I have a growing website which now uses a single and ordinary MySQL server for its tasks. I wonder how and when should I migrate to more powerful servers or in other words when is the best time to use mirror servers or grid or other than single serving server?
How could I find out that my web apps need a better database server solutions and configurations? I know I can study usage and server loads, but since I don't have enough experiences on managing and developing large scale websites I need some advices on how to configure MySQL server(s) for a fast growing website? what are the best practices?