Web server configuration
Plug-in configuration involves configuring the web server to use the binary plug-in module that WebSphere® Application Server provides. Plug-in configuration also includes updating the plug-in XML configuration file to reflect the current application server configuration. The binary module uses the XML file to help route web client requests.
See the following descriptions of each file.
Web server configuration file
The web server configuration file is installed as part of the web server.
The Web Server Plug-ins Configuration Tool must re-configure the configuration file for a supported web server.
Binary web server plug-in file
An example of a binary plug-in module is the mod_was_ap22_http.dll file for IBM HTTP Server on the Windows platform.
Another example of a binary plug-in module is the QSVTAP20 service program on the IBM i platform.
The binary plug-in file does not change. However, the configuration file for the binary plug-in is an XML file. The application server changes the configuration file when certain changes to your WebSphere Application Server configuration occur.
The binary module reads the XML file to adjust settings and to route requests to the application server.
Plug-in configuration file, plugin-cfg.xml
The plug-in configuration file is an XML file with settings that you can tune in the administrative console. The file lists all of the applications installed on the web server definition. The binary module reads the XML file to adjust settings and to route requests to the application server.
The standalone application server regenerates the plugin-cfg.xml file in the profile_root/config/cells/cell_name/nodes/web_server_name_node/servers/web_server_name directory. Regeneration occurs whenever a change occurs in the application server configuration that affects deployed applications.
When you make application server configuration changes that affect deployed applications, regenerate the plug-in configuration XML file.
After regeneration, propagate (copy) the file to the web server machine. The binary plug-in then has access to the most current copy of its configuration file.
The web server plug-in configuration service automatically regenerates the plugin-cfg.xml file after certain events that change the configuration. The configuration service automatically propagates the plugin-cfg.xml file to an IBM HTTP Server machine when the file is regenerated. You must manually copy the file on other web servers.
On IBM i systems, the plug-in is not automatically generated. You must regenerate and propagate the file manually.
Default plug-in configuration file, plugin-cfg.xml
The Web Server Plug-ins Configuration Tool creates the temporary plugin-cfg.xml file in the plugins_root/config/web_server_name directory. The tool creates the file for every remote installation scenario.
The default file is a placeholder that you must replace with the plugin-cfg.xml file from the web server definition on the application server. The default file is a replica of the file that the application server creates for a default standalone application server.
Run the configureweb_server_name script from the app_server_root/bin directory of the application server machine for a remote installation or directly from the plugins_root/bin directory for a local installation. The script creates the web server definition in the configuration files of the default profile. To configure a different profile than the default, edit the configureweb_server_name script. Use the -profileName parameter to identify a profile other than the default profile.
After the web server definition is created, the web server plug-in configuration service within the application server creates the first plugin-cfg.xml file in the web server definition on the application server machine. If you install an application, create a virtual host, or do anything that changes the configuration, you must propagate the updated plugin-cfg.xml file from the application server machine to the web server machine to replace the default file.
Configureweb_server_name script for the web server definition
The Web Server Plug-ins Configuration Tool creates the configureweb_server_name script on the web server machine in the plugins_root/bin directory. If one machine in a remote scenario is running under an operating system like AIX® or Linux® and the other machine is running under Windows, use the script created in the plugins_root/bin/crossPlatformScripts directory. The script is created for remote installation scenarios only.
Copy the script from the web server machine to the app_server_root/bin directory on a remote application server machine. You do not have to copy the script on a local installation. Run the script to create a web server definition in the configuration of the application server.
The problem is a potential conflict between a shell environment variable, the WAS_USER_SCRIPT environment variable, and the actual default profile. The script always works against the default profile. If the WAS_USER_SCRIPT environment variable is set, however, a conflict arises as the script attempts to work on the profile identified by the variable.
The variable is easy to set accidentally. Issue any command from the profile_root/bin directory of any profile and the variable is set to that profile.
If you have more than one profile on your system, the potential exists that the default profile and the profile identified by the variable are different profiles. If so, a conflict occurs and the script might not create the web server definition in the correct profile, or might not create the web server definition at all.
If a web server definition already exists for a standalone application server, running the script does not add a new web server definition. Each standalone application server can have only one web server definition.
Configuration script for the Web server definition
Configuring your web server with the configureOs400WebserverDefinition script or using the IBM i Administrative GUI creates the configureweb_server_name script on the web server machine in the plugins_root/bin directory. The script is created for remote installation scenarios only.
Copy the script from the web server machine to the app_server_root/bin directory in the IBM i partition. Run the script to create a web server definition in the configuration of the application server.
If a web server definition already exists for a standalone application server, running the script does not add a new web server definition. Each standalone application server can have only one Web server definition.
Alternatively, you can use the configureOs400WebServerDefinition
and
removeOs400WebServerDefinition
scripts to perform these tasks.
Replacing the default plug-in configuration file with the file from the web server definition (propagation)
The default file uses fixed parameter values that might not match the parameter values in the actual file on the application server. The default file is a placeholder only.
The file cannot reflect changes that occur in the application server configuration. The file also cannot reflect nondefault values that might be in effect on the application server.
The application server must have the following values in the actual plugin-cfg.xml file. If so, the default file can successfully configure the binary plug-in module. Then, the plug-in module can successfully communicate with the web server and the application server.
Suppose that the application server does not have the following values in the actual plugin-cfg.xml file. In that case, the default file configures the binary plug-in module incorrectly. The plug-in module can always communicate with the web server. But with an improper configuration file, the plug-in module cannot communicate successfully with the application server.