From 894dfa0d7e0ff4d2dcce9ed842b2f6bb317355c2 Mon Sep 17 00:00:00 2001 From: David TARDIVEL Date: Tue, 19 Jan 2016 15:01:40 +0100 Subject: [PATCH] Add reference to Ceilometer developer guide Strategies can require, from Watcher, metrics collected on the IAAS. Watcher uses only Ceilometer API to retrieve metrics. Change the metrics database backend, add a new metric is not in the scope of Watcher, but rather in the Ceilometer one. We add some links to Ceilometer documentation about these topics. Change-Id: If37c7df8e5852f5ecf94b4a9eb9c8c91fe6637eb --- doc/source/dev/strategy-plugin.rst | 26 ++++++++++++++++++++------ 1 file changed, 20 insertions(+), 6 deletions(-) diff --git a/doc/source/dev/strategy-plugin.rst b/doc/source/dev/strategy-plugin.rst index d91014e36..61df43ec3 100644 --- a/doc/source/dev/strategy-plugin.rst +++ b/doc/source/dev/strategy-plugin.rst @@ -128,13 +128,27 @@ check/configure the latter so your new strategy can be fully functional. Querying metrics ---------------- -The metrics available depend on the hypervisors that OpenStack manages on -the specific implementation. You can find the metrics available per hypervisor -and OpenStack release on the OpenStack site. +A large set of metrics, generated by OpenStack modules, can be used in your +strategy implementation. To collect these metrics, Watcher provides a +`Helper`_ to the Ceilometer API, which makes this API reusable and easier +to used. -There are different possible ways to obtain usage metrics in Watcher, you can -use the default Ceilometer API or our Helper. -The Helper attempted to make the Ceilometer API more reusable and easy to use. +If you want to use your own metrics database backend, please refer to the +`Ceilometer developer guide`_. Indeed, Ceilometer's pluggable model allows +for various types of backends. A list of the available backends is located +here_. The Ceilosca project is a good example of how to create your own +pluggable backend. + + +Finally, if your strategy requires new metrics not covered by Ceilometer, you +can add them through a Ceilometer `plugin`_. + + +.. _`Helper`: https://github.com/openstack/watcher/blob/master/watcher/metrics_engine/cluster_history/ceilometer.py#L31 +.. _`Ceilometer developer guide`: http://docs.openstack.org/developer/ceilometer/architecture.html#storing-the-data +.. _`here`: http://docs.openstack.org/developer/ceilometer/install/dbreco.html#choosing-a-database-backend +.. _`plugin`: http://docs.openstack.org/developer/ceilometer/plugins.html +.. _`Ceilosca`: https://github.com/openstack/monasca-ceilometer/blob/master/ceilosca/ceilometer/storage/impl_monasca.py Read usage metrics using the Python binding -------------------------------------------