Geographic load balancing for scalable distributed Web systems
- 1 August 2000
- conference paper
- Published by Institute of Electrical and Electronics Engineers (IEEE)
Abstract
Users of highly popular Web sites may experience long delays when accessing information. Upgrading content site infrastructure from a single node to a locally distributed Web cluster composed by multiple server nodes provides a limited relief, because the cluster wide-area connectivity may become the bottleneck. A better solution is to distribute Web clusters over the Internet by placing content nodes in strategic locations. A geographically distributed architecture where the Domain Name System (DNS) servers evaluate network proximity and users are served from the closest cluster reduces network impact on response time. On the other hand, serving closest requests only may cause un-balanced servers and may increase system impact on response time. To achieve a scalable Web system, we propose to integrate DNS proximity scheduling with an HTTP request redirection mechanism that any Web server can activate. We demonstrate through simulation experiments that this further dispatching mechanism augments the percentage of requests with guaranteed response time, thereby enhancing the Quality of Service of geographically distributed Web sites. However, HTTP request redirection should be used selectively because the additional round-trip increases network impact on latency time experienced by users. As a further contribution, this paper proposes and compares various mechanisms to limit reassignments with no negative consequences on load balancing.Keywords
This publication has 12 references indexed in Scilit:
- Redirection algorithms for load sharing in distributed Web-server systemsPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2003
- Server selection using dynamic path characterization in wide-area networksPublished by Institute of Electrical and Electronics Engineers (IEEE) ,2002
- Scalable Web server clustering technologiesIEEE Network, 2000
- Workload characterization of a Web proxy in a cable modem environmentACM SIGMETRICS Performance Evaluation Review, 1999
- Dynamic load balancing on Web-server systemsIEEE Internet Computing, 1999
- Summary of WWW characterizationsComputer Networks and ISDN Systems, 1998
- Network Dispatcher: a connection router for scalable Internet servicesComputer Networks and ISDN Systems, 1998
- End-to-end routing behavior in the InternetIEEE/ACM Transactions on Networking, 1997
- Modeling the performance of HTTP over several transport protocolsIEEE/ACM Transactions on Networking, 1997
- Wide-area Internet traffic patterns and characteristicsIEEE Network, 1997