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SBAC-PAD 2002. GloVE: A Distributed Environment for Low Cost Scalable VoD Systems. Leonardo Bidese de Pinho Edison Ishikawa * Claudio Luis de Amorim COPPE Systems Engineering Program Federal University of Rio de Janeiro, RJ, Brazil * Systems Engineering Department
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SBAC-PAD 2002 GloVE: A Distributed Environment for Low Cost Scalable VoD Systems Leonardo Bidese de Pinho Edison Ishikawa* Claudio Luis de Amorim COPPE Systems Engineering Program Federal University of Rio de Janeiro, RJ, Brazil *Systems Engineering Department Military Institute of Engineering, RJ, Brazil Supported by
Summary SBAC-PAD 2002 • Introduction • Cooperative Video Cache (CVC) • Global Video Environment (GloVE) • Performance Analysis of GloVE • Conclusions and Future Work
Summary SBAC-PAD 2002 • Introduction • Cooperative Video Cache (CVC) • Global Video Environment (GloVE) • Performance Analysis of GloVE • Conclusions and Future Work
Video On Demand (VoD) SBAC-PAD 2002 • Video delivery service • Choose a video at any time • Fast playback start • Huge bandwidth consumption • Basic components • Client-side buffer
VoD Scalability SBAC-PAD 2002 • Conventional Systems • Client/Server Model • Unicast Streams • One stream One receiver • How to add scalability to video delivery? • Reuse content delivered by the server • One stream Multiple receivers • Proposed techniques • Batching [Dan et al., 1996] • Chaining [Sheu et al., 1997] • Patching [Hua et al., 1998]
Summary SBAC-PAD 2002 • Introduction • Cooperative Video Cache (CVC) • Global Video Environment (GloVE) • Performance Analysis of GloVE • Conclusions and Future Work
A New Strategy for VoD SBAC-PAD 2002 • CVC [Ishikawa and Amorim, 2001] • Local buffers as components of a distributed cooperative cache • Prior source of video • Aggregated bandwidth • New request • Increase CVC • Increase CVC hit • Decrease server’s load • Allow inexpensive servers
Patching x Chaining x CVC SBAC-PAD 2002
Original Proposal SBAC-PAD 2002 • GoF as access unit • Variable size structure • Complex to handle • Multiple formats • Server with multicast support
Extended Approach SBAC-PAD 2002 • Block as access unit • Allows any kind of continuous media • Support for unicast servers • Multicast streams among clients • Aggregation ofBatching • Streams provided are synchronized with playback • Problem: “Prefetch Effect” • Solution: Batching on prefetching clients
Summary SBAC-PAD 2002 • Introduction • Cooperative Video Cache (CVC) • Global Video Environment (GloVE) • Performance Analysis of GloVE • Conclusions and Future Work
Main Concepts SBAC-PAD 2002 • P2P system with centralized metadata • Clients request video to manager • Manager monitors content of local buffers • Video streams among clients
System Components SBAC-PAD 2002 • Video Server • RIO Server • Network • IP Multicast • CVC Client • CVC Manager
CVC Client (CVCC) SBAC-PAD 2002
CVC Manager (CVCM) SBAC-PAD 2002 New Stream Derivation + Patch Batching
Summary SBAC-PAD 2002 • Introduction • Cooperative Video Cache (CVC) • Global Video Environment (GloVE) • Performance Analysis of GloVE • Conclusions and Future Work
Environment & Workload SBAC-PAD 2002 • Experimental Environment • 6 PIII 650 MHz | 512 MB | SCSI | Redhat Linux 2.2.14 • 1 Server+Manager | 1 Workload+Monitor | 4 Clients • Switch 3COM with multicast support • Workload Definition • Poisson Process • One MPEG-1 NTSC-SIF video • Simulated decoder/player • Parameters
Analysis of Results SBAC-PAD 2002 • Conventional Server • 56 MPEG-1 logical channels • Manager Modes • Metrics • Occupation Rate (OR) • Percentage of occupation of server’s logical channels • Latency (LT) • Average time between the client request and the playback start
Occupation Rate SBAC-PAD 2002 Prefetch Effect
Latency SBAC-PAD 2002
10% 3 6 10 Impact of Local Buffer Size SBAC-PAD 2002
Summary SBAC-PAD 2002 • Introduction • Cooperative Video Cache (CVC) • Global Video Environment (GloVE) • Performance Analysis of GloVE • Conclusions and Future Work
Conclusions SBAC-PAD 2002 • GloVE • Scalable CVC-based VoD system • Independent of continuous media format • Support for unicast servers • Batching concepts • Main advantages • Reduction near to 90 % of OR under arrival rate > 3 clients/min and 16 MB buffers • One channel to deliver a highly popular video with arrival rate > 30 clients/min and 4 MB buffers
Future Work SBAC-PAD 2002 • Hide the increase on latency • Complementary experiments • Multiple videos • Various formats (Mpeg-4 / DivX) • ZipF-like distribution • Impact of VCR operations • Next version of GloVE • Multi platform • Network without multicast
Additional Information SBAC-PAD 2002 • Laboratory of Parallel Computation Website: www.cos.ufrj.br/~lcp E-mail: lcp@cos.ufrj.br