Configuring Couchbase Server 4.0 Beta

I have configured Couchbase Server 4.0 Beta on four instances of AWS EC2. I have set up two instances to have data service running and one each for index and query service. [Multi Dimensional Scaling Now, when i set the cluster up, I set the hostname of each server as my public DNS, so that the servers can find each other across data centers. Everything works fine, till I shut my instances down.

When i start my instances again, couchbase servers don't start. I'm assuming this happens becaues my public DNS changes everytime I restart the server. This forces me to re-install couchbase every time i shut my instances down, and repeat the entire process of configuration again. I'm sure there must be an easy (and much better) alternative to this. Is there any way I can configure the hostname, and the hostname of all the servers in my cluster before starting any server?