Optimizing Resource Discovery Technique in the P2P Grid Systems

Distributed discovery service is a main concept in the scalable and dynamic grid environments. In this paper, based on the super-peer technique, we propose a new topology for the grid discovery service. The model is designed in such a way that each super-peer within the cluster has the routing indices (RIs) based on cobweb and uses the hop-count routing index (HRI) to select the best neighbor. Besides, each super-peer includes a cache table, which stores the query and the query results. Furthermore, from the point of view of the response time and the number of submitted messages, we compare the new model with an existing method. An illustrative simulation is also presented to show the efficiency and validation of the new technique.

Proposition of a New Ontology-Based P2P System for Semantic Integration of Heterogeneous Data Sources

Semantic web offers new opportunities to multi-sources integration field, and many approaches like P2P systems are revisited taking into account the new requirements. In this chapter, the authors present their P2P heterogeneous and distributed data integration system. It is a super-peer system, where peers are regrouped by type of data (relational, image, text, etc.) around a super-peer which contains a domain ontology. Peers data sources are exported in a common format in the form of a semantically rich ontology. Schemas reconciliation is done by matching domain and local ontologies by the use of a similarity function whose contribution is based on the direct and indirect semantic neighborhood. Queries are described using ontologies, then routed towards relevant peers thanks to a semantic topology built on top of the existing physical one.