Issue

I have a server that had a processor consuming all CPU cycles this morning. There is evidence that it had been going on for at least several hours. I have an alert on that machine set to email me if any System Usage exceeds 90%, but I did not get the alert. Also, when I look at the history, it doesn't show System Load at higher than 9% at any time. Can you provide some guidance on how I might have the alert currently configured wrong? Or maybe I have the monitoring set up incorrectly?