A Copy Of The Education Resources In The Grid Management Strategy Research

With the popularization of computer technology and the development of digital campus,primary and middle schools of our country accumulate a large number of educational resources,including Excellent course, video tutorials, experimental reports and so on. However, differentschools manages these resources on their own way. Resource sharing among schools is not high,which forms a separated information island. Education resource grid is proposed in order toefficiently share educational resources. It views different schools as virtual organizations andmanage educational resources based on the grid, which provides an efficient platform for theeducation resource sharing and avoids the waste of resources and software redevelopment.As a kind of data grid, replica management technology also plays a very important role ineducation resource grid. On the one hand, the existence of replicas efficiently improvesavailability of resources and avoids the phenomenon that the resources are not available owing tothe nodes’leaving. On the other hand, replica technology makes the request for a certain file notconcentrate on the same node, which balances the network load to some extent. Thirdly, replicatechnology improves the efficiency of data access, the setting up of replica can reduce thedistance of data transmission. Unique characteristics of educational resources grid suggestresearching replica management technology has very important significance in educationalresource grid environment. According to the replica management problems existed in theeducation resource grid, the paper mainly do the following works.First, the paper studies educational resource grid environment and replica managementtechnology and elaborates the significance of educational resource grid replica managementstrategy. The paper introduces the concept,features,system structure and research status of gridand data grid and so on, analyzes unique characteristics and system structure of educationalresource grid and clearly describes the research environment. Then, the paper elaborates theconcepts and features of replica management and introduces the various functional modulesincluded in the copy management in detail.Second, the paper proposes a replica creation strategy based on the node load. Afterspecificly analyzing features of model of educational resources grid, the paper proposes a replicasetting strategy based on node load. According to the situation where the request node is, thestrategy is divided into replica request in domains and replica request among domains. In thesame domain, replica creation is carried out based on the nodes whose load is small to balancethe nodes load. However, for the quest among domains, replica is created on the managementnodes to reduce the price of remote transmission of replica. The experiments suggest that, in education resource grid model environment, the strategy can improve the average execution timeof jobs.Third, the paper proposes a replica selection strategy using fuzzy multi-attributedecision-making. The strategy utilizes availability, security, response time and cost as selectioncriteria between different replicas. In order to evaluate the attributes more convenience, we usetriangular fuzzy numbers to describe the attributes. The selection criteria(availability, security,response time and cost) are heterogeneous and cannot be aggregated with each other for theselection, furthermore, the criteria may contradict one against other. In order to select the replicawith fairness and satisfy the users, the paper considers the problem as a multi-attribute decisionmaking problem,which provides a new solution for replica selection.Finally, an example toillustrate the feasibility of the strategy .At last, the paper deeply studies the OptorSim simulator and improves the typical algorithmof the simulator. In order to verify the validation of replica creation strategy, the paper choosesOptorsim as experimental tools to deeply study. The architecture of OptorSim, main frame,theclass and several classical replica management algorithm are introduced. Through analyzing thedefect of LRU and LFU of OptorSim in realization, LRU and LFU are improved. Throughcomparing with the original algorithm, the experimental results suggest the performance of theimproved algorithm is raised.