Abstract

Large document collections are increasingly available over the network. In order for users to access these collections, information retrieval systems must provide coordinated, concurrent, and distributed access. Since even unified information retrieval (IR) systems place heavy demands on system resources, it is unclear how performance will be affected as user demand increases and the distributed IR systems grow in size. In this paper, we present the implementation of a simulator and a prototype system, and the design for experiments to study the performance of distributed IR systems. The prototype distributed information retrieval system is based on Inquery, an existing, unified IR system. We have implemented a flexible simulation model to serve as a platform for analyzing performance issues given a wide variety of system parameters and configurations. We validate the accuracy of our simulation model using the prototype. We present a series of experiments that are designed to measure system utilization and identify bottlenecks. We vary numerous system parameters, such as the number of users and text collections, number of terms per query, response time, and system load to generalize our results for other distributed IR systems.

Citations