A novel data replication mechanism in P2P VoD system

With the development of the Internet, high-quality streaming services, including Video-on-Demand, are more popular than ever with the help of P2P technologies. But peer-to-peer (P2P) on-demand streaming systems inevitably suffer from peer churn that is the inherent dynamic characteristic of overlay networks. With frequent peer departure and VCR operations, a large amount of media data cached on peer disks turn off-line and unavailable, which becomes the major reason of heavy server load. And the phenomenon has been proved by the system logs of self-developed P2P based Video-on-Demand platform, called GridCast. To address the above issues, a new proactive data replication mechanism is proposed and implemented into GirdCast. Based on the new mechanism, a peer can proactively replicate data chunks to stable cache servers for future sharing, when it has high possibility to leave the overlay. Two key heuristic algorithms are designed for departure prediction and replicating chunks selection. And the cache servers managements are also described in the submission. Trace driven simulations show that the mechanisms greatly decrease bandwidth load of media source server and improve the availability of chunks highly demanded but poorly provisioned by overlay peers.

► A new proactive data replication mechanism can decrease server load.
► Two key heuristic algorithms are designed for departure prediction and replicating chunks selection.
► Distributed cache servers are managed in load balance mode.