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 the docs use processes to improve performance.

Change-Id: I5375702f45ccb82c02ff2bba1eabda836d5d25eb

doc/source/apache-httpd.rst

@@ -66,8 +66,8 @@ Start or restart HTTPD to pick up the new configuration.
 Now configure and start the uwsgi services. Copy the
 `httpd/keystone-uwsgi-admin.ini` and `httpd/keystone-uwsgi-public.ini` files to
 `/etc/keystone`. Update the files to match your system configuration (for
-example, you'll want to set the number of threads for the public and admin
-servers).
+example, you'll want to set the number of processes and threads for the public
+and admin servers).
 
 Start up the keystone servers using uwsgi::
 

httpd/keystone-uwsgi-admin.ini

@@ -14,7 +14,7 @@ master = true
 enable-threads = true
 
 # Tune this to your environment.
-threads = 4
+processes = 4
 
 # uwsgi recommends this to prevent thundering herd on accept.
 thunder-lock = true

httpd/keystone-uwsgi-public.ini

@@ -14,7 +14,7 @@ master = true
 enable-threads = true
 
 # Tune this to your environment.
-threads = 4
+processes = 4
 
 # uwsgi recommends this to prevent thundering herd on accept.
 thunder-lock = true