Keystone uwsgi performance tuning
Keystone uwsgi performance tuning

I ran some tests locally that showed that when using the uwsgi
deploy the keystone server wasn't using all the processes
available. When I switched from "threads" to "processes" the
concurrent performance improved considerably. So I'm proposing
that devstack switch to processes to improve performance.

Change-Id: I8cfe9272e098e636441b7cfb51bff08d62c3336e

group-policy/devstack,bswartz/devstack,bswartz/devstack,openstack-dev/devstack,noironetworks/devstack,nawawi/openstack,openstack-dev/devstack,dtroyer/devstack,richliu/devstack,group-policy/devstack,noironetworks/devstack,richliu/devstack,nawawi/openstack,dtroyer/devstack