Assessing the efficiency of stream reuse techniques in P2P video-on-demand systems

Many works have reported simulated performance benefits of stream reuse techniques such as batching, chaining, and patching to the scalability of VoD systems. However, the relative contribution of such techniques has been rarely evaluated in practical implementations of scalable VoD servers. In this work, we investigated the efficiency of representative stream reuse techniques on the GloVE system, a low-cost scalable VoD platform whose resulting performance depends on the combination of the stream techniques it uses. More specifically, we evaluated performance of the GloVE system on delivering multiple MPEG-1 videos to clients connected to the server through a 100 Mbps Ethernet switch, and arrival rates varying from 6 to 120 clients/min. We present experimental results including startup latency, occupancy of server's channels, and aggregate bandwidth that GloVE demanded for several combinations of stream reuse techniques. Overall, our results reveal that stream reuse techniques in isolation offer limited performance scalability to VoD systems and only balanced combination of batching, chaining, and patching explains the scalable performance of GloVE on delivering highly popular videos with low startup latency while using the smallest number of server's channels.