Intel Research Seminar

DATE: Thursday, December 5, 2002
TIME: Noon - 1:30 pm
PLACE: Intel Seminar (417 S. Craig Street - 3rd Floor)

Stergios Anastasiadis
Department of Computer Science, Duke University
Durham, NC, USA

Supporting Variable Bit-Rate Streams in a Scalable Continuous Media Server

Dramatic advances in data storage and networking technology have not been sufficient to provide inexpensive wide-scale distribution of streaming video with acceptable quality.

Variable bit-rate encoding is known to generate media streams of considerably smaller size than constant bit-rate encoding of equivalent quality. Hence, the capability to support variable bit-rate streams in content distribution networks has the potential to significantly reduce the cost of media streaming, due to lower requirements for bandwidth and storage space.

In this talk, we describe the design of Exedra, a scalable continuous media server architecture, and its prototype implementation. Innovative resource management policies are examined under a realistic performance evaluation methodology. System throughput is shown to
increase almost linearly with the number of disks, while offering deterministic quality of service guarantees. Fault-tolerant operation can be enabled with minimal additional cost.

High variability in resource requirements can also lead to reduced utilization of system resources. We formulate the need for balancing the disk bandwidth against server buffer utilization as a smoothing optimization problem. A novel optimal algorithm is introduced that can be successfully applied to streams stored across either homogeneous or heterogeneous disks.

Stergios Anastasiadis received MSc and PhD from the Department of Computer Science, University of Toronto in 1996 and 2001 respectively, and Dipl.Eng. from the Department of Computer Engineering and Informatics, University of Patras, Greece in 1994. Since September 2001 he has held a Visiting Assistant Professor position at the Department of Computer Science, Duke University. In his doctoral dissertation, he investigated system design, resource management, and performance evaluation issues in scalable streaming media servers. Previously, he also worked on parallel application scheduling for cluster-based multiprocessors.

For Further Seminar Info:
Contact Kim Kaan, 412-605-1203, or visit

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