Apache with Tomcat will be handling JSP's and Servlets;while Orion will act as an application server taking care of EJB's.
Does it sound OK? What are the performance issues for this configuration. I have an existing application running on Apache without any app. server tier. I have to add some functionality to this existing application. This doesn't allow me to use the Orion Web server.
Thanks in advance,
This configuration will likely be slow. My recommendation would be to use Orion for JSP/Servlets/EJB and potentially even for the web server. Orion's web server is probably not as efficient as Apache, but the time saved from communication between Apache and Orion makes it a close call. In either case, Orion can connect to Apache and service all Java tiers. Orion is much faster than Tomcat, see orionserver.com and view the benchmark results.
I agree that you should use Orion to do everything (including being the web server). We have done some limited load testing and Orion performs very nicely.