Client-side Selection Of Replicated Web Services: An Empirical Assessment

Replicating web services over physically distributed servers can offer client applications a number of QoS benefits, including higher availability and reduced response time. However, selecting the "best" service replica to invoke at the client-side is not a trivial task, as this requires taking into account factors such as local and external network conditions, and the servers' current workload. This paper presents an empirical assessment of five representative client-side service selection policies for accessing replicated web services. The assessment measured the response time obtained with each of the five policies, at two different client configurations, when accessing a world-wide replicated service with four replicas located in three continents. The assessment's results were analyzed both quantitatively and qualitatively. In essence, the results show that, in addition to the QoS levels provided by the external network and the remote servers, characteristics of the local client environment can have a significant impact on the performance of some of the policies investigated. In this regard, the paper presents a set of guidelines to help application developers in identifying a server selection policy that best suits a particular service replication scenario. © 2007 Elsevier Inc. All rights reserved.81813461363Amini, L., Shaikh, A., Schulzrinne, H., Modeling redirection in geographically diverse server sets (2003) Proceedings of the 12th International World Wide Web Conference (WWW 2003), pp. 472-481. , ACM Press, Budapest, HungaryApache, 2006. AXIS Version 1.4. Available at http://ws.apache.org/axis/ (accessed 28.02.07)Cauldwell, P., Chawla, R., Chopra, V., (2001) Professional XML Web Services, , Wrox Press, Birminghan, USACosta, L.A.G., Pires, P.F., Mattoso, M., Automatic composition of web services with contingency plans (2004) Proceedings of the IEEE International Conference on Web Services (ICWS'04), , IEEE Computer Society Press, Washington, DC, USADamani, O., Chung, Y., Kintala, C., Wan, Y., ONE-IP: techniques for hosting a service on a cluster of machines (1997) Proceedings of the 6th International World Wide Web Conference (WWW'97), pp. 1019-1027. , Elsevier Science Publishers, Ltd., California, USADykes, S.G., Robbins, K.A., Jeffery, C.L., Empirical evaluation of client-side server selection algorithms (2000) Proceedings of the 19th Annual Joint Conference of the IEEE Computer and Communications Societies (INFOCOM 2000), 3, pp. 1361-1370. , Tel Aviv, IsraelHanna, M.K., Natajaran, N., Levine, N.B., November 2001. Evaluation of a novel two-step server selection metric. In: Proceedings of the 9th IEEE International Conference on Network Protocols (ICNP'01). California, USA, p. 290Hu, J., Guo, C., Wang, H., Zou, P., Quality driven web services selection (2005) Proceedings of the IEEE International Conference on e-Business Engineering (ICEBE'04), pp. 681-688. , IEEE Computer Society PressKeidl, M., Kemper, A., A framework for context-aware adaptable web services (2004) Lecture Notes in Computer Science, 2992, pp. 826-829. , Proceedings of the 9th International Conference on Extending Database Technology (EDBT 2004), SpringerLiu, Y., Ngu, A.H.H., Zeng, L., QoS computation and policing in dynamic web service selection (2004) Proceedings of the 13th International World Wide Web Conference (WWW'04), pp. 66-73. , ACM Press, New York, NY, USAMakris, C., Panagis, Y., Sakkopoulos, E., Tsakalidis, A., Efficient and adaptive discovery techniques of web services handling large data sets (2006) Journal of Systems and Software, 79 (4), pp. 480-495Menascé, D., QoS issues in web services (2002) IEEE Internet Computing, 6 (2), pp. 72-75Mendonça, N.C., Silva, J.A.F., An empirical evaluation of client-side server selection policies for accessing replicated web services (2005) Proceedings of the 20th Annual ACM Symposium on Applied Computing (SAC 2005), Special Track on Web Technologies and Applications, pp. 1704-1708. , ACM Press, Santa Fé, New Mexico, USAMicrosoft, 2006. NET Framework Version 3.0. Available at http://www.microsoft.com/net/ (accessed 28.02.07)OASIS, 2002. Universal Description, Discovery e Integration (UDDI) Version 2.0. Available at http://www.oasis-open.org/committees/uddi-spec/doc/tcspecs.htm#uddiv2 (accessed 28.02.07)Ouzzani, M., Bouguettaya, A., Efficient access to web services (2004) IEEE Internet Computing, 8 (2), pp. 34-44Padovitz, A., Krishnaswamy, S., Loke, S.W., July 2003. Towards efficient and smart selection of web services. In: Proceedings of the Second International Joint Conference on Autonomous Agents and Multi-agent Systems (AAMAS 2003), Workshop on Web Services and Agent-based Engineering (WSABE). Melbourne, AustraliaPapazoglou, M.P., Georgakopoulos, D., Service-oriented computing: introduction (2003) Communications of the ACM, 46 (10), pp. 25-28Ran, S., A model for web services discovery with QoS (2003) ACM SIGecom Exchanges, 4 (1), pp. 1-10Rodriguez, P., Biersack, E.W., Dynamic parallel access to replicated content in the internet (2002) IEEE/ACM Transactions on Networking, 10 (4), pp. 455-465Salas, J., Pérez-Sorrosal, F., Patiño-Martínez, M., Jiménez-Peris, R., WS-Replication: a framework for highly available web services (2006) Proceedings of the Fifteenth International World Wide Web Conference (WWW 2006), pp. 357-366. , ACM Press, Edinburgh, ScotlandSayal, M., Breitbart, Y., Scheuermann, P., Vingralek, R., Selection algorithms for replicated web servers (1998) ACM SIGMETRICS Performance Evaluation Review, 26 (3), pp. 44-50Serhani, M.A., Dssouli, R., Hafid, A., Sahraoui, H., A QoS broker based architecture for efficient web services selection (2005) Proceedings of the IEEE International Conference on Web Services (ICWS'05), pp. 113-120. , IEEE Computer Society PressSUN, 2006. Java Web Services Developer Pack (JWSDP) Version 2.0. Available at http://java.sun.com/webservices/downloads/webservicespack.html (accessed 28.02.07)Tian, M., Gramm, A., Ritter, H., Schiller, J., Efficient selection and monitoring of QoS-aware web services with the WS-QoS Framework (2004) Proceedings of the IEEE/WIC/ACM International Conference on Web Intelligence (WI'04), pp. 152-158. , IEEE Computer Society PressW3C, 2001. Web Services Definition Language (WSDL) Version 1.1, W3C Note 15. Available at http://www.w3.org/TR/wsdl (accessed 28.02.07)W3C, 2003. Simple Object Access Protocol (SOAP) Version 1.2, W3C Note 08. Available at http://www.w3.org/TR/SOAP/ (accessed 28.02.07)Yoshikawa, C., Chun, B., Eastham, P., Vahdat, A., Anderson, T., Culler, D., 1997. Using Smart Clients to Build Scalable Services. In: Proceedings of the USENIX Annual Technical Conference. Anaheim, California, USAYu, T., Lin, K.-J., A broker-based framework for QoS-aware web service composition (2005) Proceedings of the IEEE International Conference on E-Technology, E-Commerce and E-Service (EEE'05), pp. 22-29. , IEEE Computer Society PressYu, T., Lin, K.-J., Service selection algorithms for web services with end-to-end QoS constraints (2005) Journal of Information Systems and E-Business Management, 3 (2), pp. 103-126Zhou, C., Chia, L.-T., Lee, B.-S., QoS-aware and federated enhancement for UDDI (2004) International Journal of Web Services Research, 1 (2), pp. 58-85Zhuge, H., Liu, J., Flexible retrieval of web services (2004) Journal of Systems and Software, 70 (1-2), pp. 107-11