*6.1.* CPU *Utilization*

In the CPU utilization evaluation, data were collected from the following specific metrics: USR, which is the percentage of CPU used by the task during execution at the user level; SYS, which is the percentage of CPU used by the task during execution at the kernel level of the OS; WAIT is the percentage of CPU spent by the task while waiting to be executed; and finally, the CPU\_TOTAL, which is the total percentage of CPU time used by the task monitored by Pidstat tool, which provides statistics report for the tasks on GNU/Linux systems.

Figure 10 shows a peak of 180% of CPU\_TOTAL during the initialization of the Cluster, but with an average slightly above 100% during the entire experiment in the Minikube environment. It is also possible to notice in the graph a controlled behavior within Minikube about the metrics limits since the limit is only exceeded when starting the environment. Notice also that values of utilization higher than 100% in this context are related to the usage of more than one core of the processor by this process.

**Figure 10.** CPU utilization in Minikube.

Figure 11 shows a different behavior of K3S about Minikube regarding CPU utilization when we look at the CPU\_TOTAL metric, which, unlike Minikube, it shows an increase in CPU\_TOTAL utilization together with the USR metric over time, being interrupted when applying the cluster termination, which seems to act as a software rejuvenation technique for this situation. Although, during the entire experiment, the CPU\_TOTAL did not exceed 60%.

**Figure 11.** CPU utilization on K3S.
