ONTOGRID - Adopt and influence standards in Semantic Grid and Grid Computing.
Project website:  ONTOGRID 
Principal Investigator: Manolis Koubarakis
Duration: 01/09/2004 - 31/08/2007

The objective of Ontogrid (http://www.ontogrid.eu/) was to support the vision of the Semantic Grid (http://www.semantigrid.org/) by developing technological infrastructure to build metadata-aware middleware and applications, together with guidelines for an adequate use of such enriched applications. The aim is to allow businesses and people to share information, services and computing resources, automating tasks and supporting the rapid formation of virtual organizations which can solve a specific problem and disband just as easily once a solution is found.

In the context of Ontogrid NKUA developed the system Atlas ( http://atlas.di.uoa.gr/). Atlas offers scalable, fault-tolerant and adaptive storage and querying facilities for RDF(S) data. Atlas is built on top of the distributed hash table Bamboo, and works in an open, distributed, dynamic network of nodes. Atlas inherits the desirable features of Bamboo (openness, scalability, fault-tolerance, resistance to high churn rates) and extends Bamboo’s protocols for storing and querying RDF(S) data. Nodes can enter RDF(S) data into the network and pose RQL queries. Two kinds of querying functionality are supported by Atlas: one-time querying and continuous querying (also known as publish-subscribe). Each time a node poses a one-time query, the network nodes cooperate to find RDF(S) data that form the answer to the query. In a continuous querying scenario, a node can subscribe with a continuous query. A continuous query is indexed somewhere in the network and each time matching RDF(S) data is published, nodes cooperate to notify the subscriber.


MaDgIK 2009-2016