Chapter 1. Introduction to autoscaling components

You can use Ceilometer to collect data about metering and event information for Red Hat OpenStack Platform (RHOSP) components.

The Ceilometer service uses three agents to collect data from RHOSP components:

The Ceilometer agents use publishers to send data to the corresponding end points, for example the time-series database service (gnocchi).

Gnocchi is a time-series database that you can use for storing metrics in SQL. The Alarming service (aodh) and Orchestration service (heat) use the data stored in gnocchi for autoscaling.

You can configure the Alarming service (aodh) to trigger actions based on rules against metrics data collected by Ceilometer and stored in gnocchi. Alarms can be in one of the following states:

Director uses Orchestration service (heat) templates as the template format for the overcloud deployment. Heat templates are usually expressed in YAML format. The purpose of a template is to define and create a stack, which is a collection of resources that heat creates, and the configuration of the resources. Resources are objects in Red Hat OpenStack Platform (RHOSP) and can include compute resources, network configuration, security groups, scaling rules, and custom resources.