You can install a Version 6.0.x product to coexist with another
installation instance of Version 5.x.
Before you begin
After installing the WebSphere Application Server product, you can
install it again on the same machine.
About this task
Each installation of the base product is a standalone application
server (server1) with its own set of unique configuration files.
Be
aware of multiple instance limitations:
- 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 command
in the app_server_root/_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 WebSphere Application Server more than once on
the same machine.
- You can install the base Version 5.x and
Version 6.0.x WebSphere Application Server on the same machine.
Reasons to not use multiple installation instances include:
- The machine might have a hard-disk space constraint.
- You can use the operating system registry to locate the last installed
instance of a WebSphere Application Server product only.
When you install
any product a second time, the last installation is the one that is displayed
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 WebSphere Application Server product
instance.
Use the following procedure to install multiple installation instances.
Procedure
- Use the Installation wizard to install another installation.
If you intend to share a single Web server among installations, install
the appropriate Version 6.0.x Web server plug-in using the standalone Web
server plug-in installation wizard that is provided on a separate CD from
the WebSphere Application Server Installation CD.
- Share a Web server among multiple installation instances.
- Use the Plug-in Installation wizard to select a Web server plug-in.
- Use the administrative console to generate the plug-in configuration
files for every installation instance and to then merge them into one master
configuration.
- Use the administrative console to replace the original plugin-cfg.xml file
with the master file on the Web server.
You can access samples from only one of the installation instances.
- Change
port assignments in configuration files if you have a node that you
cannot start because of port conflicts.