I am trying to coordinate the move of a site from its current server to a new one. My original plan was to migrate the data to the new machine, which is already in place and the migration scripts tested successfully. I was planning to configure the original machine to proxy all requests to the new one, in order to ensure that anyone hitting the original machine before the DNS change fully propagates will still get proper response.
Someone made an alternative suggestion that I add the records for the new machine, without it actually serving any content. I was told that, under these circumstances, traffic would all hit the original IP. When the new records propagate, I am told I can turn off the old server and bring up the new server. I’m skeptical of trying this and having my migration in a half-way mode. Should I even attempt it or just stick to my original plan?
There is nothing wrong with your original plan.
It’s also a good plan when you don’t control the DNS server(s) that you use.
[Edit] Also, since this sounds like a production environment, it is never a good idea to try something you are not familiar and comfortable with in a production environment.
The second idea does not sound at all bad, but just not optimal in this case. Go with what you know works.