Auto scaling, DNS, and EBS volumes
This is something I've been trying to figure out for a little while now. I'm deploying an array of Membase servers inside of Rightscale. I've got the array configured to have all configuration settings and data on an EBS volume that I take regular snapshots of. So far everything is pretty cut and dry and works well. Where I start to have problems is when I mix auto scaling with DNS. I want the array to be able to auto scale, but that causes problems with the MB_DNS_NAME input. Right now I'm not aware of how to create a new A record in DNSMadeEasy automatically, nor am I aware of how to get the DDNS ID on the fly if the first part was possible so when a new server spins up from the auto scaling feature, I don't have a value for the MB_DNS_NAME. The work around that I'm using right now is I'm using the EC2_HOSTNAME of the server as the MB_DNS_NAME. Doing this gives me the ability to auto scale the array and dynamically assign a DNS name that resolves to that particular server. The only problem with this is that it's causing problems when I try to create a new server from the latest snapshot. Since any new server that I launch has a new EC2_HOSTNAME, its creating a new EBS volume instead of restoring from an existing snapshot. I tried using the EBS_LINEAGE_PREFIX_OVERRIDE input while setting the INITIAL_LAUNCH value to false, but when the server was operational I could talk to it. All I would get is errors that the IP has changed when I look at the new server in the web console.
So would anyone have any suggestions on how to configure an auto-scalable array of Membase servers, with or without using DNSMadeEasy, that's still able to utilize EBS volumes for backup purposes?