How to have a constantly up-to-date mirror copy somewhere else?

Hi, we need to constantly access to our reservations database in the backend. Sometimes the server and database could stop working, so we are thinking to keep an exactly identical copy of the website on another server, so that we can see our reservations on the backup if something goes wrong with the official site.

Is there any way/plugin to push the content on 2 different databases at the same time?

thanks in advance