Online Testing of Dynamic Reconfigurations w.r.t. Adaptation Policies

Abstract

Self-adaptation of complex systems is a very active domain of research with numerous application domains. Component systems are designed as sets of components that may reconfigure themselves according to adaptation policies, which describe needs for reconfiguration. In this context, an adaptation policy is designed as a set of rules that indicate, for a given set of configurations, which reconfiguration operations can be triggered, with fuzzy values representing their utility. The adaptation policy has to be faithfully implemented by the system, especially w.r.t. the utility occurring in the rules, which are generally specified for optimizing some extra-functional properties (e.g. minimizing resource consumption). In order to validate adaptive systems’ behaviour, this paper presents a model-based testing approach, which aims to generate large test suites in order to measure the occurrences of reconfigurations and compare them to their utility values specified in the adaptation rules. This process is based on a usage model of the system used to stimulate the system and provoke reconfigurations. As the system may reconfigure dynamically, this online test generator observes the system responses and evolution in order to decide the next appropriate test step to perform. As a result, the relative frequencies of the reconfigurations can be measured in order to determine whether the adaptation policy is faithfully implemented. To illustrate the approach the paper reports on experiments on the case study of platoons of autonomous vehicles.