Cloned from launchpad blueprint https://blueprints.launchpad.net/nova/+spec/use-driver-usage-stats.

Description:

Currently nova-compute uses a resource tracker to track resource consumption. The resource tracker ignores usage stats reported by the driver and calculates resource consumption with an audit process, using information from the database. The driver already reports usage stats, but the values are ignored, which makes the audit process a redundant computation, with unnecessary queries to the database. Since the task is periodic, it has a compounding effect on performance. This blueprint will provide the option in nova.conf to use usage stats directly from the driver to report available resources, instead of  the auditing. As a side effect the available resources will reflect a more accurate stats in certain cases (i.e. existing/turned off VMs on a hypervisor before the installation of nova-compute).

Specification URL (additional information):

None