For a long time I’ve wanted to know how MySQL scales as you add more memory to the server. Vadim recently benchmarked the effects of increasing memory and CPU core count. He looked for a balance between utilizing the hardware as much as possible, limiting the system complexity, and lowering the price-to-performance ratio.
The outcome of the research, which was sponsored by Virident, is that as you add CPUs and increase memory size, MySQL doesn’t scale as well as we would like, and solid-state storage — specifically, the Virident tachIOn drive — has more bandwidth than MySQL can fully utilize at present. Therefore, to decrease the price-to-performance ratio and increase the utilization of the tachIOn drive, Vadim sharded the database into smaller instances and colocated them on the same machine. It’s not a new approach, but to date I’m not aware of anyone measuring the different configurations the way Vadim has done.
You can read the full details in our Scaling MySQL With Virident Flash Drives and Multiple Instances of Percona Server white paper.