Incremental Scheduling of Mixed Workloads in Multimedia Information Servers

Abstract

In contrast to pure video servers, advanced multimedia applications such as digital libraries or teleteaching exhibit a mixed workload with massive access to conventional, "discrete" data such as text documents, images and indexes as well as requests for "continuous data", like video and audio data. In addition to the service quality guarantees for continuous data requests, quality-conscious applications require that the response time of the discrete data requests stay below some user-tolerance threshold. In this paper, we study the impact of different disk scheduling policies on the service quality for both continuous and discrete data. We provide a framework for describing various policies in terms of few parameters, and we develop a novel policy that is experimentally shown to outperform all other policies. . Currently, Prof. Triantafillou's research focuses in the area of highperformance, intelligent storage systems, including disk drives, disk arrays, and robotic tape/disk libraries, with a special emphasis on multimedia applications. His research activities in the past have focused on multidatabases, distributed file systems, and highly-available distributed databases. Prof. Triantafillou has served in the Program Committees of the ACM MobiDE '99, ACM SIGMOD '99, FODO '98, RIDE '98, and EDBT '98 international conferences and as a reviewer in most relevant international journals.Gerhard Weikum received the diploma degree (where he is leading a research group on database systems. His former affiliations include MCC at Austin, Texas, and ETH Zurich in Switzerland. During his sabbatical in 1997, he was a visiting Senior Researcher in the database research group of Microsoft. Dr. Weikum's research interests include parallel and distributed information systems, transaction processing and workflow management, and database optimization and performance evaluation. Dr. Weikum serves on the editorial boards of ACM Transactions on Database Systems, The VLDB Journal, and the Distributed and Parallel Databases Journal. He has served on numerous program committees of international conferences, he was the program committee co-chair of the 4th International Conference on Parallel and Distributed Information Systems, and he is the program committee co-chair of the 16th IEEE International Conference on Data Engineering. Dr. Weikum has been elected onto the board of trustees of the VLDB Endowment.