The telemetry module has been fully integrated since the launch of OpenStack's Grizzly release. The project named Ceilometer provides an expandable monitoring and metering platform for OpenStack.
Note
The Ceilometer naming concept originally comes from light device technology to detect and measure the height of the cloud generally used in a plane metering system.
Ceilometer was originally intended (due the Folsom release) to collect usage data and transform it into billable items so that the cloud operator would be able to create the customer's invoice.
The Ceilometer project has been intensively developed and has enlarged its features to cover more measurement purposes for other needs in OpenStack. The primary targets of Ceilometer can be seen as follows:
Customer billing
System infrastructure monitoring
System infrastructure alerting