Configure an on demand router (ODR) to dynamically update the Web
server plug-in configuration when the Web server forwards requests to one
or more ODRs. While it is not required that the Web server forward requests
to the ODR, environments exist where this topology is preferable. WebSphere® Extended
Deployment offers this feature so that you do not have to manually update
the plugin-cfg.xml file each time an administrative action
affects this file.
Before you begin
You must decide which ODR will generate a
plugin-cfg.xml file.
This decision depends on how many unique
plugin-cfg.xml files
must be generated. Each ODR can generate a
plugin-cfg.xml file
that causes a Web server plug-in to route to the following elements:
- all ODRs
- all ODRs in the same cell as itself
- all ODRs on the same node as itself
- only to itself
If all Web server plug-ins route to all ODRs, choose any single ODR
to generate a
plugin-cfg.xml file. If, however, you
want a single Web server to front each ODR, configure each ODR to generate
a
plugin-cfg.xml file. The ODR uses the proxy plug-in
configuration policy to determine how to generate a
plugin-cfg.xml file.
About this task
By default, the ODR places the generatedplugin-cfg.xml file
in the WAS_HOME/profiles/profile/etc/ directory. In the
administrative console, you can override the default directory by setting
the ODCPluginXmlDir JVM system property for the ODR to the desired
directory. To set a JVM system property on the ODR, click Servers > On
Demand Routers > odr_name > Java and Process Management > Process Definition
> Java Virtual Machine > Custom Properties > New.
Since the
plugin-cfg.xml file
is generated by the ODR, the
plugin-cfg.xml file is created
on the ODR computer. The ODR that is configured to generate
plugin-cfg.xml files
must be running for the dynamic updates to occur. So, an application must
be started for a corresponding update to the
plugin-cfg.xml file
to occur.
Procedure
- In the administrative console click Servers > On Demand Routers and
select the ODR for the Web server to forward requests to.
- Click an ODR, then On Demand Router Properties > On Demand Router
Settings.
- From the Generate Plugin Configuration list, select the
appropriate option. The right option depends on how many ODRs a
single Web server fronts. For the cell scope, the ODR generates a plug-in
configuration that includes all the URIs that are handled by all the ODRs
in the cell. The node scope includes all the URIs configured for the node.
At the server level, the ODR only generates a plug-in configuration file for
the ODR that is currently configured. This selection causes the plugin-cfg.xml file
to automatically generate each time a change affects the operation of the
plug-in. The plugin-cfg.xml file is on the ODR computer
in the first-defined WAS_HOME/profiles/profile/etc/ directory.
- Restart the ODR to generate the plug-in. The plug-in
is generated each time the ODR changes, for example, if the application starts
or stops, or if a new application is installed.
- If your Web server and ODR are on different machines, set the Plugin
configuration change script path. You must create this script
to copy the generated plugin-cfg.xml file to your remote
Web server. The script runs each time the plugin-cfg.xml file
is updated.
- Depending on the location of the plugin-cfg.xml file
on the Web server, you might also need to modify your Web server configuration
file to point to the correct location of the file and restart your Web server.
If you are using IBM® HTTP Server, modify the httpd.conf file
in the /conf directory of your IBM HTTP Server installation.
Results
The on demand router automatically updates the plugin-cfg.xml file
when changes occur to the configuration.
What to do next
You can also perform this task manually from the administrative console.
In the console, click Servers > Web Servers > Generate Plug-in to configure
the plugin-cfg.xml file.