Any simple guide to setup clustering?

Hi, I'm using OpenFire as chat server, I'm amazed how smooth was it to setup. It also look easy to manage.

I've a project to setup OpenFire clustering. I searched the Internet but couldn't find much help. especially with using the new hazelcast plugin.

What I understand that I have to setup:

1. Two OpenFire servers

2. One database

3. A load balancer

My server is basically working and servers appears in clustering configuration.

My question is, should my servers share the same domain name? server.example.com or server1 & server2 @ example.com?

Do you prefer any guide on this subject?

Regards,

WM