Research On The Mechanism Of Resource Replication In The Grid

Grid is a development direction of distributed and parallel processing technology.The goal of Grid is to realize share of heterogenous resources that locate all over the world,and replication management is the core technology and soul of Grid.Replication can reduce access latency,improve data locality,and increase robustness,scalability and performance,or balance the loads for distributed applications.Excellent resources replication management strategies are important to improve the Qos in grids. Resouces replication management in the grid can reduce the communication cost on solitary service site.It also has good effect on reducing the bandwidth consumption caused by frequent remote access and balancing the load of global grid.This paper goes into the researching status of this question and points out meagerness of applying various resource replication management techniques in using now into Grid.Then,this paper analyzes the supermarket model in Grid resource replicaton management,and make out the characteristic and reason for introducing the supermarket model in the problem.Based on previous research,the major research works and initiative points in this article are:Firstly, this thesis discusses the rationality of using supermarket method and agent technology to manager grid resource replication, and make out the need and feasibility of introducing the supermarket method,It uses operation of principle of the supermarket in actual life to manage the resouce replicattion in grid and has both thrust and pulling force in the resouce replicaton.Secondly,proposing a data location strategy based on ant system.Through adjusting position and quantity of the data replication dynamically,using the program of optimizing to reduce the accessing time and cost,which can adapt to the dynamic traint,integrate the existent distributed system,and fit the inherent scalability.Thirdly, proposing a improved Fast Upload method.The resource dynamic replication strategy must solve the three key points ,that is, which,when, and where the replicas should be created.Finally, proposing the file replacement strategy for Grid cache based on economic model.The goal is considering the resource provider's and consumer's behalf,and they can gain most interests,so that it can offer the motivation to attract them attending the Grid.Therefore,to make the resouce provider have enough motives to continue offering its resouce-sharing,and to make the users have more little cost in order to obtain more excellent service.Using against Vickrey auction protocol in which the agreement submits a tender to the price secretly enable each bidder to provide their true price,thus make the resouce provider and user reach win-win and make the whole performace of the grid can have been improved.Because in the research of grid resource replication management,it is unnecessary to use real systems to evaluate the performance and accuracy of the algorithms,usually emulators are used to handle with it.Several grid emulators are illustrated in this paper,and GridSim,a grid modeling and emulation toolkit,is introduced in details.Finally,with the help of GridSim Toolkit,the emulation of grid resource management algorithms with QoS requirements is realized.The experiment results show that the algorithm present in this paper is feasible. It improves the performance of grid on a whole.