If you have a facebook application, and want to move from one server to another, requiring an IP change, as we did recently, you can follow this method to achieve a virtually no downtime move.
Your domain is MyApp.com (IP 22.214.171.124).
Your Facebook (FB) application MyApp.com/WelcomePage
You want to move to a different IP (126.96.36.199):
- create a new sub-domain old.MyApp.com pointing to 188.8.131.52
- change your FB app to point to old.MyApp.com/WelcomePage
- create a new sub-domain new.MyApp.com pointing to 184.108.40.206
- setup new server, do what you need to do, when ready, change FB app to point to new.MyApp.com/WelcomePage
- leave the old server online in case it is accessible outside of facebook, via http://www.myapp.com/ and forward all requests to new server
- change *.MyApp.com and http://www.myapp.com/ to point to 220.127.116.11
- 48hours later, take down your old sever
Overkill ??? yes, for many it could be but this allows you to run parallel servers while you test everything, and allows you to quickly and easily rollback in case the moves goes sour.