Comment 8 for bug 1202749

Thanks for the reminder. After reviewed the code, it seems both pollster and notification are trying to update these attributes. See: https://github.com/openstack/ceilometer/blob/master/ceilometer/compute/notifications.py and https://github.com/openstack/ceilometer/blob/master/ceilometer/compute/pollsters/util.py#L94

So I need to investigate it more deeper to make sure if there is a race condition issue.