2015-08-04 02:13:50.934 1699 TRACE nova.openstack.common.threadgroup [u'Traceback (most recent call last):\n', u'  File "/usr/lib/python2.7/dist-packages/nova/conductor/manager.py", line 422, in _object_dispatch\n', u'  File "/usr/lib/python2.7/dist-packages/nova/objects/base.py", line 163, in wrapper\n', u'  File "/usr/lib/python2.7/dist-packages/nova/objects/instance.py", line 1142, in get_by_host\n', u'  File "/usr/lib/python2.7/dist-packages/nova/db/api.py", line 714, in instance_get_all_by_host\n', u'  File "/usr/lib/python2.7/dist-packages/nova/db/sqlalchemy/api.py", line 215, in wrapper\n', u'  File "/usr/lib/python2.7/dist-packages/nova/db/sqlalchemy/api.py", line 2380, in instance_get_all_by_host\n', u'  File "/usr/lib/python2.7/dist-packages/sqlalchemy/orm/query.py", line 2320, in all\n', u'  File "/usr/lib/python2.7/dist-packages/sqlalchemy/orm/query.py", line 2438, in __iter__\n', u'  File "/usr/lib/python2.7/dist-packages/sqlalchemy/orm/query.py", line 2451, in _execute_and_instances\n', u'  File "/usr/lib/python2.7/dist-packages/sqlalchemy/orm/query.py", line 2442, in _connection_from_session\n', u'  File "/usr/lib/python2.7/dist-packages/sqlalchemy/orm/session.py", line 854, in connection\n', u'  File "/usr/lib/python2.7/dist-packages/sqlalchemy/orm/session.py", line 860, in _connection_for_bind\n', u'  File "/usr/lib/python2.7/dist-packages/oslo_db/sqlalchemy/compat/handle_error.py", line 208, in contextual_connect\n', u'  File "/usr/lib/python2.7/dist-packages/oslo_db/sqlalchemy/compat/handle_error.py", line 219, in _wrap_pool_connect\n', u'  File "/usr/lib/python2.7/dist-packages/oslo_db/sqlalchemy/compat/handle_error.py", line 324, in _handle_dbapi_exception_noconnection\n', u'  File "/usr/lib/python2.7/dist-packages/oslo_db/sqlalchemy/compat/handle_error.py", line 215, in _wrap_pool_connect\n', u'  File "/usr/lib/python2.7/dist-packages/sqlalchemy/pool.py", line 338, in connect\n', u'  File "/usr/lib/python2.7/dist-packages/sqlalchemy/pool.py", line 644, in _checkout\n', u'  File "/usr/lib/python2.7/dist-packages/sqlalchemy/pool.py", line 440, in checkout\n', u'  File "/usr/lib/python2.7/dist-packages/sqlalchemy/pool.py", line 963, in _do_get\n', u'  File "/usr/lib/python2.7/dist-packages/sqlalchemy/pool.py", line 285, in _create_connection\n', u'  File "/usr/lib/python2.7/dist-packages/sqlalchemy/pool.py", line 411, in __init__\n', u'  File "/usr/lib/python2.7/dist-packages/sqlalchemy/pool.py", line 538, in __connect\n', u'  File "/usr/lib/python2.7/dist-packages/oslo_db/sqlalchemy/compat/handle_error.py", line 200, in connect\n', u'OperationalError: (OperationalError) (2005, "Unknown MySQL server host \'controller\' (2)") None None\n'].
2015-08-04 02:13:50.934 1699 TRACE nova.openstack.common.threadgroup