How to move from one VPS server to another (with a change of ip) without data desynchronization in the database?

Question

Nginx

Is it possible to somehow transfer users from the old server to the new one on the same site until the DNS cache has been updated for everyone?
At the .httaccess/NGINX level?

Answer 1

Option 1 - DB cluster between old and new server.
Option 2 - transferring the database to a new server and connecting to it for sites on both VPS
Option 3 - transferring the entire site and database to a new server and leaving reverse proxy on the old one for a while.

Answer 2

I will support option number three from my colleague Alexey Dmitriev - just leave proxying to the new hosting in the old place, and after a couple of days, making sure from the logs that no one else is coming, turn it off.