The distributed spanning-tree based service discovery in grid environment

With the dynamic and heterogeneous characteristics of resources in grid environment, efficient service discovery becomes a challenging issue. In this paper, we propose a service discovery approach based on the distributed spanning-tree architecture. According to this architecture, we arrange the grid resources in such a hierarchical way as IS layer, Institution layer, Organization layer and Domain layer in turn. Any member at the same layer is equivalent. Only IS layer and Institution layer have real resource entities while other layers over them are overlays to cluster the resource information onto their own Delegation Nodes (DN). These DNs have the Resource Index and can locate the query route. Hence, query message traffic is sharply decreased depending on the DN's locating of query routes. Every Institution in grid owns a global unique ID according to the coding mechanism. Based on this, the parallel searching process can be synchronously implemented among peer nodes, which improves the efficiency dramatically. Caching and Collaboration Units techniques are adopted to increase the efficiency of service discovery. The DN can be replaced by the new elected one when it fails which ensures the survivability of the system. Performance evaluation shows that our approach achieves a good efficiency, scalability, survivability and adaptability.