Siebel Interactive Selling Transact Server Interface Reference > Overview > Architecture >

The Application Server

The Transact Java Engine runs on an application server, and this server manages communications to the Transact database (RDBMS) and the Order Management System. The Transact Java Engine uses Enterprise Java Beans (EJBs) to store, retrieve, and pass configurations from the Siebel application to the Order Management System. EJBs are session and entity beans, distributed objects that encapsulate logic and data within the application server.

Depending on your system configuration, more than one Web server can be positioned between the application server and the Siebel application. If the application server supports clustering, the application server may span more than one machine.

The Transact Java Engine

The Transact Java engine consists of three layers: the Communication, Business Logic, and Data Object layers.

Communication Layer

This layer is a lightweight Java servlet that communicates with Enterprise Java Beans (EJBs). This servlet accepts requests from the browser, directs them to the correct EJB for processing, and then returns the resulting output to the browser or to a targeted Order Management System.

Business Logic Layer

This layer is a set of session EJBs that use the Data Object layer to create, modify, remove, and manipulate data objects. Most processing, including XML creation, occurs on this level because EJBs establish a distributed environment that improves processing. The XML produced on this level is sent to the Order Management System by the Communication layer as HTTP. At this point, the Order Management System controls the request and the subsequent response to the browser.

Data Object Layer

This layer is a set of entity EJBs based on a relational table design. The entity beans include data access and modification methods.

 Siebel Interactive Selling Transact Server Interface Reference 
 Published: 18 April 2003