Exception based Dynamic Service Coordination Framework for Web Services

웹 서비스를 위한 예외 상황 기반 동적 서비스 연결 프레임워크

  • 한동수 (한국정보통신대학교 공학부) ;
  • 이성독 (한국정보통신대학교 공학부) ;
  • 정종하 (한국정보통신대학교 공학부)
  • Published : 2006.08.01

Abstract

Web services on the Internet are not always reliable in terms of service availability and performance. Dynamic service coordination capability of a system or an application invoking Web services is essential to cope with such unreliable situations. In dynamic service coordination, if a Web service does not respond within a specific time constraint, it is replaced with another Web service at run time for reliable invocation of Web services. In this paper, we develop an exception based dynamic service coordination framework for Web services. In the framework, all necessary information for dynamic service coordination is explicitly specified and summarized as a set of attributes. Then classes and workflows, supporting dynamic service coordination and invoking Web services, are automatically created based on these attributes. Developers of Web services client programs can make the invocations of Web services reliable by calling the methods of the classes. Some performance loss has been observed in the indirect invocation of a Web service. However, when we consider the flexibility and reliability gained from the method, the performance loss would be acceptable in many cases.

인터넷상에서 접근 가능한 웹 서비스는 가용성 및 성능적 측면에서 신뢰성이 항상 보장되지는 못한다. 동적 서비스 연결 (dynamic service coordination) 기법은 웹 서비스를 호출하는 시스템이나 응용 프로그램에서 이 같이 신뢰할 수 없는 상황에 대처할 수 있는 꼭 필요한 기술이다. 웹 서비스의 신뢰적인 호출을 보장해 주기 위해서 동적 서비스 연결 기법에서는 특정 웹 서비스가 정해진 시간 내에서 응답하지 못할 경우 실행 중에 해당 웹 서비스를 다른 웹 서비스로 대체하여 수행한다. 본 논문에서는 웹 서비스를 위한 예외 상황 기반 동적 서비스 연결 프레임워크를 제안한다. 이 프레임워크에서 동적 서비스 연결에 필요한 모든 정보들은 속성 (attributes) 집합 형태에 의해서 명시적으로 기술된다. 본 논문에서 고안된 동적서비스 연결 기법은 기술된 속성 정보를 기반으로 동적 서비스 연결이 가능한 클래스 또는 워크플로우를 자동으로 생성하고, 생성된 클래스 함수를 통해 웹 서비스를 간접적으로 호출함으로써 신뢰성 있는 웹 서비스 호출을 지원한다. 제안된 방식은 웹 서비스 호출 작업이 간접적으로 이뤄지기 때문에 이에 초래되는 약간의 성능적 손실을 피할 수는 없지만, 이 방법을 통해서 얻어지는 시스템의 유연성 (flexibility) 과 신뢰성 (reliability)를 고려할 때, 다소의 성능적 손실은 많은 경우에 있어서 허용될 수 있을 것으로 예상된다.

Keywords

References

  1. Application Architecture: A Critical Foundation for Service - Oriented Development and Web Services. White Paper, The Stencil Group and Wakesoft, http://www.wakesoft.com/product/WhitePapers.htmI, August 2003
  2. M. Gudgin, M. Hadley, N. Mendelsohn, J. J. Moreau and H. F. Nielsen, 'SOAP Version 1.2 World Wide Web Consortium Recommendation,' http://www.w3.org/TR/soap12-part1/, 2003
  3. E. Christensen, F. Curbera, G. Meredith and S. Weerawarana, 'Web Services Description Language (WSDL) 1.1 World Wide Web Consortium note,' http:/www.w3.org/TR/2001/NOTE-wsdl20010315, 2001
  4. D. Ehnebuske, B. McKee and D. Rogers, 'UDDI Version 2.04 API Specification,' http:/uddi.org/pubs/ProgrammersAPI-V2.04-Published-20020719.htm, 2002
  5. BPEL4WS Specification: Business Process Execution Language for Web Services Version 1.1, http:/www-128.ibm.com/developerworks/library/specification/ws-bpel, 2003
  6. I. Y. Ko, K. T. Yao and R. Neches, 'Dynamic Coordination of Information Management Services for Processing Dynamic Web Content,' Proceedings of the 11th International World Wide Web Conference, Honolulu, Hawaii, USA, May 7-11 2002 https://doi.org/10.1145/511446.511493
  7. L. J. Zhang, Q. Zhou and T. Chao, 'A Dynamic Services Discovery Framework for Traversing Web Services Representation Chain,' Proceedings of the IEEE Int. Conf. on Web Services (ICWS'04), June 6-9 2004 https://doi.org/10.1109/ICWS.2004.1314791
  8. M. M. B. Tariq and T. Kawahara, 'Introducing Dynamic Distributed Coordination in Web Services for Next Generation Service Platforms,' Proceedings of the IEEE Int. Conf. on Web Services (ICWS'04), June 6-9 2004 https://doi.org/10.1109/ICWS.2004.1314751
  9. C. Ellis, K. Keddara and G. Rozenberg, 'Dynamic change within workflow systems,' In Proc. of the Conf. on Organizational Computing Systems, August, pp. 10-21, 1995 https://doi.org/10.1145/224019.224021
  10. M. Reichert and P. Dadam, 'ADEPTflex-supporting dynamic changes in workflows without loosing control,' Journal of Intelligent Information Systems , Vol.10, No.2, pp, 93-129, March 1998 https://doi.org/10.1023/A:1008604709862
  11. G. Kappel, S. Rausch-Schott and W. Retschitzegger, Coordination in Workflow Management Systems - A Rule-based Approach, Coordination Technology for Collaborative Applications - Organizations, Processes, and Agents,' LNCS 1364, pp. 99-120, 1998
  12. A. Lazacano, G. Alonso, H. Schuldt and C. Schuler, 'The WISE Approach to Electronic Commerce,' International Journal of Computer Systems, Science, and Engineering, Vol.13. No.5, pp. 345-357, Sept. 2001
  13. M. Merz, B. Liberman and W. Lamersdorf, 'Using Mobile Agents to Support Interorganizational Workflow-Management,' International Journal on Applied Artificial Intelligence, Vol.11, No.6, pp, 551-572, Sept. 1997 https://doi.org/10.1080/088395197118064
  14. M. Merz, B. Liberman and W. Lamersdorf, 'Crossing Organizational Boundaries with Mobile ?Agents in Electronic Service Markets,' Integrated Computer-Aided Engineering, Vol.6 No.2, pp. 91-104, 1999
  15. J. Y. Shim, M. J. Kwak and D. S. Han, 'A Framework Supporting Dynamic Workflow Interoperation,' International Workshop on Modeling Inter-Organizaional Systems and Interoperability of Enterprise Software and Applications (MIOSINTEROP'05), Cyprus, 31 Oct.-4 Nov. 2005
  16. D. S. Han, J. Y. Goo, S. D. Song, S. D. Lee and B. S. Seo, 'Design of a Web Services Based eAI Framework,' 6th International Conference on Advanced Communication Tecnnology (ICACT 2004), Phoenix Park, Korea, Feb. 2004 https://doi.org/10.1109/ICACT.2004.1293018
  17. Y. K. Song and D. S. Han, 'Exception Specification and Handling in Workflow Systems,' LNCS 2642, pp. 495-506, 2003
  18. Y. Shi, L. J. Zhang and B. Shi, 'Exception Handling of Workflow for Web Services,' Proceedings of the 4th Int. conf. on Computer and Information Technology, pp. 273-277, 2004 https://doi.org/10.1109/CIT.2004.1357208
  19. U. Greiner and E. Rahm, 'Quality-Oriented Handling of Exceptions in Web services-Based Cooperative Processes,' Proc. Of EAI-Workshop 2004-Enterprise Applocation Integration, Oldenburg. GITO- Verlag, Berlin, pp. 11-18, 2004
  20. M. Kelin, A. Juan, Rodriguez-Aguilar and C. Dellarocas, 'Using Domain-Independent Exception Handling Services to Enable Robust Open Multi-Agent Systems: The Case of Agent Death,' Autonomous Agents and Multi-Agent Systems 7, pp. 179-189, 2003 https://doi.org/10.1023/A:1024145408578
  21. P. Johannesson, B. Wangler and P. Jayaweera, 'Application and Process Integration - Concepts, Issues, and Research Directions,' Information Systems Engineering Symposium '02, eds. S. Brinkkemper, E. Lindencrona, and A. Solvberg, Springer Verlag, 2000
  22. C. Szypersky, D. Gruntz and S. Murer, 'Component Software: Beyond Object-Oriented Programming,' 2nd edition, ACM Press, 2002