A similar question turned into opinion soup over here: How to optimise database architecture for high volume sites?, so maybe there's no 'right' answer to this, but I want to check with the community.

My client is about to launch a TV advert. They are expecting traffic in the 7-digit department over the coming month. My job is to ensure the server does not fall over.

My question: is it worthwhile to split the MySQL database onto a separate server, which only serves the database. I then want to have multiple servers which contain the codebase and serve apache, interfacing with the database box. All will be virtual containers.

I do NOT (think I) want to use multiple DB servers - seems it will introduce unnecessary complexity and potential errors/bottlenecks.

Am I wrong? Would welcome some experience opinions on this. Thanks.