Design and implementation of a distributed synchronization scheduler for a multimedia news-on-demand application.

Abstract

The CITR News-On-Demand is a system whose architecture follows the client-server paradigm: a distributed database provides multimedia news articles to users by means of a client application. Due to practical considerations, the synchronization system used in this prototype is a centralized one, in which the client application bears the whole burden of scheduling data retrieval and presentation. While this is simpler to implement, it makes more demands on the client's resources than a distributed system. Furthermore, research into the issue suggests that a distributed system would be more efficient at preventing synchronization errors. This thesis shows how the synchronization system of the News-on-Demand prototype can be re-engineered to make it distributed. It first considers the theoretical concepts behind synchronization systems and provides a framework for doing so simply and in a manner which can be systematically applied to any system. The News-on-Demand prototype is then studied using this framework, and its shortcomings as regard synchronization are discussed. Research at the MCRLab into distributed synchronization systems is also studied with this framework, and it is shown how this research can be applied to the News-on-Demand system. With this, a distributed synchronization system for the CITR project is designed and implemented, which integrates the distributed synchronization concepts into the existing system. The pseudo-code and the data structures of the new system are given and discussed