Comment 2 for bug 1802400

What appears to be happening is that our testing sets the openstack-origin of nova-compute to the new release and then immediately sets the openstack-origin of ceilometer-agent to the new release too and then waits. However, it seems juju does not guarente the order that those two config-changed events fire. So in the case of this bug ceilometer-agent config-changed fired first and caused havoc.

Short term:
Document: Upgrade ceilometer-agent after nova-compute has finished in your deployment

Medium Term:
Make ceilometer-agent upgrades less destructive if they are triggered out of order.

Longer term:
Remove openstack-origin from ceilometer-agent and have upgrades triggered from the principle.