By default, if no value is reported, the associated monitoring attribute is set to inactive, and assigned the message Value is obsolete. This means that, by default, failure to report a value does not lead to an alert.
This setting is often not sensible, especially for components for which values are reported to the Monitoring Architecture by active data suppliers. This means that if a problem occurs in this component that is so serious that the active data supplier no longer supplies values, it can also no longer report an alert ‑ values would simply not be reported, and the associated component would eventually be set to inactive.
You can therefore define in the general properties of a monitoring attribute, that a heartbeat alert is additionally triggered if the reporting of values fails for the monitoring attribute.
A heartbeat alert is triggered because no value has been reported, and not because the currently reported value has exceeded a threshold value. Heartbeat alerts are therefore not displayed in the Current Status view, but only in the Open Alerts view and in the Alert-Browser (see Display Types and Views of the Alert Monitor).
If no values are reported any more for the desired monitoring attribute (for example, if the associated data supplier is no longer functioning), a heartbeat alert is generated and is displayed in the Open Alerts view and in the Alert Browser. The heartbeat alert is always a red alert and has the following text: Heartbeat Alert: value older than <number> seconds.
Exactly one alert is triggered when the configured time period is exceeded. The measurement is restarted after a new value is reported. This ensures that only one alert occurs for each time the threshold value is exceeded, and that an alert is generated each time that the threshold value is exceeded.
Note that other properties of the monitoring attribute must not prevent the generation of a heartbeat alert:
Using the heartbeat alert for a log attribute (Workload Collector Monitor)
Scenario: The Collector Is No Longer Running
Without activation of a heartbeat alert, no alert is generated:
With the activation of a heartbeat alert, an alert is generated, and displayed in the Open Alerts view: