WIldFly enables high availability of a Java EE application using session failover and load balancing. Session failover allows uninterrupted access to an application, even in the presence of a node failure. Load balancing allows for a timely response from the application, even in the presence of high volume requests.
WildFly can operate in standalone mode which is an independent process, much like JBoss Application Serer 3, 4, 5, and 6. It can also operate in managed domain mode where mulitple WildFly 8 instances across different physical or virtual hosts can be managed from a single control point.
Centralized administration and high availability together provides a very powerful combination for Java EE application deployments. This blog contains a video tutorial explaining that. Specifically, it shows:
Introduction to WildFly and Managed Domain concepts
Setup up a 2-instance cluster
Deploy a WAR file to the cluster using centralized administration from admin console
Access the application on one node and add HTTP session attributes on it
Shutdown that instance and show HTTP session failover by accessing the application on other instance