I am going to migrate a site from one server to another. The site has a good bit of realtime transaction activity reading/writing to a backend database.
I believe I should ratchet down the TTL in the DNS on the domain so that once I am ready to make the switch all I need to do is update the nameservers assigned to the domain name and traffic will begin to move to the new server.
If my understanding of the process is correct, what should I set the TTL to on my current server?
Do I also need to set the "refresh", "retry", and "expire" values on my old server? If so, what should they be set too?
HERE's MY PROCESS
www.blah.com is hosted at hosting service provider "hoster
www.blah.com has its ns1 record as ns1.myFirstNameServer.net and its ns2 record as ns2.myFirstNameServer.net
I setup a new name server with ns records as ns1.aNewNameServerIdecidedToBuy.net and ns2.aNewNameServerIdecidedToBuy.net -- its IPs point to my current server at current "hoster"
Both my name server domains (myFirstNameServer.net and aNewNameServerIdecidedToBuy.net) are setup and reside with my registrar in their dns setup -- its IPs point to my new server at new "hoster"
Once I am ready to make the switch, I will logon to my registrar and change the nameserver setting on www.blah.com as follows: