21.2.3. Clustered JBoss EAP 6 About Clustered Instances

A clustered instance is an Amazon EC2 instance running JBoss EAP 6 with clustering enabled. Another instance running Apache HTTPD will be acting as the proxy for the instances in the cluster.
The JBoss EAP 6 AMIs include two configuration files for use in clustered instances, standalone-ec2-ha.xml and standalone-mod_cluster-ec2-ha.xml. Each of these configuration files provides clustering without the use of multicast because Amazon EC2 does not support multicast. This is done by using TCP unicast for cluster communications and S3_PING as the discovery protocol. The standalone-mod_cluster-ec2-ha.xml configuration also provides easy registration with mod_cluster proxies.
Similarly, the domain-ec2.xml configuration file provides two profiles for use in clustered managed domains: ec2-ha, and mod_cluster-ec2-ha.