How to organize a test database (MySQL)?

Question

MySQL

Good afternoon!
In general, the task is to make a test database, a complete clone of the combat one. It is necessary that when making changes to the production database, all changes on the fly are duplicated in the test one.
How can this be organized? The classic master-master and master-slave mechanisms are not suitable, because it is supposed that with a test DB it is possible to do anything.
Thank you.

Answer 1

It seems to me that "full clone" and "you can do anything with the test database" are mutually exclusive concepts. If you do not write to the test database - your version of the master slave, if you write, how can it be a copy of the working one?

Answer 2

And changes in a test DB are necessary this very second?
If it’s just a cron, you can dump it and pour it onto a test database once every 5 minutes, let’s say, or whatever you want.