Wildfly supports clustering out of the box & we need not install any special services/packages to get wildfly cluster working. Clustering refers to a number of applications running simultaneously & working together to create an application that provides increased scalablity, reliability with increased performance. We can create cluster of application that can be Horizontal scalable (for handling higher load), or we can create cluster that are highly available or we can create cluster to load balance the load we receive on our application.