Complex Topology-based Grid Resource Discovery Mechanism

Grid is considered as next generation network, which aims to achieve resource sharing and cooperating work in environment of internet. However,the key of resource sharing and cooperating work is effective resource discovery, and it is basic establishment of implementing high-level applications in grid. Grid resource discovery remains one of the most complex problems in grid, which is worth deeply research in theory and practice.This paper proposes a grid resource discovery mechanism based on compound topology, which provides flexible and efficient resource discovery service for grid resource sharing.Firstly, this paper proposes that the essence of resource discovery is to find information of requried resource in aggregateand of resource information and the key of resource discovery mechanism lies in how to organise and manage resource information in order to support resource discovery. Through analysing and researching resource discovery mechanism in the whole space of resource information space, we find that only in structural and ordered resource information space,reality of efficient resource discovery is possible. So we adopt distributed fashion to organise resource information and form a structural and ordered resource information space in logicAt the same time we let information node know the whole knowledge of resource information distribution,make resource discovery requests orderly transmitted among information nodes.Secondly, we propose classified resources description methord, information node based on resource description and distribution, and policy of resource register based on information organization structure.Compound topology brings btter extensibility and reliability to GRIMBOT in large scale. Compound DHT system makes information node process the whole knowledge of resource information distributing,so resource discovery requests purposefully query and routes among layers,and improves efficiency.Thirdly, we research GRIMBOT in structural level and function level, implement information structure,and construct index overlay network and information server center,register mechanism and resource discovery service flexibly and efficiently. This paper proposes two classes of flexible implementation mechanisms to improve performance of GRIMBOT.The first class solves the problems of accessing bottleneck and single point failure,and improves reliability such as scalable entry of domain, circularity clockwise failure checking method about master RDMS, failure ckecking method about assistant RDMS and RDMS failure resume mechanism. We find most resource discovery requests route only in this resource management domain,and thesecond class improves efficiency such as assistting route with information node of multi-domain overlap >. multi- point register strategy in user register and beforehand intelligently dispensing resource discovery request in user agent.This paper analyses the performance of GRIMBOT by means of qualitative analysis > quantitative analysis and simulation/The results indicate that GRIMBOT has better absolute ability and efficiency in resource discovery.Finally,through analysing characteristic of satellitic information resources, we suggest a new attribute of geography area to organise satellitic resources,and build a prototype system about satellitic information resources based on compound topology.