Take a look at the new version of this page: [ beta version ]. Tell us what you think.

ABSTRACT

Workflow is a collection of tasks that belong together in order to achieve a certain business goal. The workflows in which tasks are comprised of the execution of Web services are called Internet-based workflows. Analogous with transactions the correct execution of workflows requires workflows instances to be executed in an atomic and isolated way. Although the issue of the atomicity of Internet-based workflows is well understood and widely studied, the role of concurrency control is not neither well understood nor well studied in this context. In this paper, we restrict ourselves on this problem. The corner stone in our approach is the Workflow database, which stores information about the states of active workflow instances. The key idea is to control the interleaving of workflow instances by controlling the updates of the Workflow database by SQL-constraints. A gain of this approach is that the workflow isolation requirements nicely match the expression power of SQL-constraints, which in turn makes it possible to achieve a high degree of concurrency. In addition, workflow concurrency control can be easily implemented by utilizing the services of the underlying relational database management system.

REFERENCES

• 1: Dan C. Marinescu, Internet-Based Workflow Management: Towards a Semantic Web, John Wiley & Sons, Inc., New York, NY, 2002
• 2: Newcomer, E.: "Understanding Web Services", Addison-Wesley. 2002.
• 3: Mike P. Papazoglou , Willem-Jan Heuvel, Service oriented architectures: approaches, technologies and research issues, The VLDB Journal — The International Journal on Very Large Data Bases, v.16 n.3, p.389-415, July 2007 [doi>10.1007/s00778-007-0044-3]
• 4: Singh, M., Huhns, M.: "Service Oriented Computing: Semantics, Processes, Agents". John Wiley &Sons, Ltd. 2005.
• 5: Philip A. Bernstein , Vassco Hadzilacos , Nathan Goodman, Concurrency control and recovery in database systems, Addison-Wesley Longman Publishing Co., Inc., Boston, MA, 1987
• 6: Jim Gray , Andreas Reuter, Transaction Processing: Concepts and Techniques, Morgan Kaufmann Publishers Inc., San Francisco, CA, 1992
• 7: Nancy A. Lynch, Multilevel atomicity—a new correctness criterion for database concurrency control, ACM Transactions on Database Systems (TODS), v.8 n.4, p.484-502, Dec. 1983 [doi>10.1145/319996.319999]
• 8: Hector Garcia-Molina, Using semantic knowledge for transaction processing in a distributed database, ACM Transactions on Database Systems (TODS), v.8 n.2, p.186-213, June 1983 [doi>10.1145/319983.319985]
• 9: Mohammad Alrifai , Peter Dolog , Wolfgang Nejdl, Transactions Concurrency Control in Web Service Environment, Proceedings of the European Conference on Web Services, p.109-118, December 04-06, 2006 [doi>10.1109/ECOWS.2006.37]
• 10: Choi, S., Jang, H., Kim, H., Kim, J., Kim, S., Song, J., Lee, Y.: "Maintaining consistency under isolation relaxation of web services transactions". Proceedings of 6th International Conference on Web Information Systems Engineering, In Lecture Notes in Computer Science, 245--257. 2005.
• 11: Guabtni, A., Charoy, F., Godart, C.: "Concurrency management in transactional web services coordination". Database and Expert Systems Applications, 17th International Conference, DEXA 2006. In Lecture Notes in Computer Science, pages. 592--601. 2006.
• 12: Puustjärvi, J., "Concurrency control of Internet-based workflows". In Proc of the Sixth International Conference on Information Integration and Web-based Applications & Services (iiWAS2004), pages 647--654. 2004.
• 13: Ding, X., Wei, J., Huang, T.: "User-defined atomicity constraint: A more flexible transaction model for reliable service composition". Proceedings of 8th International Conference on Formal Engineering Methods, In Lecture Notes in Computer Sciences, pages 168--184. 2006.
• 14: Wenbing Zhao , L. E. Moser , P. M. Melliar-Smith, A Reservation-Based Coordination Protocol for Web Services, Proceedings of the IEEE International Conference on Web Services, p.49-56, July 11-15, 2005 [doi>10.1109/ICWS.2005.14]
• 15: Puustjärvi, J., "CWS-transactions: An approach for composing web services". Second International Conference on Web Information Systems and Technologies (WEBIST), pages, 69--74. 2006.
• 16: Fauvet, M., Duarte, H., Dumas, M., Benatallah, B.: "Handling transactional properties in web service composition". Proceedings of 6th International Conference on Web Information Systems Engineering, In Lecture Notes in Computer Sciences, pages 273--289. 2005.
• 17: Benjamin A. Schmit , Schahram Dustdar, Towards TransactionalWeb Services, Proceedings of the Seventh IEEE International Conference on E-Commerce Technology Workshops, p.12-20, July 19-19, 2005 [doi>10.1109/CECW.2005.26]
• 18: Xu, W., Cheng, W., Liu, W.: "A transaction-aware coordination protocol for web services composition". Proceedings of 7th International Conference on Web Information Systems Engineering, Wuhan, In Lecture notes in Computer Science. Springer, pages 126--131. 2006.
• 19: Muhammad Younas , Kuo-Ming Chao, A tentative commit protocol for composite web services, Journal of Computer and System Sciences, v.72 n.7, p.1226-1237, November 2006 [doi>10.1016/j.jcss.2005.12.006]
• 20: Hector Garcia-Molina , Jennifer Widom , Jeffrey D. Ullman, Database System Implementation, Prentice-Hall, Inc., Upper Saddle River, NJ, 1999
• 21: Jeffrey D. Ullman, Principles of Database Systems, W. H. Freeman & Co., New York, NY, 1983
• 22: Daconta, M. Obrst, L., Smith K.: "The semantic web". John Wiley & Sons. (2003).
• 23: Thomas M. Connolly , Carolyn E. Begg, Database Systems: A Practical Approach to Design, Implementation and Management (4th Edition), Pearson Addison Wesley, 2004
• 24: Hector Garcia-Molina , Kenneth Salem, Sagas, Proceedings of the 1987 ACM SIGMOD international conference on Management of data, p.249-259, May 27-29, 1987, San Francisco, California, United States
• 25: Gerhard Weikum , Hans-J. Schek, Multi-level transactions and open nested transactions, Data Engineering, v.14 n.1, p.60-64, March 1991
• 26: Gerhard Weikum , Hans-J. Schek, Concepts and applications of multilevel transactions and open nested transactions, Database transaction models for advanced applications, Morgan Kaufmann Publishers Inc., San Francisco, CA, 1992
• 27: Worah, D., Sheth, A.: "What do advanced transaction models have to offer for workflows?". In Proc. of the International Workshop on Advanced Transaction Models and Architectures (ATMA), 1996.
• 28: Gerhard Weikum, Principles and realization strategies of multilevel transaction management, ACM Transactions on Database Systems (TODS), v.16 n.1, p.132-180, March 1991 [doi>10.1145/103140.103145]
• 29: Schwenkreis, F.: "Aformal approach to syncronize long-lived computations". In Proc. of the 5th Australian Conference on Information Systems, 1994.

INDEX TERMS

Primary Classification:
  H. Information Systems
  H.2 DATABASE MANAGEMENT
      H.2.4 Systems

Additional Classification:
  H. Information Systems
  H.4 INFORMATION SYSTEMS APPLICATIONS
      H.4.1 Office Automation

Keywords:
SQL, databases, internet-based workflows, isolation, workflows