WebSphere Application Server V7.0: Concepts ... - IBM Redbooks

Web server plug-ins
A Web server can serve static contents and requests, like HTML pages.
However, when a request requires dynamic content, such as JSP or servlet
processing, it must be forwarded to WebSphere Application Server for handling.
To forward a request, you use a Web server plug-in that is included with the
WebSphere Application Server packages for installation on a Web server. You
transfer (manually or automatically with the deployment manager) an Extensible
Markup Language (XML) configuration file, configured on the WebSphere
Application Server, to the Web server plug-in directory. The plug-in uses the
configuration file to determine whether a request should be handled by the Web
server or an application server. When WebSphere Application Server receives a
request for an application server, it forwards the request to the appropriate Web
container in the application server. The plug-in can use HTTP or HTTPS to
transmit the request (Figure 3-10).
Request A
Request B
Web Server
Plug-in
Plug-in
config
XML
File
Figure 3-10 Web server plug-in concept with WebSphere Application Server
The plug-in is used for routing requests to one of multiple application servers.
About the sysplex distributor: On the z/OS platform you can also use the
sysplex distributor (SD) for the distribution of requests. The SD allows you to
send requests to the server that keeps its predefined response time goals
best, by questioning the Workload Manager (WLM) component. The SD is an
integral part of the System z operating system.
66 WebSphere Application Server V7.0: Concepts, Planning, and Design
Request B
Application
Server
Application
Server
Application
Server
Node
Application
Server
Request A
Node
Cell