I have example.com managed by a DNS server that associates it to some IP address (ip1), owned by a first web server where the full site is hosted.
I also have a secondary webserver (with ip2) that hosts a "backup" site, with only the public pages (homepage, about, etc.) and with some other pages (signup, login etc.) that just show a "under maintanance" webpage. This is a very inexpensive and not very powerful machine, that I'll just use to see some static pages in case the real site is down...instead of a sad connection error / site not found error.
Now I'd like to find/configure a service that automatically redirects example.com to ip2 when the webserver that own ip1 goes down. I know I could manually change the DNS records so that example.com points to ip2, but I'd like to find something that is very fast and automatic (so that I don't need to wake up at night to do that).
Any idea, suggestion, guidance? Thanks!