- Performance: Web Servers are much better tunned to server static content than the Application server. Also you can install web server on different machine and reduce the load on the application server as it only has to serve dynamic content
- Load balancing: In case of clustered environment you can use web server for distributing requests among different clusters.
- Security: You can configure web server so that the incoming request ends at web server and your application server allows only secured connection from Web server.
- Session affinity
The IBM WebSphere APplication server supports following web servers
- Apache HTTP Server
- Domino Web Server
- IBM HTTP Server
- Microsoft Internet Information Services
- Sun Java System Web Server (formerly Sun ONE and iPlanet™)
The way it works is first you install web server and copy your static content such as .js, .css files, images on the web server. Then you install a plug-in on web server. Plug-in takes a look at the incoming request and depending on the URL it decides if this is the request for static content or dynamic content, if it is request for dynamic content it forwards control to WAS.A web server plug-in is specific to the type of web server. It is installed on the web server machine and configured in the web server configuration.
A plug-in configuration file is generated on the application server and placed on the Web Server is used for routing information. In order to manage the generationo and propagation of these plug-in configuration files, web servers are defined to the WebSphere Application Server configuration repository. In some cases web server is also managed by the WAS admin tools
application server can have only one Web server definition. A distributed server
environment, on the other hand, can have multiple Web server definitions. The
script creates a new Web server definition unless the Web server name is the
The Plug-ins installation wizard stores the script in the
directory on the Web server machine. If the plug-in is installed locally (on the
same machine as the application server), the configuration script will be run
For remote installations, you must copy the script from the Web server machine
execution. The script runs against the default profile. If one machine is running
under Linux or UNIX and the other machine is running under Windows, use the
script created in the