Research on Common-Cause Failures of Web Service Composition

Reliability is one of the most important quality dimensions for web services. Current reliability models for composite web service assume the statistical independence of its component web services, which is often not the case. In this paper, we research on the reliability correlation of component web services by identifying common-cause failures (CCF) and propose a tree-based reliability model for composite web service. We also present the method to estimate overall reliability of composite web service based on our reliability model. Evaluation shows that our method can improve the accuracy of reliability estimation for composite web service and is particularly valuable when designing fault-tolerant service-based system. Based on the proposed reliability model, we propose a QoS-aware service selection process that is CCF-aware. Thus to ensure the selected web services for the composition to meet the reliability requirement.