We should revisit the use of eventlet (hence green threads) as the basis of the thread model. We should talk about it's pros and cons, and alternatives, such as fall back to vanilla Python threads, or to use multiprocessing. This should apply to nova, glance and keystone. The locking mechanisms, including "FOR UPDATE" clauses in db, file based locks and in memory mutex/semaphore should be considered in the thread model change. (Session lead is Yun Mao)
