openstack_auth.backend:Authorization Failed: [Errno 111] Connection refused

Error Log
-------------
DEBUG:openstack_auth.backend:Authorization Failed: [Errno 111] Connection refused

Solution
-----------
a) check whether "keystone" service is running or not

b) Do following steps, if "keystone" service is not running

#cd keystone

#Activate virtualenv

#source .venv/bin/activate

#Run keystone service

#./bin/keystone-all