Autonomic service-driven applications represent a new realm of software that can discover new capabilities, automatically integrate with other systems, and adapt to changing system environmental conditions. For the past many years, researchers and practitioners have been investigating, prototyping, and evaluating these self-configuring, self-healing, self-optimizing, and self-protecting systems. Although validation is expected to play a key role in the success of autonomic systems, there are few works that address this topic. Dynamic adaptation in autonomic software results in structural and behavioral runtime changes, which cannot be validated offline at design-time. Runtime testing has therefore emerged as a possible solution to validating dynamic adaptations in autonomic software. This chapter summarizes the state-of-the-art in runtime testing of autonomic systems, describes key challenges associated with runtime testing, and provides guidelines for integrating runtime testing approaches into autonomic software using self-testing architectures. Finally, directions for future research for validation of autonomic components are discussed.
