Comment 2 for bug 1538251

Keystone log (/var/log/keystone/main.log) contains records like this:
2016-01-27 08:38:57.828 36981 DEBUG keystone.common.cache._memcache_pool [req-35b16ccf-07dd-475f-84dc-85c2195b452e - - - - -] Memcached pool 139834131256456, thread 139834280691456: Marked host localhost:11211 dead until 1453883997.83 _debug_logger /usr/lib/python2.7/dist-packages/keystone/common/cache/_memcache_pool.py:115
meaning that memcached was expected at localhost.

As side effect the overall duration of request is 0.7 - 0.8 seconds on bare-metal:
192.168.0.205 - - [27/Jan/2016:08:38:57 +0000] "GET /v3/auth/tokens HTTP/1.1" 200 7675 774871 "-" "python-keystoneclient"