After you create a configuration, you must assign an Identity Server to it. For clustering, you can assign more than one Identity Server to the configuration. See Configuring a Cluster with Multiple Identity Servers. A configuration uses any shared settings you have specified, such as attribute sets, user matching expressions, and custom attributes that are defined for the server.
Click Devices > Identity Servers.
On the Servers page, select the server’s check box.
Click Actions > Assign to Cluster.
Select the configuration’s check box, then click Assign.
Restart Tomcat. The status icon for Identity Server must turn green. It might take several seconds for Identity Server to start and for the system to display the green icon.