Design and Performance Guarantees in Cloud Computing: Challenges and Opportunities

In the last years, cloud computing received an increasing attention both from academia and industry. Most of the solutions proposed in the literature strive to limit the effect of uncertain and unpredictable behaviors that may occur in cloud environments, like for example flash crowds or hardware failures. However, managing uncertainty in a cloud environment is still an open problem. In such a panorama, the service provider is not able to define suitable Service Level Objectives (SLO) that are easy to measure, and control. In this work we analyze two of the critical problems that are encountered in cloud environments, but seldom discussed or addressed in the literature: (1) how to reduce the uncertainty providing suitable control interfaces at different levels of the computing infrastructure; (2) how to assess performance evaluation in order to get probabilistic guarantees for the SLOs. We here briefly describe the two problems and envision some possible control-theoretical solutions.