For our SaaS web-app we have two identical servers in two geographically separated data centers.

FOO_1 is the production server and does real-time (MySQL master-slave) replication to its backup F00_2. We want our users to always go to THEFOO.COM which somehow points to the production server.

So even if FOO_1 dies, we can just switch THEFOO.COM to redirect to FOO_2 so the failure is transparent. This switch can be manual or automatic but without failback (if FOO_1 somehow becomes available again).

Is there a way to do this with DNS? I am getting stuck with ANAME and CNAMEs configuration. We don't use sub-domains, just straight domains.

If not, what are other options? Does it make sense to just have a web server at LOVELY_FOO.COM and just redirect all traffic? I also looked at load balancers but didn't see a solution for across data centers/network providers.