Self-adaptation for energy efficiency in software systems

The ICT sector consumes a large portion of the total energy supply in the world. The increasing number of ICT users, services, and infrastructures also suggests that the energy consumption of the ICT sector will grow even more significantly in the coming years. As a matter of fact, software defines how ICT infrastructure should be utilized. Inefficiencies in software propagate easily throughout the entire system. Therefore, software should be the main focus of energy efficiency solutions in the ICT sector. Ideally, software systems should be alert to their own energy consumption during the execution, and if the resources availability changes, they must adapt themselves to the new situation. In this dissertation, we explore the relationship between energy efficiency and self-adaptability of software systems. We distinguish between architectural solutions and infrastructural solutions. As for the former, we use software architecture as the main instrument to carry over energy-related design decisions. As for the latter, we evaluate the effectiveness of optimization algorithms and software-defined infrastructures. Lastly, we introduce a domain model for self-adaptive software systems. The model includes both architectural and infrastructural concepts, which provides the reader with a clearer image of all ingredients to enable self-adaptability