The product 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 an application server. The Web server plug-in uses the
XML configuration file to determine whether a request is for an application
server.
Before you begin
- Review the content of the topic "Choosing a front end for your WebSphere® Application Server topology". This
topic helps you determine whether you should set up a Web server plug-in,
a proxy server, or a secure proxy server to provide session affinity,
failover support, and workload balancing for your WebSphere Application Server topology.
- Install your Web server if it is not already installed.
- Verify that your Web server is configured to perform the operations
that are required by Web applications, such as GET and POST. Typically,
configuring your Web server to perform these operations involves setting
a directive in the Web server configuration file. Refer to the Web
server documentation for instructions.
If an operation is not enabled when a servlet or JSP
file requiring the operation is accessed, an error message displays,
such as this one from the IBM
® HTTP
Server:
IMW0093E Method POST is disabled on this server.
- Make sure the appropriate plug-in file has
been installed on your Web server and the configureWeb_server_name
script has been run to create and configure the Web server definition
for this Web server.
If you are using the z/OS® IBM HTTP
Server powered by Apache, that is provided with the product, see the
information about installing and configuring the plug-in for IBM HTTP Server for WebSphere Application Server on z/OS.
If you are using
the Version 5.3 HTTP Server that is provided with the z/OS base operating system, see the information
about installing and configuring the plug-in for V5.3 HTTP Server
for z/OS.
If
you are using a distributed platform Web server with a version of
the product that is running on z/OS,
FTP the plug-in to the Web server and use the Plug-in Installation
wizard to install the appropriate plug-in file to your Web server.
About this task
The following steps are performed during the plug-in
installation process. See the Plug-in Installation Roadmap for additional
information.
- A Web server definition is created.
You can also use either
the administrative console or use the ConfigureWebServerDefintion.jacl
script to create a Web server definition. If you use the administrative
console:
- Select the node that was created in the preceding step, and in
the Server name field, enter the local name of the Web server for
which you are creating a Web server definition.
- Use the wizard to complete the Web server definition.
- An application or modules are mapped to a Web server. If an application
that you want to use with this Web server is already installed, the
application is automatically mapped to the Web server. If the application
is not installed, select this Web server during the Map modules to
servers step of the application installation process.
- The master repository is updated and saved.
When you install a plug-in, the configuration
file for that plug-in is automatically created. You can change or
fine tune the default settings for the properties in this configuration
file. If change any of the settings, you must regenerate the file
before your changes take affect.
Generating
or regenerating the configuration file might take a while to complete.
After it finishes, all objects in the administrative cell use their
newest settings, which the Web server can access. If the Application
Server is on the same physical machine as the Web server, the regeneration
usually takes about 30 to 60 seconds to complete. The regeneration
takes longer if they are not both on the same machine.
The following
procedure describes the steps for updating the plug-in configuration
file, including configuring for SSL and Web server tuning
Procedure
- Use the administrative console to change the settings in
the plug-in configuration file.
When setting up your
Web server plug-in, you must 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.
Avoid trouble: You must delete the
plugin-cfg.xml file
in the
profile_root/config/cells directory
before you complete this task. Otherwise, configuration changes do
not persist to the
plugin-cfg.xml file.
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To
use the administrative console:
- Select web_server_name.
- 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
See the topic about Web server plug-in configuration properties
for information about how to map each property to one of these topics.
Avoid trouble: 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.
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- Click OK.
- You might have to stop the application server and then
start the application server again to enable the Web server to locate
the plugin-cfg.xml file.
- Propagate the plug-in configuration.
The plug-in configuration file (plugin-cfg.xml) is automatically
propagated to the Web server if the Web server plug-in configuration
service is enabled, and one of the following is true:
- The Web server is a local Web server, which means that the Web
server is located on the same machine as an application server.
- The Web server is a remote IBM HTTP
Server Version 7.0 that has
a running IBM HTTP Server administration
server.
If neither of these conditions is true, the plugin-cfg.xml
file must be manually copied to the remote Web server's installation
location. Copy plugin-cfg.xml in <WASROOT>/profiles/<profilename>/config/cells/../../nodes/../servers/<webservername> to
the Web server host location, which is <PluginInstallRoot>/config/<webservername>/.
Important: If you use the FTP function to perform the copy,
and the configuration reload fails, check the file permissions on
the plugin-cfg.xml file and make sure they are set to rw-r--r--. If
the file permissions are not correct, the Web server is not able to
access the new version of the file, which causes the configuration
reload to fail.
If the file permissions are incorrect, issue the
following command to change the file permissions to the appropriate
settings:
chmod 644 plugin-cfg.xml
The remote Web server
installation location is the location you specified when you created
the node for this Web server.
Results
The configuration is complete. To activate the configuration,
stop and restart the Web server. If you encounter problems restarting
your Web server, check the http_plugin.log file for information on
what portion of the plugin-cfg.xml file contains an error. The log
file states the line number on which the error occurred along with
other details that might help you diagnose why the Web server did
not start. You can then use the administrative console to update the
plugin-cfg.xml file.
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 server_name , and then unselect the option.
Avoid trouble: 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.
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