aodh/doc/source/glossary.rst
Julien Danjou 7a99c9c61e Update glossary
Change-Id: I28efc3de64c9390b3fed53dcd9eb6fb1b1af0490
2013-07-05 11:46:54 +02:00

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Glossary

agent

Software service running on the OpenStack infrastructure measuring usage and sending the results to the collector.

alarm

An action triggered whenever a meter reaches a certain threshold.

API server

HTTP REST API service for ceilometer.

ceilometer

From Wikipedia1:

A ceilometer is a device that uses a laser or other light source to determine the height of a cloud base.

central agent

Software service running on a central management node within the OpenStack infrastructure measuring usage and sending the results to the collector.

collector

Software service running on the OpenStack infrastructure monitoring notifications from other OpenStack components and samples from the ceilometer agent and recording the results in the database.

compute agent

Software service running on a compute node within the OpenStack infrastructure measuring usage and sending the results to the collector.

data store

Storage system for recording data collected by ceilometer.

meter

The measurements tracked for a resource. For example, an instance has a number of meters, such as duration of instance, CPU time used, number of disk io requests, etc. Three types of meters are defined in ceilometer: * Cumulative: Increasing over time (e.g. disk I/O) * Gauge: Discrete items (e.g. floating IPs, image uploads) and fluctuating values (e.g. number of Swift objects) * Delta: Incremental change to a counter over time (e.g. bandwidth delta)

notification

A message sent via an external OpenStack system (e.g Nova, Glance, etc) using the Oslo notification mechanism2. These notifications are usually sent to and received by Ceilometer through the notifier RPC driver.

non-repudiable

From Wikipedia3:

Non-repudiation refers to a state of affairs where the purported maker of a statement will not be able to successfully challenge the validity of the statement or contract. The term is often seen in a legal setting wherein the authenticity of a signature is being challenged. In such an instance, the authenticity is being "repudiated".

project

The OpenStack tenant or project.

resource

The OpenStack entity being metered (e.g. instance, volume, image, etc).

sample

Data sample for a particular meter.

source

The origin of metering data. This field is set to "openstack" by default. It can be configured to a different value using the counter_source field in the ceilometer.conf file.

user

An OpenStack user.


  1. http://en.wikipedia.org/wiki/Ceilometer↩︎

  2. https://github.com/openstack/oslo-incubator/tree/master/openstack/common/notifier↩︎

  3. http://en.wikipedia.org/wiki/Non-repudiation↩︎