ArCMAPE: A Software Product Line Infrastructure to Support Fault-Tolerant Composite Services

A number of solutions use software fault tolerance techniques based on design diversity to create fault-tolerant composite services that leverage functionally equivalent services. Nevertheless, these solutions are not able to adapt themselves at runtime to cope with dynamic changes of user requirements and fluctuations in the quality of services (QoS). We propose a self-adaptive solution, called ArCMAPE, that leverages ideas from Software Product Line Engineering to support fault-tolerant composite services. In particular, we specify a feature model and product line architecture to capture the common and variable features among a number of software fault tolerance techniques based on design diversity. ArCMAPE provides software components implementing the common features; and a foundation on which plug-in components, or variable components, can be easily added to realise the target variable features. At runtime, ArCMAPE dynamically instantiates software fault tolerance techniques tailored to the specific needs of different clients and contexts by employing feature-based runtime adaptations. Outcomes obtained from an empirical study suggest the feasibility and efficiency of our solution to support self-adaptive, fault-tolerant composite services. We discuss the obtained outcomes and present directions for future work.