I have an X domain that uses two NS, one master and another slave1, from the Equinix datacenter here in Brazil.
Will I change this domain to use other Amazon NS, how long does it take to take effect?
During this time, will every request continue to fall into the old "pointing" of the old NS?
Propagation
The spread of the nameservers can take up to 24 hours and depends on several factors. Among them is your ISP and TTL (time to live) set in the registry.
Requests
During the propagation process, the requests you make will return a response that matches the current record on the nearest DNS servers. So all answers will be given based on the old nameservers until the propagation is complete and there may be discrepancies between several DNS servers which is completely natural. That is, the same domain can point to two distinct servers in different locations. An ISP may also take a little longer to have the nameservers fully propagated.
As a rule I usually make the change in the late afternoon of Friday, because depending on the domain of the domain the same may not have the same use during the weekend.
If you migrate the site to another server I advise you to pass all content subject to changes at the end of the propagation (emails, database, among other dynamic data)
