We provide a hosted CMS for our customers, and when they want to point their domain name to their hosted site, we currently instruct them to create an A record that points to our load balancer's IP address.
When those servers fell over, the act of bringing a backup up and running in a different location was trivial compared to trying to get all customers to change their A records.
So I was wondering how we could remove that needed step.
Can we have everyone create a CNAME instead? have everyone point it to sites.oursite.com, and then we can change the DNS for sites.oursite.com locally and not have to bother them?
That sounds feasible, but we still would have the delay of propagating the DNS changes across ISPs. Is there something else we could do with our host to prevent that? Flush the DNS record some way, or maybe not use DNS but let Apache run a script to figure out what IP address we currently want to point to? It'd be nice to be able to just change the IP address and almost instantly have our system being served from another location.