Hello there,
I am more than happy to help you with this project but it seems like you're trying to solve your problem in a not very so efficient way. I think the alert mechanism is pretty reasonable however, changing DNS on the fly isn't a very good practice as you can use a reverse proxy which is better suited for the task. Can you please provide me with a little more details about your servers (including the DNS server) so I can see what we can do, however, if you're happy with your solution, I am more than happy and capable to get it done as you like.
Cheers,
omeid