How can i run a backup server for mysql site

[imported_Stephen]

If I have a large MySQL site running (Using over 500mb for the database) is there any way I could have another server running that would be a backup for the site?
So if one server went down, the other could take over instantly and still have an up-to-date database.

I know how to do this with a static site, but not dynamic, which is changing a lot

Thanks!