In our paper Performance and Scalability of EJB applications, we investigate the combined effect of application implementation method, container design, and efficiency of communication layers on the performance scalability of J2EE application servers by measurement of the auction site server RUBiS.

We use five versions of the auction site. The first version uses stateless session beans, making only minimal use of the services provided by the Enterprise JavaBeans (EJB) container. Two versions uses entity beans, one with container-managed persistence and the other with bean-managed persistence. The fourth version applies the session façade pattern, using session beans as a façade to access entity beans. The last version uses EJB 2.0 local interfaces with the session façade pattern. We evaluate these different implementations on two popular open-source EJB containers with orthogonal designs. JBoss uses dynamic proxies to generate the container classes at run time, making an extensive use of reflection. JOnAS pre-compiles classes during deployment, minimizing the use of reflection at run time. We also evaluate the communication optimizations provided by each of these EJB containers.

We present the experimental results for each implementation. For each implementation, we evaluate up to 5 different configurations referred to as follows:

• Java Servlets: the Java Servlets implementation,
• JBoss: the JBoss container using JNP and passing objects by value,
• JOnAS-RMI: the JOnAS container using RMI,
• JBoss optimized calls: the JBoss container using JNP and passing objects by reference,
• JOnAS-Jeremie: the JOnAS container using the Jeremie communication layer.