How to properly clone an active MySQL database?

Question

MySQL

In the title, I tried to briefly outline the essence of the issue, but in fact it is more broad.
There is a site with about a couple of hundred thousand users, of which about five thousand are online.
All these users actively post data to the database, to different tables.
And then the cleaning lady in the DC touches the pilot and everything turns off.
But, we are cunning, we also have a DC and there is a fresh copy of the database. And she "looks" into the world, ready to receive and give data.
Question:
at what level do you start thinking about an up-to-date copy of the data?
At the API level, you can send requests to different databases (hosting, DC, domains).
Or are there options at the base level too? Or better at all levels?
Or maybe choose a decentralized option?
Please do not throw slippers, it will not say anything about me, I already know everything about myself.
I am looking for options for detailed assistance and advice on mutually beneficial terms.

Answer 1

replication