Chinese Journal of Computers   Full Text
Title	Modeling and Application of Data-Links Among Web Services
Authors	GU Zhi-Feng LI Juan-Zi HU Jian-Qiang XU Bin WANG Ke-Hong
Address	(Department of Computer Science and Technology, Tsinghua University, Beijing 100084)
Year	2008
Issue	No.8(1309—1318)
Abstract &   Background	Abstract Data correlations are relationships among I/O documents of Web services. They reflect the correlations among services on business logics, and are important to service tasks such as service composition, service discovery, and etc. Existing modeling methods of data correlation express data correlations indirectly by reasoning on data models or ontology models used by service interface definitions, and they have limitations on expressiveness. In order to solve this problem, referring to the idea of hyperlinks, this paper proposes the concept of Explicit Data-Link, which expresses data correlations as static explicit declarations. It first gives the abstract model of explicit data-link and its XML implementation. Then, the application of explicit data-link is discussed in detail. A study case that makes use of explicit data-link to optimize the composition algorithm for WS-Challenge 2007 is given. The experiment results show that this optimization method is effective when dealing with data sets that have complex inheritance structures, and the algorithm wins the championship of performance in the competition. Keywords data correlation; Web service; WSDL; service description; WS-Challenge Background Service-oriented computing (SOC) has been widely accepted as the next generation programming paradigm. It defines promising technologies that enable future computing models over the Internet. It is obvious that the information encoded in service model is the basis of high-level technologies, and many works have tried to define extended service models to support advanced service technology. This paper introduces another extended model, so-called explicit data-link, for the modeling of data correlations among Web services. Unlike existing works, which usually model data correlations in an implicit way, and create them dynamically by reasoning on the data models or ontology models used by service definitions, the authors’ method defines a way to express data correlations with static explicit declarations, which makes it more expressive than existing methods. This work is supported by the National Basic Research Program of China (973 Program) under grant Nos.2007CB310803, 2003CB317007, the National High Technology Research and Development Program (863 Program) under grant No.2007AA010306, National Natural Science Foundation of China (NSFC) under grant No.190604025, and China Postdoctoral Science Foundation under grant No.20070410061. These foundations cover a lot of research topics, while all of them adopt SOC as the infrastructure, which is the research topic of this work. This work is also inspired by the WS-Challenge competition. The authors have taken part in WS-Challenge 2006 and 2007. In WS-Challenge 2006, they won the championship of syntactic composition, and won the number 4 of semantic composition. WS-Challenge 2007 only held semantics composition, and they won the championship in this time. Now the authors are preparing for the coming WS-Challenge 2008.