Title :
Adaptive load sharing for clustered digital library servers
Author :
Zhu, Huican ; Yang, Tao ; Zheng, Qi ; Watson, David ; Ibarra, Oscar H. ; Smith, Terence
Author_Institution :
Dept. of Comput. Sci., California Univ., Santa Barbara, CA, USA
Abstract :
This paper investigates load balancing strategies for clustered Alexandria digital library (ADL) servers. The ADL system, which provides on-line information searching and browsing of spatially-referenced materials through the World Wide Web, involves intensive database I/O and heterogeneous CPU activities. Clustering servers can improve the scalability of the ADL system in response to a large number of simultaneous access requests. One difficulty addressed is that clustered workstation nodes may be non-uniform in terms of CPU and I/O speeds. An optimization scheme is proposed in this paper to dynamically monitor the resource availability, use a low-cost communication strategy for updating load information among nodes, and schedule requests based on both I/O and computation load indices. Since the accurate cost estimation for processing database-searching requests is difficult, a sampling and prediction scheme is used to identify the relative efficiency of nodes for satisfying I/O and CPU demands of these requests. A set of experiments using the ADL traces have been conducted to verify the effectiveness of the proposed strategies
Keywords :
Internet; client-server systems; information retrieval; library automation; optimisation; resource allocation; scheduling; ADL system; Alexandria digital library servers; World Wide Web; adaptive load sharing; browsing; clustered digital library servers; clustered workstation nodes; database input output; experiments; heterogeneous CPU; load balancing; online information searching; optimization scheme; resource availability; scalability; Availability; Load management; Monitoring; Processor scheduling; Scalability; Software libraries; Spatial databases; Web server; Web sites; Workstations;
Conference_Titel :
High Performance Distributed Computing, 1998. Proceedings. The Seventh International Symposium on
Conference_Location :
Chicago, IL
Print_ISBN :
0-8186-8579-4
DOI :
10.1109/HPDC.1998.709977