QoS-based Distributed Query Processing

Abstract

Among the essential functionalities supported by distributed multimedia systems, quality of service (QoS) is of prime interest and requires the involvement of different system components. This unction aims to control and guarantee the level of quality that the system is able to offer to the user. The QoS requirements may concern system performance, the quality of the information, as well as the costs of the service provision. In this paper, we propose a general framework for integrating QoS requirements into a distributed query processing environment. This framework is based on user classes, cost models, utility functions, and policy-based management. We explain how we push QoS requirements and information into the different steps of global query optimization. We present the prototype we have developed as well as the experimentation we have conducted to validate our approach.