A Local Rarest-Random-Heuristic Data Scheduling for P2P VoD System

Data scheduling is the key issue in peer-to-peer streaming system, especially in peer-to-peer VoD system. This paper mainly focuses on data chunks' priority definition of data scheduling in peer-to-peer VoD system. After carefully studying the meanings of regular rarest first scheduling and random scheduling, a Local-Rarest-Random-Heurist ((LRH)-H-2) scheduling is proposed in order to fully use the resources of strong peers in the system. (LRH)-H-2 fully considers the meanings of rarest first priority and random priority. It brings abundant copies of data chunks in the system by using part of rarest priority and it also avoids the concentrate request in some data chunks which have same rarest priority by adding a random jitter, and then maximize total priority of every scheduling by using heuristic algorithm. Simulation proves that (LRH)-H-2 has achieved a scheduling effect about 30% better than normal rarest first or random scheduling.