#### To Add Cluster Support to a Domain

If your domain is not configured to support clustering, and you require to use clustering features of Application Server, add cluster support to the domain. For example, a domain that is running a developer profile is not configured to support clustering. Use the Admin Console Application Server node General tab to upgrade the domain to support clustering.

The implications of adding cluster support to a domain are as follows:

- The `domain.xml` file of the domain is modified to support clustering. The modifications include, for example, the addition of system properties and changes to the template configuration. Only the `domain.xml` file is modified. All other files in the domain's directory are left unchanged.

- The server will support both clusters and standalone server instances.

- By default, in-memory replication will be used for applications that are required to be highly available.

- All the applications that are currently deployed on the server will continue to work.

- This change will take effect after the server is restarted and, if CLI multimode is running, after the `asadmin` CLI is restarted.

###### Before You Begin

To enable you to revert the domain to its original configuration if necessary, back up the `domain.xml` file of the domain.

Because the administration server will support clusters after the upgrade, consider enhancing JVM settings such as `heap-size`.

1. Select the Application Server node.
2. In the General Information page, click Add Cluster Support.
3. Review the implications of this procedure.
4. Click OK.

   The Admin Console displays a message that indicates that a restart is required.

5. Click Stop Instance.

   The Admin Console displays that the application domain has been shutdown.

6. If the CLI multimode is running (which means that you are running commands from the asadmin prompt), exit asadmin and restart.
7. Verify that the domain is stopped by using the `asadmin list-domains` command.
8. Start the newly upgraded cluster domain by using the `asadmin start-domain` command.
9. Launch the Admin Console.

   The common tasks page now includes cluster-related tasks, indicating that the domain now supports clustering features.