I was asked this question in an e-mail — feel free to ask your questions in the comments, as I will point the original author to this post to answer those questions. There is not a lot of data here, so instead of me asking questions in an e-mail I figured I would open it up to the (MySQL) world. Without further ado, here’s the question:
Basically when we open more than one connection- we’re opening 5, and we do processing in mysql (innodb tables) the server cpu and memory max out and the processing grinds to a halt. One connection at a time is able to run well- even with lots of data. But once we try to process data under 5 concurrent connections, mysql gets bogged down to the point where it’s barely usable.
I’ve researched this and found a number of opinions, including whether this is just poor