3.1.1 Purpose and configuration of the system

The systems built using Application Server can be classified into the following two types, depending on the requirements and features of the intended business and the J2EE application that will run on the system:

A Web front-end system is a system (in the case of web-based system) that receives requests sent from a Web browser that acts as the front-end and processes such requests. In this system, servlets, JSPs, and Enterprise Beans run in a J2EE server that runs on the Application Server system.

A Back-end system runs behind the Web front-end system and executes business services that are common to multiple business systems. The following components, applications, or systems send requests to the back-end system:

The Application Server system consists of one or more Web front-end systems and back-end systems, depending on the purpose and scale.

The following figure shows an example of the configuration of a Web front-end system and back-end system:

Figure 3-1 Example configuration of a Web front-end system and a back-end system

[Figure]

When determining the system configuration of the Application Server system, first, determine the basic configuration. This includes determining the combination of systems required to form the entire system. Next, identify the purpose of each constituent system and the points that will be accessed from the client. Further, determine how the software and the processes should be deployed in order to fulfill the common requirements of reliability, performance and extensibility that are expected of any Application Server, as well as the system specific requirements such as connectivity with EIS and load balancing, and thus, design the optimum system configuration.