摘要
随着Web服务的广泛应用,服务质量(quality of service, QoS)已成为一个判定服务提供者是否成功的重要因素。QoS决定服务的可用性和效用,而这两方面都会影响到服务的普及。
本课题目的在于在满足用户基本需求及保证QoS约束的情况下定义流程中的每个Web服务,并且在流程执行时从注册中心中选择用户所需要的Web服务。用户对服务质量的要求影响了服务被选择的可能性。在服务查找过程中,消费者通过UDDI代理选择功能相同但质量较高的服务。但是单个Web服务的QoS约束并不能保证整条Web服务执行路径的全局QoS约束。由于每个用户对各QoS维度的需求不同,不同的用户对整条执行路径的QoS也有着不同的需求。
本文对基于QoS约束保证的Web服务合成进行了应用研究。基于UDDI的Web服务合成框架,给出了一种基于QoS约束保证的Web服务合成系统模型-WSCMQC(Web Service Composition Model based on QoS Constraints)。该模型既能在无约束状况下ASP.NET界面下实现最优QoS的Web服务工作流;提出了新的合成策略,运用QPSO算法实现支持QoS全局约束的Web服务合成的最优路径选择。实验表明,该算法实现选择的速度较快,准确性较高。
本文对Web服务在动态电子商务上的应用起到了抛砖引玉的作用,基于Web服务的整个领域―包括金融服务、高科技和媒体以及娱乐领域未来都将建立起支持QoS约束的服务收费机制以满足不同层次用户的需要。
QoS(quality of service) has become an important factor in the success of web service supplier with the widespread use of web services. Availability and utility of service is determined by QoS, and these two aspects will affect the popularity of service.
Our study aims to define every web service in the process. Services, which users need and must be constrained by QoS, will be selected from register center during the execution of process. The possibility of services’being selected is affected by user’s requirements of QoS. In the process of service discovery, consumers select services that have same functions but better quality through UDDI broker. However, global QoS constraints of the whole web service execution path cannot be guaranteed by individual services. The QoS need of whole execution path from various users differs certainly because of the different QoS dimension of respective users.
Applied research on web service composition supporting QoS constraints guarantee is studied in our thesis. With UDDI-based web service composition framework, a web service composition model based on QoS constraints, which is called WSCMQC (Web Service Composition Model based on QoS Constraints), is delivered. In this model, not only best but non QoS supporting web service workflow selection is carried out in ASP.NET, but also a new composition policy is put forward and best execution path selection of web service composition supporting QoS global constraints is achieved by QPSO algorithm. The experiment shows that selection implemented by this algorithm is comparatively fast and accurate.
This article intends to start further discussion on web service application in dynamic E-Commerce. In order to satisfy users from different levels, in the future, QoS supporting service charge mechanism will be established in the whole web service based area, including financial service, advanced technology, media and entertainment area.
引文
[1] Milanovic N, Malek M. Current solutions for Web service Composition[J]. IEEE Internet Computing, 2004, 18(6):51-59.
[2] Andrews et al. Business Process Execution Language for Web Services Version 1.1[EB/OL]. http://www-106.ibm.com/developerworks/webservices/library/ws-bpel/ (2003).
[3] R. Anane, K-M Chao, Y.Li, Hybrid Composition of Web Services and Grid Services[C]. IEEE International Conference on e-Technology, e-Commerce and e-Service, 2005
[4]王建峰,钱雪忠。基于中间件的Web服务和网格服务混合合成[J]。微计算机信息,2006,(21)。
[5] Anis Charfi , Mira Mezini. Aspect-Oriented Web Service Composition with AO4BPEL[J]. In Proc. ECOWS 2004,volume 3250 of LNCS, 2004
[6] Tao Yu, Kwei-Jay Lin. A Broker-Based Framework for QoS-Aware Web Service Composition[C]. Proceedings of the 2005 IEEE International Conference on e-Technology, e-Commerce and e-Service (EEE'05) on e-Technology, e-Commerce and e-Service, 2005
[7] Gerardo Canfora, Massimiliano Di Penta, Raffaele Esposito, etc. QoS-Aware Replanning of Composite Web Services[C]. proceedings of the 2005 IEEE International Conference on Web Services (ICWS 2005), 2005
[8] L. Zeng, B. Benatallah, A. H. H. Ngu, etc. QoS-aware middleware for Web services composition[J]. IEEE Transactions on Software Engineering, 30(5): 311-327,May 2004
[9] Aiqiang Gao, Dongqing Yang, Shiwei Tang, etc. Web Service Composition Using Integer Programming-based Models[C]. Proceedings of the 2005 IEEE international Conference on e-Business Engineering(ICEBE’05), 2005
[10]张春海,刘群。基于相对服务质量的Web服务集成策略[J]。计算机工程与应用, 2005,(06)。
[11] Gerardo Canfora, Massimiliano Di Penta, Raffaele Esposito, etc. An approach for QoS-aware service composition based on genetic algorithms[C]. Proceedings of the 2005 conference on Genetic and evolutionary computation (GECCO '05): 1069-1075, June 2005
[12] Leymann F, Roller D, Schmidt M T. Web Services and Business Process Management[J]. IBM System Journal, 2002, 41(2): 198-211.
[13]杨胜文,史美林。一种支持QoS约束的Web服务发现模型[J]。计算机学报,2005,(04)。
[14] Danilo Ardagna, Barbara Pernici. Global and Local QoS Constraints Guarantee in Web Service Selection[C]. Proceedings of the IEEE International Conference on Web Services (ICWS’05): 805-806, July 2005
[15] Kuo-Ming Chao, Muhammad Younas, Nathan Griffiths, etc. Analysis of Grid Service Composition with BPEL4WS[C]. Proceedings of the 18th International Conference on Advanced Information Networking and Application (AINA’04), March 2004
[16] M. Younas, K-M. Chao, R. Anane, etc. Grid Services Mediation[C]. Proceedings of the 19th International Conference on Advanced Information Networking and Applications (AINA’05), 2005
[17] Shalil Majithia, David W.Walker, W.A.Gray. Automated composition of semantic grid services[C]. International Conference on Autonomic Computing (ICAC'04), May 2004
[18] Zakaria Maamar, Soraya Kouadri Mostefaoui, Hamdi Yahyaoui. Toward an Agent-Based and Context-Oriented Approach for Web Services Composition[J]. IEEE Transactions on Knowledge and Data Engineering, 2005,17(5):686-697
[19] Yu-Tao,Lin Kwei-Jay. Service Selection Algorithms for Web Services with End-to-end QoS Constraints[C]. IEEE Global Telecommunications Conf.2003.3590—3595
[20] G Canfora, M Di Penta, R Esposito, etc. An Approach for QoS-aware Service Composition based on Genetic Algorithms[C]. Proc.of Genetic and Evolutionary Computation Conference(GECCO 2005), 2005
[21] Khalaf R, Mukhi N, Weerawarana S. Service-Oriented composition in BPEL4WS[C]. In:Proc.of the Int'l World Wide Web Conf.(WWW 2003).Budapest:ACM,2003.
[22]朱锦泉等。基于事务的工作流异常处理模型及方法[J]。吉林大学学报(G_学版) 2003,7 .第33卷第3期
[23] Michael C. Jaeger, Gregor Rojec-Goldmann, Gero Muhl. QoS Aggregation in Web Service Compositions[C]. 2005 IEEE International Conference on e-Technology, e-Commerce and e-Service (EEE'05): 181-185
[24] Michael C. Jaeger, Gregor Rojec-Goldmann, Gero Muhl. QoS aggregation for service composition using workflow patterns[C]. Proceedings of the 8th International Enterprise Distributed Object Computing Conference(EDOC 2004):149-159, 2004.
[25] Biplav Srivastava, Jana Koehler. Web Service Composition - Current Solutions and Open Problems[C]. ICAPS, 2003.
[26] Wohed, Petia, van der Aalst, etc. Web Services Composition Languages: The Case of BPEL4WS[C]. In Proceedings 22nd International Conference on Conceptual Modelling (ER), pages pp. 200-215, 2003.
[27] M. Cibran, B. Verheecke, W. Vanderperren, etc. Aspect-Oriented Programming forDynamic Web Service Selection, Configuration and Management[J]. World Wide Web Journal (WWWJ), Kluwer Academic Publishers, 2006.
[28] CAO J. Composing Web services based on agent and workflow [Z]. GCC,2003. 697-704.
[29]周根春,曹健,张申生等。基于约束Agent的面向服务性能的服务复合方案[J]。计算机集成制造系统-CIMS,2005,(08)。
[30] Ethan Cerami. Web Service Essential[M]. O’Reilly, 2002.
[31]岳昆,王晓玲,周傲英。Web服务核心支撑技术[J]。软件学报,2004,15(3):428-442
[32] W3C. SOAP Version 1.2[EB/OL]. http://www.w3.org/TR/2003/REC-soap12-part0-20030624, 2003
[33]尹向东。SOAP及在Web服务中的实现[J]。湖南科技学院学报,2005,(11)
[34]柴晓路。WSDL:描述你的Web服务[EB/OL]。http://www-128.ibm.com/developerworks/cn/webservices/ws-wsdl/, 2001
[35] Tom Bellwood. Understanding UDDI[EB/OL]. http://www-128.ibm.com/developerworks/library/ws-featuddi, 2002
[36]李景霞,侯紫峰。Web服务组合综述[J]。计算机应用研究,2005,(12)
[37] Sheila A. McIlraith, Tran Cao Son, and Honglei Zeng. Semantic Web Services[J]. IEEE INTELLIGENT SYSTEMS, v.16 n.2, p.46-53, March 2001
[38] Anbazhagan Mani, Arun Nagarajan. Understanding quality of service for Web services[EB/OL]. http://www-128.ibm.com/developerworks/library/ws-quality.html, 2002
[39]柴晓路。UDDI注册信息的数据模型[EB/OL]。http://www-128.ibm.com/developerworks/cn/xml/soap/index8.html, 2001
[40] lp_solve group. lp_solve API [EB/OL]. http://groups.yahoo.com/group/lp_solve/, 2006
[41]曾建潮,介婧,崔志华。微粒群算法[M],第一版,北京:科学出版社,(2004)10-19
[42] Sun, J. and Xu W.B.. A Global Search Strategy of Quantum-behaved Particle Swarm Optimization Proceedings of IEEE conference on Cybernetics and Intelligent Systems[J]. (2004)111– 116
[43] Sun, J. Feng B. and Xu W.B..Particle Swarm Optimization with Particles Having Quantum Behavior. Proceedings of 2004 Congress on Evolutionary Computation[J]. (2004) 325-331.
