Scheduling independent tasks sharing large data distributed with BitTorrent

Data-centric applications are still a challenging issue for large scale distributed computing systems. The emergence of new protocols and software for collaborative content distribution over Internet offers a new opportunity for efficient and fast delivery of high volume of data. In a previous paper, we have investigated BitTorrent as a protocol for data diffusion in the context of computational desktop grid. We showed that BitTorrent is efficient for large file transfers, scalable when the number of nodes increases but suffers from a high overhead when transmitting small files. This paper investigates two approach to overcome these limitations. First, we propose a performance model to select the best of FTP and BitTorrent protocols according to the size of the file to distribute and the number of receiver nodes. Next we propose enhancement of the BitTorrent protocol which provides more predictable communication patterns. We design a model for communication performance and evaluate BitTorrent-aware versions BT-MinMin, BT-MaxMin and BT-Sufferage scheduling heuristics against a synthetic parameter-sweep application.