Distributed Server Selection and Admission Control in Replicated Web Systems

This paper addresses the problems of admission control and server selection in a system consisting of several geographically replicated web servers and several access points. We propose a fully distributed solution in which every access point continuously monitors the availability of all server side resources, using a mixture of active and passive measurements. Based on those measures, each access point autonomously applies its decisions to the requests it receives. Admission control is performed prioritizing requests belonging to already admitted sessions, in order to maximize the chance of successfully terminating ongoing sessions. Furthermore, session information is taken into account when performing a probabilistic request redirection and server choice, in order to improve load balancing and mitigate flash crowd effects. Extensive simulations, performed in compliance with industry standards, show that our method exhibits a stable behavior during overloads and improves service quality in terms of both reduced response time and higher successful session termination.

[1]  Akshat Verma,et al.  On admission control for profit maximization of networked service providers , 2003, WWW '03.

[2]  Philip S. Yu,et al.  The state of the art in locally distributed Web-server systems , 2002, CSUR.

[3]  Weijia Jia,et al.  Distributed admission control for anycast flows , 2004, IEEE Transactions on Parallel and Distributed Systems.

[4]  Ying Lu,et al.  Improved Prediction for Web Server Delay Control , 2004 .

[5]  Daniel A. Menascé,et al.  TPC-W: A Benchmark for E-Commerce , 2002, IEEE Internet Comput..

[6]  Ludmila Cherkasova,et al.  Session-Based Admission Control: A Mechanism for Peak Load Management of Commercial Web Sites , 2002, IEEE Trans. Computers.

[7]  Erich M. Nahum,et al.  A method for transparent admission control and request scheduling in e-commerce web sites , 2004, WWW '04.

[8]  G. Bochmann,et al.  A Probabilistic Approach for Admission Control to Web Servers , 2004 .

[9]  John S. Heidemann,et al.  Flash crowd mitigation via adaptive admission control based on application-level observations , 2005, TOIT.

[10]  Eelco Herder,et al.  Off the beaten tracks: exploring three aspects of web navigation , 2006, WWW '06.

[11]  H.B. Hashim,et al.  An active anycast RTT-based server selection technique , 2005, 2005 13th IEEE International Conference on Networks Jointly held with the 2005 IEEE 7th Malaysia International Conf on Communic.

[12]  Sang Hyuk Son,et al.  Feedback Control Architecture and Design Methodology for Service Delay Guarantees in Web Servers , 2006, IEEE Transactions on Parallel and Distributed Systems.

[13]  Raphael Rom,et al.  Application-aware admission control and scheduling in Web servers , 2002, Proceedings.Twenty-First Annual Joint Conference of the IEEE Computer and Communications Societies.

[14]  Weijia Jia,et al.  Distributed server selection with imprecise state for replicated server group , 2004, 7th International Symposium on Parallel Architectures, Algorithms and Networks, 2004. Proceedings..