I Am Going to Forget These

Shiver Me Meters

When you want to make use of event based meters (like vcpus) in your OpenStack Nova installation, make sure that the Nova compute service is telemetry enabled, i.e. its nova.conf has:

[DEFAULT]
...
instance_usage_audit = True
instance_usage_audit_period = hour
notify_on_state_change = vm_and_task_state
notification_driver = messagingv2

After performing this change you’ll have to restart the Ceilometer compute agent (which you can run with the ceilometer-polling --polling-namespaces compute command, by the way) and the Nova compute service.

Always true to form, I probabably forgot this simple configuration step for 5 or 10 times now and have built several widow’s walks while waiting for those elusive vcpus samples.

Relevant documentation: OpenStack Installation Guide for Ubuntu