Title: Service-level agreement-based QoS analysis for web services discovery and composition

Authors: Stephen J.H. Yang, Jia Zhang, Blue C.W. Lan

Addresses: Department of Computer Science and Information Engineering, National Central University, No. 300, Jhongda Rd., Jhongli City, Taoyuan County 32001, Taiwan. ' Department of Computer Science, Northern Illinois University, 1425 W. Lincoln Hwy. DeKalb, IL 60115–2825, USA. ' Department of Computer Science and Information Engineering, National Central University, No. 300, Jhongda Rd., Jhongli City, Taoyuan County 32001, Taiwan

Abstract: Quality-of-Service (QoS) in web services considers a service|s non-functional characteristics during service specification, discovery and composition. In order to facilitate the development of QoS-aware web services, we first develop a QoS-aware model, which contains a configurable and extensible set of QoS attributes including response time, throughput, reliability, availability and price. We also examine how to use ad hoc industry standard Service Level Agreements (SLAs) to carry QoS specifications for web services. Then, two alternative service selection methods, namely, absolute and relative matchmaking, are presented to discover candidate services based on the QoS data derived from SLA documents. Finally, according to the formal semantics of workflow patterns, we utilise the aggregative effects of QoS attributes to help perform QoS-aware service composition.

Keywords: quality of service; QoS; web services; service specification; service discovery; service composition; service level agreements; SLA; semantics; workflow patterns.

DOI: 10.1504/IJIEM.2007.011590

International Journal of Internet and Enterprise Management, 2007 Vol.5 No.1, pp.39 - 58

Published online: 04 Dec 2006 *

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