IBM WAS Architecture

IBM WebSphere Application Server - Express architecture

The combination of the following software components makes the architecture of IBM WebSphere Application Server (WAS)

• WebSphere subsystem
• Application server
• Web container
• Name server
• Security server
• HTTP server
• WebSphere plug-in 

WebSphere subsystem

The IBM WebSphere Application Server – WebSphere subsystem, QASE5, has the jobs that pertain to IBM WebSphere Application Server. In addition to the jobs running in the QASE5 subsystem, applications of yours may also use the jobs that are running in any other subsystems.

Application server

The Application server provides the runtime environment for server-side Java components (such as servlets and Java Server Pages). An application server contains the following architectural components:

Web container

The Web container runs within the application server and handles requests for servlets, Java Server Pages files, and the Web applications that contain them.

Name server

The Java Naming and Directory Interface, or JNDI, is used to provide access to Java components within a distributed computing environment. The WebSphere Application Server - Express name server provides the implementation of the JNDI service. You can bind WebSphere Application Server - Express resources to JNDI names, which allows applications to access resources such as data sources and mail providers. 

Security server

The WebSphere Application Server - Express security server provides security infrastructure and mechanisms to protect sensitive application resources and administrative resources and to address enterprise end-to-end security requirements on authentication, on resource access control, on data integrity, confidentiality, and privacy, and on secure interoperability.

HTTP server

The HTTP server receives requests for server-side components (such as servlets and Java Server Pages) and passes the requests to WebSphere Application Server - Express through an interface called the WebSphere plug-in. WebSphere Application Server - Express supports these HTTP servers:

• IBM HTTP Server for iSeries (powered by Apache)
• Lotus Domino HTTP Server

 WebSphere plug-in

WebSphere Web server plug-ins enables the Web server to communicate requests for dynamic content, such as servlets, to the application server. WebSphere Application Server - Express ships two plug-ins; one for IBM HTTP Server for iSeries (powered by Apache) and one for Lotus Domino HTTP Server. The plug-ins use a configuration files to determine whether a request should be handled by the Web server or the application server. For example, the plug-in forwards servlets requests to the application server. If you are using the HTTP server to serve HTML files, then the plug-in forwards HTML requests to the HTTP server.