Study And Application Of Synchro Data Replica Between Gird Nodes

The development of grid technology provides a new solution to data sharing in theWAN, it is a real sense of resource sharing. When users have access to the sharedresources on long-distance node, there will be some access delay because the grid isbased on Internet. In order to improve the performance of grid system, Replicatechnology comes into being. In the grid system, establishing multiple copies of thesame data file can reduce access delay and meet users’ demand. The introduction ofReplica technology can enhance the performance of the grid system, and also brings arange of issues, among them how to keep the consistency of replica is one of the keyproblems. As there are many Replica files, so when upgrading of the consistency, weneed to know the location of the Replica files in the network, which is the problem ofReplica location.In order to solve the two problems, after analyzing the solution to problem ofReplica location, we present a expandable Replica location model in which theinformation of Replica location is stored in some distributed nodes in the grid. In orderto solve the problem of inconsistency caused by Replica upgrading, we adoptversioning mechanism for Replica consistency, each logical file and its respectiveReplica are assigned with their own versioning numbers. All the versioning numberswill control the consistency among replicas. We also propose that each logical file isassigned with a replica consistency service (RCS), the RCS combined with versioningcontrol mechanism can keep the consistency of replicas. In order to avoid thebottleneck caused by the large number of replica consistency service instances, wehave distributed those instances into some grid nodes.Finally, this paper analyzes and designs the architectural structure of Hunanmobile company expert information grid, replica catalog and the replica consistencyaccording to the idiographic requirements of expert information grid.