Ceilometer is designed to collect measurements from OpenStack services and from other external components. If you would like to add new meters to the currently existing ones, you need to follow the guidelines given in this section.
Three type of meters are defined in Ceilometer:
|Cumulative||Increasing over time (instance hours)|
|Gauge||Discrete items (floating IPs, image uploads) and fluctuating values (disk I/O)|
|Delta||Changing over time (bandwidth)|
When you’re about to add a new meter choose one type from the above list, which is applicable.
If you plan on adding meters, please follow the convention below:
Meters definitions by default, are stored in separate configuration file, called ceilometer/meter/data/meters.yaml. This is essentially a replacement for prior approach of writing notification handlers to consume specific topics.
A detailed description of how to use meter definition is illustrated in the admin_guide.
Ceilometer supports collecting notifications as events. It is highly recommended to use events for capturing if something happened in the system or not as opposed to defining meters of which volume will be constantly ‘1’. Events enable better representation and querying of metadata rather than statistical aggregations required for Samples. When the event support is turned on for Ceilometer, event type meters are collected into the event database too, which can lead to the duplication of a huge amount of data.
In order to learn more about events see the Events and Event Processing section.