To setup httpd with mod_cluster, refer to the mod_cluster docs:
I encourage you to also configure httpd w/mod_advertise. This way, you do not need to configure anything within AS7 itself. When using mod_advertise, your httpd instance will announce itself to your AS7 nodes.
To enable session replication, simply add <distributable/> to your web.xml. Once your application is deployed, the AS will automatically register your application with mod_cluster, and httpd will start directing traffic to your node. To customize load balancing behavior, refer again to the mod_cluster docs.
Oops - I didn't notice your post title, indicating that you're running on EC2.
In that case, you'll need to make the following modifications:
1. You cannot use mod_advertise, since multicast will not work. Remove the mod_advertise module entirely, and set advertise="false" within the mod_cluster subsystem in AS7.
2. Define the location of your httpd instance using the "proxy-list" attribute in the mod_cluster subsystem.
3. Change the default-stack of the jgroups subsystem to "tcp" instead of "udp".
4. Replace MPING with S3_PING within the "tcp" stack.
Mod_cluster solves my problem