A P2P Resource Discovery System Based on a Forest of Trees

The convergence of the Grid and Peer-to-Peer (P2P) worlds has led to many solutions that try to efficiently solve the problem of resource discovery on Grids. Some of these solutions are extensions of P2P DHT-based networks. We believe that these systems are not flexible enough in the case the data present in the network is very dynamic, i.e. the data values change very frequently over time. This a very common case for some kind of data in typical Grid systems, like CPU loads, queue occupation, etc. In this paper we present a variation of a previous work based on a tree-shaped P2P overlay network. The system uses Routing Indexes to efficiently route queries and update messages in the presence of highly variable data. The new system is based on a twolevel hierarchical network topology, where tree topologies must be only maintained at the lower level of the hierarchy. The main aim of this new organization is to achieve a simpler maintenance of the overall P2P graph topology. This is reached at the cost of some imprecision in the routing indexes built at the upper level of the graph hierarchy.