Adaptive file transfer and policy study in cloud computing

File transfer is a critical component in the application of cloud computing, moreover, efficient and flexible file transfer with reliability has an important role in guaranteeing a good quality of service for users. Thus this paper brings forward a creative thinking of a novel structure for adaptive file transfer based on strategies and multiprotocol, and proposes the idea of guaranteeing the quality of service for each file transfer by ensuring the quality of service of network under suitable level, and on those bases, the algorithm for adaptive file transfer, or the AFTA, is proposed. Experiments indicate that the algorithm based on the policy library, knowledge library, info library and quality of service of the network can transfer a file with more efficiency, flexibility and reliability according to file´s attributes and other facts.