Regression Detected in Kepler or kube-apiserver CPU Utilization Performance

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Regression detected from the following reports:

Report: https://sustainable-computing-io.github.io/kepler-metal-ci/kepler-stress-test-metrics.html

Details:
Significant Regression Detected

Detailed Analysis and Conclusion:
Upon reviewing the test results from the last two days, a significant performance regression is observed in the Kepler CPU utilization metrics. Specifically, the test results from 2024-07-31 show a drastic increase in both the mean Kepler CPU Utilization and the Standard Deviation (Std Dev) percentages.

1. Mean Kepler CPU Utilization:

   • On 2024-07-31 at 18:18:00Z, the mean CPU utilization jumped to 0.3280331034%, a substantial increase from the previous day's value of 0.0597766338% recorded at 2024-07-30T18:15:51Z.
   • A similar high value is observed in the subsequent test on the same day at 19:50:43Z, where the mean utilization was 0.3038928317%.

2. Standard Deviation (Std Dev):

   • Alongside the mean utilization, the Std Dev also saw a significant rise. On 2024-07-31 at 18:18:00Z, the Std Dev was recorded at 0.2598348881%, compared to 0.0362022150% on the previous day.
   • The test at 19:50:43Z on 2024-07-31 also showed a high Std Dev of 0.2290510851%.

These metrics indicate a significant performance regression, as both the mean CPU utilization and the variability in CPU utilization (as indicated by Std Dev) have increased dramatically. This suggests that the system's performance under load has become less predictable and potentially less stable, warranting further investigation into the causes of this regression and potential mitigation strategies.