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Operating Systems: AIX, HP-UX, Linux, Solaris, Windows, z/OS

 

Configure an on demand router to dynamically update the Web server plug-in configuration


You can 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. You might prefer to have the router dynamically update the configuration because you do not need 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 all ODRs, all ODRs in the same cell as itself, all ODRs on the same node as itself, or only to itself. If all Web server plug-ins route to all ODRs, choose any single ODR to generate a plugin-cfg.xml file. However, if you want a single Web server to forward requests to 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

If a single ODR is configured to generate the plugin-cfg.xml file and is stopped, the plugin-cfg.xml will not be regenerated until the ODR is restarted. For this reason, it is recommended that the plugin-cfg.xml generator be run as a highly available service. For a description, see Generating the plug-in configuration in a high availability environment.

By default, the ODR places the generatedplugin-cfg.xml file in the WAS_HOME/profiles/profile_name/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 > on_demand_router > Java and Process Management > Process Definition > Java Virtual Machine > Custom Properties > New. Because 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. Also, an application must be started for a corresponding update to the plugin-cfg.xml file to occur.

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.

 

Procedure

  1. In the administrative console click Servers > On Demand Routers and select the ODR for the Web server to forward requests to.

  2. Click an ODR, then, On Demand Router Properties > On Demand Router Settings.

  3. From the Generate Plugin Configuration list, select the appropriate option. The appropriate option depends on how many ODRs a single Web server forwards requests to. 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 generates a plug-in configuration file only for the ODR that is currently configured. This selection automatically generates the plugin-cfg.xml file 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_name/etc/ directory.

  4. 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.

  5. 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.

  6. Modify your Web server configuration file to point to the correct location of the file and restart your Web server, depending on the location of the plugin-cfg.xml file on the 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 override the default attribute values of the plugin-cfg.xml file that is automatically generated by the on demand router (ODR). See Controlling the generation of the plugin-cfg.xml file for more information.


Subtopics

Controlling the generation of the plugin-cfg.xml file

Generating the plug-in configuration in a high availability environment

 

Related concepts


Overview of request flow prioritization

 

Related tasks


Creating ODRs Creating and configuring ODRs