SOFTWARE—PRACTICE AND EXPERIENCE Softw. Pract. Exper. 2005; 35:345–359 Published online 21 December 2004 in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/spe.639 Scalability evaluation of the Yima streaming media architecture Roger Zimmermann ∗,† , Cyrus Shahabi, Kun Fu and Shu-Yuen Didi Yao Integrated Media Systems Center and Department of Computer Science, University of Southern California, Los Angeles, CA 90089–2561, U.S.A. SUMMARY Over the last decade research has been pursued on all aspects of streaming media. While many theoretical results have been reported in the literature, few performance results of large-scale systems have been published. In this report we specifically explore the scalability aspects of our Yima streaming media architecture in an end-to-end test environment. With Yima, it was our goal to design and implement an architecture that would scale in performance from small to large systems. Some of the design features include (1) a multi-node cluster architecture based on commodity hardware and custom software, (2) media type independence (support ranges from 500 Kb s -1 MPEG-4 to 45 Mb s -1 HDTV, at both variable and constant bitrates), (3) fine-grained online scale up/down capabilities, and (4) a client-controlled rate smoothing protocol. We briefly discuss the design and implementation of these capabilities of Yima and then thoroughly evaluate its scalability through several sets of experiments. Our results show that Yima scales linearly (within the range of our test parameters) as a function of the cluster size and also as a function of available resources such as network bandwidth and CPU performance. Copyright c  2004 John Wiley & Sons, Ltd. KEY WORDS: streaming media; continuous media; multimedia servers 1. INTRODUCTION We report on the implementation and evaluation of a scalable real-time streaming media architecture called Yima ‡ , which enables applications such as news-on-demand, distance learning, e-commerce, corporate training, and scientific visualization on a large scale. A growing number of applications store, maintain, and retrieve large volumes of real-time data, where the data are required to be available online. We denote these data types collectively as ‘continuous media’, or CM for short. ∗ Correspondence to: Roger Zimmermann, Integrated Media Systems Center and Department of Computer Science, University of Southern California, Los Angeles, CA 90089–2561, U.S.A. † E-mail: rzimmerm@imsc.usc.edu ‡ Yima in ancient Iranian religion, is the first man, the progenitor of the human race, and son of the sun. Contract/grant sponsor: National Science Foundation; contract/grant numbers: EEC-9529152 (IMSC ERC) and IIS-0082826 Copyright c  2004 John Wiley & Sons, Ltd. Received 10 June 2003 Revised 21 June 2004 Accepted 21 June 2004