Dynamic Adaptation of Service-Based Systems: a Design for Adaptation Framework

A key challenge posed by the Next Generation Internet landscape, is that modern service-based systems need to cope with open and continuously evolving environments and to operate under dynamic circumstances. Dynamism is given by changes in the operational context, changes in the availability of resources and variations in their behavior, changes in users goals, etc. Indeed, dynamically discover, select and compose the appropriate services in open and expanding domains is a challenging task. Many approaches for self-adaptive systems have been proposed in the last decades. Unfortunately, although they support run-time adaptation, current approaches tend to foresee the system adaptation requirements and their related solutions at design-time. This makes them inadequate for the application in open environments, where components constantly join/leave the system, since they require for continuous involvement of IT and domain experts for the systems re-configuration. We claim that a new way of approaching the adaptation of systems is needed. In this dissertation, we propose a novel design for adaptation framework for modeling and executing modern service-based systems. The idea of the approach consists in defining the complete life-cycle for the continuous development and deployment of service-based systems, by facilitating (i) the continuous integration of new services that can easily join the systems, and (ii) the systems operation under dynamic circumstances, to face the openness and dynamicity of the environment. Furthermore, Collective Adaptive Systems (CAS) are spreading in new emerging contexts, such as the shared economy trend. Modern systems are expected to handle a multitude of heterogeneous components that cooperate to accomplish collective tasks. In these settings, an extension of our framework in the direction of CAS has also been defined. The core enablers of the proposed framework have been implemented and evaluated in real-world scenarios in the mobility domain. Promising evaluation results demonstrate their practical applicability.