Communicating with Web servers

The WebSphere Application Server works with a Web server to route requests for dynamic content, such as servlets, from Web applications. The Web servers are necessary for directing traffic from browsers to the applications that run in WebSphere Application Server. The Web server plug-in uses the XML configuration file to determine whether a request is for the WebSphere Application Server.

• Install your Web server if it is not already installed.

  If you want to run the Web server provided with i5/OS, it is already installed on the machine under product 5722DG1. The i5/OS Web server is known as "IBM HTTP Server for i5/OS." The "IBM HTTP Server for WebSphere Application Server" is different than the IBM HTTP Server for i5/OS. "IBM HTTP Server for WebSphere Application Server" is provided with the WebSphere Application Server product and does not run on i5/OS systems.

  If you want to use an IBM HTTP Server for WebSphere Application Server, see Installing IBM HTTP Server. Otherwise, see the installation information provided with your Web server.

• Ensure that your Web server is configured to perform operations required by Web applications, such as GET and POST. Typically, this involves setting a directive in the Web server configuration file (such as the httpd.conf file for an IBM HTTP Server). Refer to the Web server documentation for instructions.

Overview

The appropriate plug-in file is installed. In addition, an http profile is created (/QIBM/UrodData/WebSphere/Plugins/V61/webserver/profiles/http). The http profile can be used to facilitate the creation of Web server definitions. Refer to Selecting a Web server topology diagram and roadmap for instructions on how to configure IBM HTTP Server for i5/OS to communicate with a WebSphere Application Server.

The following procedure describes the steps for updating the plug-in configuration file, including configuring for SSL and Web server tuning

Procedure

1. Use the administrative console to change the settings in the plug-in configuration file. When setting up your Web server plug-in, decide whether or not to have the configuration automatically generated in response to a configuration change. When the Web server plug-in configuration service is enabled and any of the following conditions occur, the plug-in configuration file is automatically generated:

   • When the Web server is created or saved.

   • When an application is installed.

   • When an application is uninstalled.

   • When the virtual host definition is updated

   You can either use the administrative console, or issue the GenPluginCfg command to regenerate your plugin-cfg.xml file. To use the administrative console:

   1. Select Servers > Web Servers > webserver > plug-in properties.

   2. Select Automatically generate plug-in configuration file or click one or more of the following topics to manually configure the plugin-cfg.xml file:

      • Caching

      • Request and response

      • Request routing

      • Custom Properties

      
      Web server plug-in configuration properties maps each property to one of these topics.

      Note: It is recommended that you do not manually update the plugin-cfg.xml file. Any manual updates you make for a given Web server are overridden whenever the plugin-cfg.xml file for that Web server is regenerated.

   3. Click OK.

   4. Propagate the plug-in configuration. To propagate the plug-in configuration from the administrative console, click Servers > Web servers >webserver. Select the webserver name and then click Propagate Plug-in.

      Another method to propagate the plug-in configuration is to run the GenPluginCfg command.

      You do not need to propagate the plug-in configuration if the Web server is on the same machine as the associated stand-alone WebSphere Application Server. If the propagation of the plug-in configuration fails due to an unknown cause, manually copy the plugin-cfg.xml file to the remote Web server's installation location.

      If you use the FTP function to perform the copy, and the configuration reload fails, check the file authorities on the plugin-cfg.xml file and make sure that users QTMHHTTP, QNOTES and QEJBSVR have RWX authority. If the authorities are not correct, the Web server will not be able to access the new version of the file, which causes the configuration reload to fail. To check the authorities, run the following i5/OS command:

      wrklnk 'plug_in_folder_location/plugin-cfg.xml' 

      Then select option 9 to view the authorities that are assigned to the users (QTMHHTTP, QNOTES and QEJBSVR). If the authorities are incorrect, issue the following i5/OS command to change the file authorities to the appropriate settings:

      CHGAUT USER(QEJBSVR QTMHHTTP QNOTES) OBJ('plug_in_folder_location/plugin-cfg.xml') DTAAUT(*RWX)

      The plug_in_folder_location is the location you specified when you FTP'ed the plugin-cfg.xml file.

   5. You might need to stop the application server and then start the application server again to enable the Web server to locate the plugin-cfg.xml file.

2. If you want to enable the Application Server to use the private headers that the Web server plug-in sends, make sure the transport you are using is configured for SSL and is trusted. If a trust file definition is not included, the private headers will be ignored, and the application server might not locate the requested application.

   If you are using an HTTP transport, make sure the transport is configured for SSL and the Trusted custom property for the transport is set to false.

   After you enable the use of private headers, this transport trusts all inbound private headers it receives. Therefore, ensure that all inbound paths to this transport are trusted.

3. Tune your Web server. See Tuning Web servers for more information.

Results

If applications are infrequently installed or uninstalled, which is usually the situation in a production environment, or if you can tolerate the performance impact of generating and distributing the plug-in configuration file each time any of the previously listed actions occur, you should consider enabling this service.

If you are making a series of simultaneous changes, like installing numerous applications, you might want the configuration service disabled until after you make the last change. The Web server plug-in configuration service is enabled by default. To disable this service, in the administrative console click elect Servers > Application Servers > server_name > Administration Services >Web server plug-in configuration service and then unselect the Enable automated Web server configuration processing option.

If your installation uses a firewall, make sure you configure the Web server plug-in to use a port that has been opened. (See your security administrator for information on how to obtain an open port.)

Related concepts

Related tasks