The input maximum (respectively minimum) being true corresponds to the state where the set of Dvfs reaches the maximum CPU frequency (respectively the minimum CPU frequency).
Another approach to improve energy efficiency for the IT subsystem is Dynamic Voltage and Frequency Scaling (DVFS), which reduces energy consumption by dynamically scaling the supplied voltages and adjusting the CPU frequency (according to the CPU workload).
Initially, only node 1 is on, self-sizing either turns node 2 on when node 1 is not able to handle all clients requests or off when clients requests can be treated by node 1. node 1 and node 2 have two CPU frequency levels which are 800MHz being their minimum CPU frequency and 1.20GHz being their maximum CPU frequency.
So when self-sizing detects an overload in lower CPU frequency, the adding operation it performs can be unnecessary if increasing the CPU frequency of the active machines before the adding operation is sufficient to support the workload.
It decreases the CPU-frequency when the CPU load of the machine is less than the minimum threshold if the minimum CPU frequency is not reached.
Without coordination, for Workload1 (Figures 15) as well as for Workload2 (Figures 16), the overload detection triggers adding operation and CPU frequency increase operation because the machine hosting the Tomcat server is at minimum CPU capacity.
Windows 8.1 manages the CPU frequency automatically.
User space-sets the CPU frequency specified by the user.
Once the CPU frequency is executed, the CPU utilization decreases.
If there is not enough energy to run the task, then it decreases the CPU frequency; otherwise, it runs the task with maximal CPU frequency.
Indeed the evaluation of an overload by self-sizing is relevant only in higher CPU frequency in which case the CPU frequency can no more be increased.
