Peaks and Sums

Measuring utilization of computing resources is more complex than simply determining the maximum memory or processor utilization.

Sum of Peaks. An old standby in capacity planning is to simply take the peak of the two loads and use that to determine the maximum required capacity; this is the “sum of peaks”. While this will definitely provide a robust solution, it does not take into account the timing of the peak of the loads and may end up planning more capacity than is actually used.

Peak of Sums. A more efficient planning solution, which is easily accomplished using HP Integrity Essentials Capacity Advisor, takes into account the timing of the maximum utilization peaks in the individual loads. By adding together utilization at each measured interval and then taking the maximum of the resulting time sequence, a more accurate measure of the required maximum resource can be determined. This can lead to cost savings when planning the resources required to consolidate loads onto new or existing servers.