Developing aerospace applications with a reliable Web services paradigm

One of the latest achievements of the Internet usage is the availability of Web services technology. Web services provide an efficient and convenient way for service provisioning, exchanging and aggregating, which facilitates a resourceful platform for the aerospace industry. The aerospace industry usually involves products of complex synthesis of various technologies and sciences. These different technical resources can be provided in the form of Web services to increase their availability, efficiency and performance. However, in aerospace area, reliability is an ultimately important issue. In this paper, we target on providing a reliable Web service paradigm for the industry. We describe the methods of reliability enhancement by redundancy in space and redundancy in time, identify parameters impacting Web service reliability, and present a Web service composition algorithm. The replication algorithm and the detailed system configuration are described. The Web services are coordinated by a replication manager, which schedules the workload of the Web services and keeps updating the availability of each Web service. We also perform a series of experiments employing several replication schemes and compare them with a non-redundant single service to evaluate the reliability of the proposed paradigm. Finally, we also model the Web services with Petri-Net and Markov chains to demonstrate the performance and reliability of the Web services.