.. Copyright 2013 Nicolas Barcet for eNovance Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. .. _choosing_db_backend: ============================ 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 :ref:`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:: [DEFAULT] meter_dispatchers=database meter_dispatchers=gnocchi event_dispatchers=gnocchi 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:: [dispatcher_gnocchi] auth_section=service_credentials_gnocchi [service_credentials_gnocchi] auth_type=gnocchi-noauth roles = admin user_id = project_id = endpoint = .. _Gnocchi: http://gnocchi.xyz .. _here: https://docs.google.com/presentation/d/1PefouoeMVd27p2OGDfNQpx18mY-Wk5l0P1Ke2Vt5LwA/edit?usp=sharing Legacy Storage ============== .. note:: 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. .. note:: As of Liberty, alarming support, and subsequently its database, is handled by Aodh_. .. note:: As of Newton, event storage support is handled by Panko_. .. _Aodh: http://docs.openstack.org/developer/aodh/ .. _Panko: http://docs.openstack.org/developer/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 ================== ============================= ===========================================