Extending WSLA for Service and Contract Composition

Antonella Longo, Marco Zappatore, Mario Bochicchio


Cloud Services (CSs) nowadays experience constantly improving successes in IT scenarios. Dynamic allocation of network, storage and computational resources, the hiding of visibility of internal IT components, as well as the pay-per-use paradigm are becoming more and more widespread ways to provide and consume services. The complexity of CSs is often due to service chains into which third-party services are aggregated in order to satisfy user requests. This confirms the need of modeling both contracts and corresponding Service Level Agreements (SLAs) referring to services provided to customers. Similarly, time-related variability issues in CSs require run-time performance monitoring and reporting solutions capable of comparing SLAs and feeding requesters with effective resource reservation and allocation policies. A detailed analysis in contracts and SLAs management has revealed a lack of expressivity in SLA specification and a consequent inadequacy in tools for describing and managing SLAs and contract composition. Therefore, we propose an extension of WSLA, a widely known SLA description language. We aim at modeling contracts and SLAs with additional details to support contract owners during service composition and its monitoring. The proposed approach has been adopted to develop and validate a tree-graph-based tool, to simplify SLA and contract composition.


  1. Adell, J., 2012. Neo4jPHP. (Online) Available at: https://github.com/jadell/neo4jphp (Accessed Nov. 2014).
  2. Allen, P., 2006. Service Orientation - Winning Strategies and Best Practices. Cambridge Univ. Press.
  3. Allen, E. & Seaman, C., 2007. Likert Scales and Data Analyses. Quality Progress, pp.64-65.
  4. Andrieux, A. et al., 2007. GFD-R-P.107 Web Services Agreement Specification. Memo. (GRAAP) WG.
  5. Anon., 2007. http://www.panda-project-com/ PANDA: Collaborative Process Automation Support using Service Level Agreements and Intelligent Dynamic Agents in SME Clusters. IST-Panda Reseach Project.
  6. Baker, S. & Dobson, S., 2005. Comparing ServiceOriented and Distributed Object Architectures. In Int. Symp. on Distributed Objects and Applications., 2005.
  7. Bang-Jensen, J. & Gutin, G.Z., 2008. DIgraphs: Theory, Algorithms and Applications. 2nd ed., Springer.
  8. Ben Mabrouk, N. et al., 2009. QoS-aware Service Composition in Dynamic Service Oriented Environments. Middleware 2009 - ACM/IFIP 10th Int. Conf., 2009.
  9. Bochicchio, M.A., Longo, A. & Giacovelli, S., 2013. SARA: a Tool for Service Levels-Aware Contracts. In IFIP/IEEE Int. Symp. on Integrated Network Management, 2013.
  10. Bodenstaff, L., Reichert, M. & Jaeger, M.C., 2008. Monitoring Dependencies for SLAs: the MoDe4SLA Approach. In IEEE Service Computing Conference., 2008.
  11. Boley, H., Tabet, S. & Wagner, G., 2001. Design Rationale of RuleML: A Markup Language for Semantic Web Rules. In SWWS-2001, 2001.
  12. Cardoso, J. et al., 2004. Quality of Service for Workflows and Web Service Processes. Journal of Web Semantics, 1, pp.281-308.
  13. Christensen, E., Curbera, F., Meredith, G. & Weerawarana, S., 2001. http://www.w3.org/TR/wsdl Web Service Description Language (WSDL) 1.1. W3C Note.
  14. Cortellessa, V. & Grassi, V., 2007. A Modeling Approach to Analyze the Impact of Error Propagation on Reliability of Component-based Systems., 2007.
  15. Dijkman, R.M., Dumas, M. & Ouyang, C., 2008. Semantics and Analysis of Business Process Models in BPMN. Inform. and Software Tech., 50(12), pp.1281- 94.
  16. IBM Corp., 2006. IBM Web Services Toolkit (WSTK). (Online) (2.3 (discontinued)) Available at: http://www.alphaworks.ibm.com/tech/webservicestool kit.
  17. Keller, A. & Ludwig, H., 2002. RC22456 The WSLA Framework: Specifying and Monitoring Service Level Agreements. Technical Paper. IBM Research.
  18. Lamanna, D., Skene, J. & Emmerich, W., 2003. SLAng: a Language for Defining Service Level Agreements. FTCDS 2003, 2003.
  19. Lodi, G., Panzieri, F., Rossi, D. & Turrini, E., 2007. SLA-Driven Clustering of QoS-Aware Application Servers. IEEE Trans. on Software Eng., 33(3), pp.186- 97.
  20. Ludwig, H., Dan, A., Kearney, R. & Heights, Y., 2004. Cremona: an Architecture and Library for Creation and Monitoring of WS Agreements. Res. Rep. IBM.
  21. Neo Technology, Inc., 2014. Neo4j. (Online) (2.1.6) Available at: http://www.neo4j.org/ (Nov. 2014).
  22. OASIS, 2014. OASIS -Advancing open standards for the information society. (Online) Available at: https://www.oasis-open.org/ (Accessed November 2014).
  23. Paschke, A., 2008. Knowledge Representation Concepts for Automated SLA Management. Decision Support Systems, 46(1), pp.187-205.
  24. Piccinelli, G., 1999. HPL-1999-84 Service Provision and Composition in Virtual Business Comm.. Tech. Rep.
  25. Pivotal SW, Inc., 2014. Spring Data Neo4J. (Online) http://projects.spring.io/spring-data-neo4j (Nov. 2014).
  26. Saeedi, K., et al., 2010. Extending BPMN for Supporting Customer-Facing Service Quality Requirements. In IEEE Int. Conf. on Web Services., 2010.
  27. Stamou, K., Kantere, V. & Morin, J.H., 2013.10. SLA Data Management Criteria. In IEEE Big Data., 2013.10.
  28. Stamou, K., Kantere, V. & Morin, J.H., 2013.6. SLA Template Filtering: a Faceted Approach. In 4th Int. Conf. on Cloud Computing, GRIDs and Virtualization., 2013.6.
  29. Telemanagement (TM) Forum, 2008. SLA Handbook Solution Suite v2.0.
  30. Ul Haq, I. & Schikuta, E., 2010. Aggregation Patterns of Service Level Agreements. FIT'10, 2010.
  31. Ward, C., et al., 2002. A Generic SLA Semantic Model for the Execution Management of e-Business Outsourcing Contracts. In 3rd Int. Conf. on e-Commerce and Web Technologies., 2002.
  32. Xiang, F., Tevfik, B. & Jianwen, S., 2004. Analysis of Interacting BPEL Web Services. In WWW 7804, 2004.
  33. Zheng, Z. & Lyu, M.R., 2010. Collaborative Reliability Prediction of Service-Oriented Systems. In 10th ICSE. Cape Town, South Africa, 2010. ACM.

Paper Citation

in Harvard Style

Longo A., Zappatore M. and Bochicchio M. (2015). Extending WSLA for Service and Contract Composition . In Proceedings of the 17th International Conference on Enterprise Information Systems - Volume 3: ICEIS, ISBN 978-989-758-098-7, pages 307-315. DOI: 10.5220/0005401503070315

in Bibtex Style

author={Antonella Longo and Marco Zappatore and Mario Bochicchio},
title={Extending WSLA for Service and Contract Composition},
booktitle={Proceedings of the 17th International Conference on Enterprise Information Systems - Volume 3: ICEIS,},

in EndNote Style

JO - Proceedings of the 17th International Conference on Enterprise Information Systems - Volume 3: ICEIS,
TI - Extending WSLA for Service and Contract Composition
SN - 978-989-758-098-7
AU - Longo A.
AU - Zappatore M.
AU - Bochicchio M.
PY - 2015
SP - 307
EP - 315
DO - 10.5220/0005401503070315