Choosing a database backend

Moving from Ceilometer to Gnocchi

Gnocchi represents a fundamental change in how data is represented and stored. Installation and configuration can be found in Installing Manually. Differences between APIs can be found here.

There currently exists no migration tool between the services. To transition to Gnocchi, multiple dispatchers can be enabled in the Collector to capture data in both the native Ceilometer database and Gnocchi. This will allow you to test Gnocchi and transition to it fully when comfortable. The following should be included in addition to the required configurations for each backend:


Disable Keystone Authentification for Gnocchi

In somes cases, it is possible to disable keystone authentication for Gnocchi to remove the overhead of token creation/verification when request authentication doesn’t matter. This will increase the performance of Gnocchi.

Example of configuration:


roles = admin
user_id = <ceilometer_user_id>
project_id = <ceilometer_project_id>
endpoint = <gnocchi_endpoint>

Legacy Storage


Ceilometer’s native database capabilities is intended for post processing and auditing purposes where responsiveness is not a requirement. It captures the full fidelity of each datapoint and thus is not designed for low latency use cases. For more responsive use cases, it’s recommended to store data in an alternative source such as Gnocchi. Please see Moving from Ceilometer to Gnocchi to find more information.


As of Liberty, alarming support, and subsequently its database, is handled by Aodh.


As of Newton, event storage support is handled by Panko.

The following is a table indicating the status of each database drivers:

Driver API querying API statistics
MongoDB Yes Yes
MySQL Yes Yes
PostgreSQL Yes Yes
HBase Yes Yes, except groupby & selectable aggregates