Grid resource discovery based on a routing-transferring model

The Grid technology emerges with the need of resource sharing and cooperation in wide area. Compared with the traditional single computer system, effective resource locating in Grid is difficult because of huge amount and wide-area distribution of dynamical resources. In this paper, we propose a Routing-Transferring resource discovery model, which includes three basic roles: the resource requester, the resource router and the resource provider. The provider sends its resource information to a router, which maintains this information in routing tables. When a router receives a resource request from a requester, it checks routing tables to choose a route for it and transfer it to another router or provider. We give the formalization of this model and analyze the complexity of the SD-RT (Shortest Distance Routing-Transferring) algorithm. The analysis shows that the resource discovery time depends on topology (the longest path in the graph) and distribution of resources. When topology and distribution axe definite, the SD-RT algorithm can find a resource in the shortest time. Our experiments also show that when topology is definite, the performance is determined by resource distribution, which includes two important factors: resource frequency and resource location. The testing result shows that high frequency and even location of resources can reduce the resource discovery time significantly.