Technology > Features > Management > Alerts

Alerts

AggreGate has an extensive support for alerting, which is one of the essential tools in modern monitoring systems. Alerts notify system operators when something goes wrong in any part of a distributed system. Without alerts, an operator would have to constantly go around the system and click devices just “to make sure everything is OK”. Alerts make sure operators notice what they should notice.

Every user has their own set of alerts. Alerts can also be shared. An alert comprises:

• Triggers
• Notification Rules
• Corrective Actions
  

Alert Triggers

Every alert has one or more triggers defining when to raise it. These can be either event triggers or state triggers.

	Alert Configuration

Event trigger is raised when an event of a certain type conforms to the trigger condition. This condition is flexibly configured by an expression, allowing complex checkings. For example, a vehicle monitoring system may generate an alert if an impact event received from a vehicle controller indicates that impact strength exceeds a threshold. Event triggers have support for event correlation, allowing an alert to be activated by event of one type and deactivated by event of another type (correlative event).

State trigger can either be raised in response to a certain state, or to any change in the state of whatever is being monitored. State trigger periodically check a device or system property (also pointed by a custom expression). They have configurable hysteresis (deadband) time, for activating the alert only if the condition lasts longer than a certain time. For example, a state trigger may raise an alert if the temperature rises over 120 degrees for more than 3 minutes. In plus, state triggers support value flapping (frequent change) detection that is reported as a separate alert type.

Every trigger may check one or more devices or resources. Combined with the ability to set up multiple triggers per alert, this allows for very flexible alerts.

Notification Rules

Alert notifications inform humans about alert conditions and provide related information. Notifications can be in the form of:

• Popup messages to the operator. (May also prompt for acknowledgement)
• Custom sound.
• E-mail notifications (also to multiple recipients). Alerts may be acknowledged by replying to e-mail notifications.
• SMS notifications.
  

In plus, alert's corrective actions may implement any other notification schemes.