A Comparative Evaluation of EJB Implementation Methods

As e-businesses are becoming ubiquitous, enhancing the performance and scalability of e-business systems has become an increasingly important topic of investigation. As Vitruvius (70-25 BC) put it succinctly 'function follows form', the ability of a system to perform well and scale easily is influenced by how the system itself is formed or implemented. A common approach to implement e-business systems is to make use of off-the-shelf enterprise middleware systems, such as a J2EE-compliant application server. Such middleware systems handle several, often complex, issues and thus simplify application development. They however allow developers the freedom not to use particular forms of support they offer and build their own mechanisms instead. This flexibility gives rise to many implementation methods. The work reported here evaluates these methods for Response Time and Throughput under various environments related to both client side (external to the system) and application execution (internal). To this end, one of the most widespread technologies used by the industry, the Enterprise Java Beans (EJB), is chosen; we have considered six commonly used implementation methods for an e-auction application and five different client-side and execution environments. The resulting study, which involves 78 experimental runs, identifies the strengths and the weaknesses of each implementation method under 13 different scenarios. It thus offers reliable guidelines for developers and valuable insights to researchers.