# Glossary

alarm

  An action triggered whenever a meter reaches a certain threshold.

API server

  HTTP REST API service for Aodh.

HTTP callback

  HTTP callback is used for calling a predefined URL, whenever an alarm has been set off. The payload of the request contains all the details of why the alarm was triggered.

log

  Logging is one of the alarm actions that is useful mostly for debugging, it stores the alarms in a log file.

zaqar

  According to Zaqar Developer Documentation:

  > Zaqar is a multi-tenant cloud messaging and notification service for web and mobile developers.

project

  The OpenStack tenant or project.

resource

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

user

  An OpenStack user.

this page last updated: 2026-08-15 16:35:58

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