A Scalable Distributed Ontology Repository

In this paper we present a scalable distributed ontology storage system (OntStore), which unlike other ontology repositories is capable of storing and querying the ontologies and the resource descriptions in a distributed manner. It is based on the distributed hash table (DHT) approach emerging in the P2P arena and well known W3C standardized languages. The system decomposes the ontologies into the corresponding triples (subject, predicate, object) and uses the DHT system called Pastry to hash and store the elements. There are no super-peers in the system and both exact-matched and range queries can be routed. The system ensures, that queries do find the resources if the resources are available in the network. It also guaranties, that the number of routing hops for inserting a resource and resolving most queries is logarithmic to the number of nodes in the network.