IncompatibleObjectVersion: Version 1.12 of Service is not supported:

[root@compute1 ~(keystone_admin)]#  systemctl status  openstack-nova-compute.service

openstack-nova-compute.service - OpenStack Nova Compute Server

   Loaded: loaded (/usr/lib/systemd/system/openstack-nova-compute.service; enabled)

   Active: inactive (dead) since Mo 2015-04-27 12:14:56 EDT; 4min 7s ago

  Process: 15797 ExecStart=/usr/bin/nova-compute (code=exited, status=0/SUCCESS)

 Main PID: 15797 (code=exited, status=0/SUCCESS)

Apr 27 12:14:56 compute1  nova-compute[15797]: executor_callback))

Apr 27 12:14:56 compute1  nova-compute[15797]: File "/usr/lib/python2.7/site-packages/oslo_messaging/rpc/dispatcher.py", line 186, in _dispatch

..

Apr 27 12:14:56 compute1 nova-compute[15797]: IncompatibleObjectVersion: Version 1.12 of Service is not supported

And in the dashboard or via CLI the state of the compute host is down (as expected).

Thx,
-Arash