Comment 7 for bug 1317174

I have hit this issue just recently, and solution what's recommended, only service what needs to be restarted on controller nodes is "consoleauth"

This workaround worked for me:

# on Controller host:
# remove icehouse-compat from nova.conf
openstack-config --del /etc/nova/nova.conf upgrade_levels compute

# restart nova services on Controller host
openstack-service restart openstack-nova-consoleauth