Vitrage/Blueprints/deducedalarms

Overview

As discussed in the Template Condition Evaluation, template conditions are tested to see if they evaluate to true. When this happens, we need to perform the actions specified in the template. In this blueprint we discuss the Deduce Alarm template, which enables the creation of a new alarm after the condition is met. For example: a new alarm should be created on a specific resource as result of the raising of a different alarm on some other (possibly related) resource.

Template Details

The Deduce Alarm template describes an if-then flow. Specifically, if alarm X happens on resource A then raise a new alarm Y on resource B. The if portion includes a condition on the cloud state, which also specifies the relation between the different resources being considered. The then portion describes the new alarm and its parameters (name, message, etc.) and the resource which the new alarm should be raised on.

When the condition evaluates to "false", the alarm is disabled, though only if there is no other template raising this alarm. The alarms are raised via Ceilometer API.

Flow Example

When alarm X happens on resource A, raise new alarm Y on resource B.