EJB performance
If you use IBM WebSphere, http://advisor.com/wFiles.nsf/wCatID/Miw0009.vonag01.zip/$file/Vonag01.zip can be useful.
But if you use WebLogic 5.1, in http://www.weblogic.com/docs51/classdocs/API_ejb/EJB_deploy.html#1032825 you can see some tips.
Here, you can see how to reduce network traffic