The two-double mechanism of grid GIS resource discovery based on P2P

This paper researches on how to realize fast spatial resource discovery in distributed, heterogeneous Grid GIS environment. The characteristic of spatial data as multi-resource, huge volume, heterogeneous formats and time relativity decides that resource discovery in Grid environment is a very complex and exigent problem. Combining the central control with distributed management technology, this paper supposes a two-double resource discovery mechanism with both distributed resource catalog and dynamic hash table, which is just fit to the spatial data access characteristics that distributed in wide area but concentrated in local area. This method overcomes the single node bottleneck by setting up the dynamic service sections among middle layer metadata servers, and utilizes the improved DHT technology to route queries in high efficiency. With the new method, people multi-attribute resource discovery could be supported that not limited by the special keyword as P2P does. It is helpful to solve the spatial information discovery problem in complex environment, which could also enhance the extendibility and credibility of system.