The Quest for Bandwidth Estimation Techniques for large-scale Distributed Systems

In recent years the research community has developed many techniques to estimate the end-to-end available bandwidth of an Internet path. This important metric has been proposed for use in several distributed systems and, more recently, has even been considered to improve the congestion control mechanism of TCP. Thus, it has been suggested that some existing estimation techniques could be used for this purpose. However, existing tools were not designed for large-scale deployments and were mostly validated in controlled settings, considering only one measurement running at a time. In this paper, we argue that current tools, while offering good estimates when used alone, might not work in large-scale systems where several estimations severely interfere with each other. We analyze the properties of the measurement paradigms employed today and discuss their functioning, study their overhead and analyze their interference. Our testbed results show that current techniques are insufficient as they are. Finally, we will discuss and propose some principles that should be taken into account for including available bandwidth measurements in large-scale distributed systems. 1

Research on network anycast

Anycast is defined as a service in IPv6, which provides stateless best effort delivery of an anycast datagram to at least one, and preferably only one host. It is a topic of increasing interest. This paper is an attempt to gather and report on the work done on anycast. There are two main categories at present: network-layer anycast and application-layer anycast. Both involve anycast architectures, routing algorithms, metrics, applications, etc. We also present an efficient algorithm for application-layer anycast, and point out possible research directions based on our research. <br /

Performance-directed site selection system of AADMLSS

The popularity of the World Wide Web (WWW) in providing a vast array of information has drawn a large number of users in the past few years. The dramatic increase in the number of Internet users, however, has brought undesirable impacts on users, such as long response time and service unavailability. The utilization of multiple servers can be used to reduce adverse impacts. The challenge is to identify a good resource site to allocate to the user given a group of servers from which to select. In this project, a performance-directed site selection system was developed for a web-based application called AADMLSS (African American Distributed Multiple Learning Styles System). Four different sets of experiments were conducted in this study. In order to evaluate the effectiveness of the test system, two other server selection methods, Load-based and Random-based methods, were implemented for comparative purposes. The experiments were also run during daytime and nighttime to see the impact of network load on the response time. Experimental results indicate that the performance-directed site selection system outperforms the Load-based and Random-based methods consistently. The response time is typically high during daytime and low during nighttime, indicating that the network load has an impact on the response time delivered. The results also show that server performance contributes to the overall response time, and network performance is the more dominating factor in determining a good resource site for the user

Evaluation of a Novel Two-Step Server Selection Metric

Choosing the best-performing server for a particular client from a group of replicated proxies is a difficult task. We offer a novel, two-step technique for server selection that chooses a small subset of five servers, and isolates testing to that subset for ten days. We present an empirical evaluation of both our method and previously proposed metrics based on traces to 193 commercial proxies. We show that our technique performs better than any of the other metrics we studied — often one to two seconds better for a one-megabyte file — while requiring considerably less work over time. Metrics such as round-trip time and tests using small files usually select servers that are two to three times worse than the best server. Network-layer metrics such as minimizing router and autonomous system count poorly predict which server provides the best performance. These metrics often select servers with transfer times four to six times that of the best-performing serve

Anycast services and its applications

Anycast in next generation Internet Protocol is a hot topic in the research of computer networks. It has promising potentials and also many challenges, such as architecture, routing, Quality-of-Service, anycast in ad hoc networks, application-layer anycast, etc. In this thesis, we tackle some important topics among them. The thesis at first presents an introduction about anycast, followed by the related work. Then, as our major contributions, a number of challenging issues are addressed in the following chapters. We tackled the anycast routing problem by proposing a requirement based probing algorithm at application layer for anycast routing. Compared with the existing periodical based probing routing algorithm, the proposed routing algorithm improves the performance in terms of delay. We addressed the reliable service problem by the design of a twin server model for the anycast servers, providing a transparent and reliable service for all anycast queries. We addressed the load balance problem of anycast servers by proposing new job deviation strategies, to provide a similar Quality-of-Service to all clients of anycast servers. We applied the mesh routing methodology in the anycast routing in ad hoc networking environment, which provides a reliable routing service and uses much less network resources. We combined the anycast protocol and the multicast protocol to provide a bidirectional service, and applied the service to Web-based database applications, achieving a better query efficiency and data synchronization. Finally, we proposed a new Internet based service, minicast, as the combination of the anycast and multicast protocols. Such a service has potential applications in information retrieval, parallel computing, cache queries, etc. We show that the minicast service consumes less network resources while providing the same services. The last chapter of the thesis presents the conclusions and discusses the future work

Evaluation of a Novel Two-Step Server Selection Metric

Choosing the best-performing server for a particular client from a group of replicated proxies is a difficult task. We offer a novel, two-step technique for server selection that chooses a small subset of five servers, and isolates testing to that subset for ten days. We present an empirical evaluation of both our method and previously proposed metrics based on traces to 193 commercial proxies. We show that our technique performs better than any of the other metrics we studied — often one to two seconds better for a one-megabyte file — while requiring considerably less work over time. Metrics such as round-trip time and tests using small files usually select servers that are two to three times worse than the best server. Network-layer metrics such as minimizing router and autonomous system count poorly predict which server provides the best performance. These metrics often select servers with transfer times four to six times that of the best-performing serve

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