2. Database Performance: First Pass, mostly Synthetics + random STAR Jobs

Test results :
 - unconstrained *synthetic* test using SysBench shows that new nodes
perform ~x10 times better than old ones (mostly due to x2 more ram
available per core => larger mysql buffers, fs cache etc);
 - real bfc job tests (stress-test of 100 simultaneous jobs, random
stream daqs) show performance similar to old nodes, with ~5% less time
spent in db (rough estimation, only able to run that 100 jobs test twice
today). Similar disk performance assumes similar db performance for
those random streams, I guess..
 - nightly tests do not seem to affect performance of those new nodes
(negligible load vs. twice the normal load for old nodes).