Comment 2 for bug 1157261

I am going to submit a review momentarily that enables multiprocessing in keystone (i.e., multiple keystone processes on a host).

Note that you can also improve your keystone performance by using the Memcached backend instead of the default database backend. See instructions here: http://pic.dhe.ibm.com/infocenter/tivihelp/v48r1/topic/com.ibm.sco.doc_2.2/t_memcached_keystone.html.

Also note that I wrote an article on OpenStack performance a while ago that touches on these Keystone performance issues: http://blog.gridcentric.com/bid/318277/Boosting-OpenStack-s-Parallel-Performance