So, thinking about the "standard" MySQL scale-out approach of master/slave coupled with memcached, what's the new best practice if you have a stack of iodrives sitting around?
Well, I think you're probably solving a different problem with the master/slave. If you're scaling out and caching because you're CPU limited then nothing changes. If you're scaling out because your disks can't keep up with the parallel read/write traffic then I'm thinking you can drop the cache and master/slave in many cases (unless you want the hot server for HA).
I worked on a pretty big site where we read from the slaves and wrote to the master, but we were still on 4.1 with MyISAM. Given the current size of the iodrives we would have to shard a lot more than we were, especially for a few large tables. But, it would drastically reduce deployment complexity.
