Set up Version 5 coexistence

This task describes how to install a Version 5.1 product to coexist with another installation instance of Version 5.1 or V5.x. After installing the WAS product, you can install it again on the same machine. Select the new installation option from the installation wizard panel, to install a new instance instead of adding features to the last installation, and to install into a separate installation directory. Select the coexistence option to provide nonconflicting ports.

Each installation of the base product is a stand-alone Application Server (server) with its own set of unique configuration files.

Be aware of multiple instance limitations:

• If you attempt to install V5.0.2 or V5.1 when V5.0.0 or V5.0.1 with the embedded messaging feature is already on the machine, you cannot select the embedded messaging feature. An incompatibility exists between the service level versions of embedded messaging. The level of embedded messaging for V5.0.0 and V5.0.1 differs from the level supported on V5.0.2 and V5.1. Upgrade the V5.0.0 or V5.0.1 node to V5.0.2 before installing another instance of V5.0.2 or V5.1.

• If you install more than one instance, the most recent installation is the only one in the operating system registry.

• If you install more than two instances, the third and subsequent installations require that you change all port numbers on the coexistence panel, to avoid potential conflicts.

• To uninstall a registered product instance, always use the operating system remove program function, such as the Add/Remove Program utility on Windows platforms. To uninstall an unregistered instance, use the Uninstall.exe or uninstall command in the $WAS_HOME/_uninstall directory that matches the instance you intend to remove.

Reasons to use multiple installation instances include...

• You can achieve complete isolation between each WebSphere Application Server instance. You can uninstall one instance independently of the others.

• You can install the base WAS more than once on the same machine.

• You can install the base V5.0.x and V5.1 WAS on the same machine although consider the limitation regarding the embedded messaging feature.

Reasons to not use multiple installation instances include...

• The machine might have a hard disk space constraint.

• Use the operating system registry to locate the last installed instance of a WAS product only.

  When you install any product a second time, the last installation is the one that appears in the registry.

• Uninstalling the last instance removes any record of the product in the registry.

  Suppose you have installed three instances of the base WebSphere Application Server product. You use the remove program function of the operating system to uninstall the registered third copy of the base product. A registry record no longer exists that indicates the existence of the other two installation instances. Other applications cannot use a query of the operating system registry to detect the presence of either base WAS product instance.

The Creating multiple Version 5 configuration instances topic describes installing the base WAS product once and creating multiple configuration instances.

Use the following procedure to install multiple installation instances.

1. Upgrade V5.0.0 or V5.0.1 with embedded messaging to V5.0.2.

2. Use the installation wizard to install another installation.If you intend to share a single Web server among installations, install a Web server plug-in feature during one installation only, as described in the next step.

3. Share a Web server among multiple installation instances.

   1. Select a Web server plug-in feature during one installation only.

   2. Generate the plug-in configuration files for every installation instance.

   3. Edit the plugin-cfg.xml configuration files to merge them into one master configuration.

   4. Replace the original plugin-cfg.xml file with the master file on the Application Server where you selected the Web server plug-in feature.

   You can access samples from only one of the installation instances.

4. Create additional servers in a multiple instance or coexistence environment.

5. Change port assignments in configuration files if you have a node that you cannot start because of port conflicts.

 

See Also

Creating servers in coexistence or multiple instance environments
Changing HTTP transport ports
Creating multiple Version 5 configuration instances
Port number settings in WAS versions

 

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