Setting up Version 4.0.x and Version 5.x coexistence

Before you begin

You must migrate prerequisite and corequisite programs to the levels required by WebSphere Application Server, Version 5.x. You must also identify ports in use in Version 4.0.x before you begin the Version 5.x installation, to avoid possible conflicts during coexistence. The first two steps in this task describe these activities.

Why and when to perform this task

You can install WebSphere Application Server Version 4.0.x and Version 5 on the same node. When the Version 5 installation wizard detects the Version 4.0.x installation, it displays the migration and coexistence panel, where you can select either option, both options, or neither option. If you select coexistence, the installation wizard displays the coexistence panel to ensure you install Version 5 without port conflicts.

Silent installation also supports configuring for coexistence silently. You can specify non-conflicting port assignments in the options response file, as described in Installing silently.

By default, there are port conflicts between Version 4.0.x and Version 5 that you must resolve. Also, if you migrate more than two Version 4.0.x nodes to Version 5, there are port conflicts that you must resolve, as described in the Setting up Version 5 coexistence topic.

Steps for this task

  1. Migrate prerequisite and corequisite programs to the levels required by WebSphere Application Server, Version 5.

    Refer to the Look it up! (References and specifications)   WebSphere Application Server detailed system requirements
    http://www.ibm.com/support/docview.wss?rs=180&uid=swg27006921 site for current requirements.

  2. Resolve port conflicts.

    Refer to the Port number settings in WebSphere Application Server versions topic to see a list of default port numbers, and where they are defined.

    Inspect the configuration of the previous version:

    • For WebSphere Application Server Advanced Single Server Edition, Version 4.0.x: Inspect the server-cfg.xml file to get port values for the configuration.
    • For WebSphere Application Server Advanced Edition, Version 4.0.x: Inspect the admin.config file to get port values for the configuration. When the administrative server is running, use this command:
      xmlConfig -export config.xml -nodeName theNodeName
      

      Review the config.xml file to look for <node action="update" name="nodename"> to find the appropriate node and port number assignments in the file. The installation wizard displays a default set of coexistence port numbers as suggested Version 5 port numbers. Change the values to ports that are not in use. The installation wizard uses whatever values you approve.

      Change conflicting HTTP transport ports manually, if necessary.

  3. Associate a Web server with each WebSphere Application Server.
    • Use a separate Web server for each WebSphere Application Server.
      1. Create a Web server instance using the Web server documentation.
      2. Select the appropriate Web Server plug-in feature during WebSphere Application Server installation, and identify the Web server configuration file location. (For example, identify the location of the httpd.conf file for IBM HTTP Server.)
    • Use the same Web server for both WebSphere Application Server versions.

      To use the same Web server for both Application Server versions, you must first upgrade the Web server to the common level supported by both versions of the application server.

      Follow this procedure to use the same Web server for both WebSphere Application Server versions.

    1. Select the appropriate Web Server plug-in feature during WebSphere Application Server installation, and identify the Web server configuration file location. (For example, identify the location of the httpd.conf file for the IBM HTTP Server that is associated with Version 4.0.x.)
    2. Edit the Web server configuration file to remove entries for Version 4.0.x, as described in the Migrating plug-ins, one machine at a time (tins_websmig2) topic in the base Application Server information center.

      The WebSphere Application Server, Version 5 plug-in acts as the routing agent to route requests to both versions.

    3. Generate the plug-in configuration files for both versions of the Application Server.
    4. Edit the Version 4.0.x plugin-cfg.xml file and the Version 5 plugin-cfg.xml file, to merge their entries into a combined file of all Web context roots.

      Web context roots must be unique across Application Server versions. If there is a common context root across versions, requests are served by the plug-in instance that was last loaded.

      If you have both Version 4.0.x Samples and Version 5 Samples in the file, you can access only the Version 5 Samples after merging the configuration files because there is one context root for Samples.

      Whenever you modify the plugin-cfg.xml file for either version, you must manually merge the files again, to make a master file.

      This is described in the Preparing to install and configure a Web server (tins_webserver) topic in the base Application Server information center.

      Whenever you modify the plugin-cfg.xml file for either version, you must manually merge the files again, to make a master file.

    5. Replace the original plugin-cfg.xml file of the Version 5 installation with the master file.
  4. Fix any problems with environmental variables on Windows platforms.
    For example, installing WebSphere Application Server, Version 5 updates the system variable PATH, potentially affecting tools with the same name across installations. To run tools with conflicting names, alter the PATH environment variable in a command window and place the directory for the former installation before the directory for the latter installation. For example, PATH=E:\WebSphere\AppServer\40\bin;%PATH%. Then, invoke the tools from the bin directory.

What to do next

Return to Migrating and coexisting to continue.

Related tasks
Setting up Version 5 coexistence
Related reference
Port number settings in WebSphere Application Server versions
Installation: Resources for learning



Searchable topic ID:   tins_coexist2
Last updated: Jun 21, 2007 8:07:48 PM CDT    WebSphere Business Integration Server Foundation, Version 5.0.2
http://publib.boulder.ibm.com/infocenter/wasinfo/index.jsp?topic=/com.ibm.wasee.doc/info/ee/ae/tins_coexist2.html

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