Using MetricAlarmExpression

The MetricAlarmExpression data object lets you set an alarm to monitor performance metrics. The vSphere Client uses the data object to indicate when hosts or clusters do not have sufficient resources in a DAS or DRS cluster environment. See the Resource Management Guide.

You set the metric property to the PerfMetricId of a performance metric that you want to monitor on the system. Set the red or yellow properties to identify the level at which the metric value moves from green, to yellow, to red. You must define red, yellow, or both properties. Use each of these properties with the isAbove or isBelow MetricAlarmOperator enumerations to complete the definition of the threshold.

In conjunction with red and yellow properties, you can use the redInterval or yellowInterval properties. These properties enable you to set the number of seconds that the performance metric must be in red or yellow state before the expression becomes true and triggers the defined action.