# Alarms

## Info

Alarms bind alerting rules, entities, and notification plans into a logical unit. Alarms are responsible for determining a state (`OK`, `WARNING` or `CRITICAL`) based on the result of a Check, and executing a notification plan whenever that state changes. You create alerting rules by using the alarm DSL. For information about using the alarm language, refer to the reference documentation.

## Setup

Alarms are sub-resources of Entities:

    $alarmId = 'alAAAA';
    $alarm = $check->getAlarm();

For more information about working with Checks, please see the appropriate documentation.

## Attributes

Name | Description | Required? | Method
--- | --- | --- | ---
check_id | The ID of the check to alert on. | Required | `getCheckId()`
notification_plan_id | The ID of the notification plan to execute when the state changes. | Optional | `getNotificationPlanId()`
criteria | The alarm DSL for describing alerting conditions and their output states. | Optional | `getCriteria()`
disabled | Disable processing and alerts on this alarm | Optional | `isDisabled()` <`bool`>
label | A friendly label for an alarm. | Optional | `getLabel()`
metadata | Arbitrary key/value pairs. | Optional | `getMetadata()`

## Create Alarm

    $alarm->create(array(
        'check_id' => 'chAAAA',
        'criteria' => 'if (metric["duration"] >= 2) { return new AlarmStatus(OK); } return new AlarmStatus(CRITICAL);',
        'notification_plan_id' => 'npAAAAA'
    ));

## List Alarms

    $alarms = $entity->getAlarms();

    foreach ($alarms as $alarm) {
        echo $alarm->getId();
    }

## Update and delete Alarm

    // Update
    $alarm->update(array(
        'criteria' => 'if (metric["duration"] >= 5) { return new AlarmStatus(OK); } return new AlarmStatus(CRITICAL);'
    ));

    // Delete
    $alarm->delete();