Hello, I am working on Watcher and we are currently changing how metrics are retrieved from different datasources such as Monasca or Gnocchi. Because of this major overhaul I would like to validate that everything is working correctly. Almost all of the optimization strategies in Watcher require the cpu utilization of an instance as metric but with newer versions of Ceilometer this has become unavailable. On IRC I received the information that Gnocchi could be used to configure an aggregate and this aggregate would then report cpu utilization, however, I have been unable to find documentation on how to achieve this. I was also notified that cpu_util is something that could be computed from other metrics. When reading https://docs.openstack.org/ceilometer/rocky/admin/telemetry-measurements.htm... the documentation seems to agree on this as it states that cpu_util is measured by using a 'rate of change' transformer. But I have not been able to find how this can be computed. I was hoping someone could spare the time to provide documentation or information on how this currently is best achieved. Kind Regards, Corne Lukken (Dantali0n)