ppBLAST: A Computational Service over Peer-to-Peer Network for BLAST

BLAST is a popular toolset for protein and nucleotide sequence comparison. Recent estimates show that these databases of protein and nucleotide sequences are set to grow exponentially and as a result local BLAST searches on single PCs cannot satisfy recent data processing requirements. Traditional approaches for the parallelisation of BLAST are focused on utilising clusters. However, scaling clusters to adapt potential growing BLAST requests will significantly increase the cost and complexities of maintenance and administration. This paper introduces ppBLAST, a BLAST service utilising the free computing resources in the peer-to-peer overlay on the Internet. ppBLAST uses several peer-to-peer technologies such as DAST, DHT and BitTorrent-like distribution and layered design. In this paper, the feasibility of ppBLAST is validated through a small-scale deployment. The performance of ppBLAST is evaluated; we show that the execution time of a BLAST job can be considerably shortened if the scale of the supporting peer-to-peer overlay is large enough.