Research Of The Transfer Model Based On Multi-Agent In Grid Environment

Data grid meets the demand for data-intensive tasks with good data sharing and collaboration capabilities, such as high-energy physics, climate modeling and so on. However, because of the dynamic and complex grid environment, node failures and unexpected changes in network occur frequently. So the speed and stability of grid data transfer can't be guaranteed, and it has become the"bottleneck"that restricts grid applications.With introduction of Multi-Agent technology, it brings the virtue of saving network bandwidth, realizing load and uninstall, increasing application's robustness, and affording platform independence and so on, which can solves problems in the transmission process primely. It brings forward challenge with introduction of Multi-Agent technology, the most important points including Multi-Agent Coalition formation and negotiation.The purpose of this paper was to increase the data transfer speed and stability in grid environment. The Globus Toolkit middleware and Simulator OptorSim were used and the research focused on the combination of Multi-Agent technology with data transfer. The main works were that:(1) Data transfer and Multi-Agent technology were analyzed in data grid: this paper analyzes and compares current transfer protocols/mechanism, as well as the mechianism of improving transfer efficiency in grid; and finally, deeply studys Multi-Agent technology's architecture and application in grid for Agent;(2)Transfer model (Multi-Agent Transfer Model)MATM based on Multi-Agent is proposed: This paper defines the model's topology, architecture and composition elements; and finally, deeply studys Multi-Agent coalition formation and negotiation mechinaism for MATM;(3) Multi-Agent coalition formation tactic is designed: this paper defines Multi-Agent coalition structure and the problem of descripting coalition formation using mathematic methods; besides these, combined with linear programming, this paper designs Multi-Agent coalition formation tactic in detail;(4)Construted negotiation mechanism: firstly, this paper investigates negotiation mechanism, and analyzes selection problem for negotiation opportunity using mathematic theory; and then, defines agent design and negotiation evaluation mechianism for negotiation; finally, designs the negotiation arithmetic for negotiation mechianism;(5) Tested and analyzed Model MATM: Based on the simulator OptorSim, the experiments testing model's performance were done, as well as the performance analysis.Theoretical analysis and experimental results showed that the MATM model had effectively improved the speed and stability of data transfer, especially for bulk data transfer.