CPU Trigger

The CPU trigger can be used when a specific job needs to be executed when the amount of aggregated processor activity on the machine has stayed above or below a determined threshold. We configure this trigger using a few options with the first being the Trigger Threshold. The Trigger Threshold can be set to a value of either Above or Below. As might be expected, if we choose the Above value, then the machine will need to maintain processor utilization above the Threshold Amount. And of course, as you may guess, choosing the Below value would mean that the machine will need to maintain processor utilization below the threshold amount. The Threshold Amount is a percentage of aggregated processor utilization.

The option Seconds Between Checks is a value which controls the overall granularity of how soon the trigger may respond to changes in the processor utilization. The minimum or default value for this setting is 5 seconds. The option Seconds Before Triggering controls the period in which the aggregated processor activity must sustain the level of activity above or below the threshold before the trigger will respond. The requirements for this value will vary significantly based on your intended usage. For example, if your server regularly executes many long running jobs which may be processor intensive, then these may cause the trigger to respond prematurely to what you intend. Thus, successful usage of this trigger may require careful planning and tuning of these values.

Finally, the option for Seconds Between Triggers controls how often the trigger responds to the processor activity. Some jobs you may need to have execute every time your machine utilization is above 95 percent. An example might be if you created a custom module to check for one of your processes that is taking longer than it should and can be detected by high processor utilization. Other times you may need to limit the frequency at which this CPU trigger responds. You can do this by setting this to an appropriately high value. An example might be that you do not want to cause the trigger to respond more than once per hour, so you may set this value to 3600 seconds (or 1 hour).