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Integrated Research in GRID Computing- P2

Integrated Research in GRID Computing- P2:The deployment process for adaptive Grid applications does not finish when the application is started. Several activities have to be performed while the application is active, and actually the deployment system must rely on at least one permanent process or daemon. | 4 INTEGRATED RESEARCH IN GRID COMPUTING sources cannot change often and significantly otherwise they might violate the mappings to the mediated schema. The rise in availability of web-based data sources has led to new challenges in data integration systems in order to obtain decentralized wide-scale sharing of semantically-related data. Recently several works on data management in peer-to-peer P2P systems are pursuing this approach 4 7 13 14 15 . All these systems focus on an integration approach that excludes a global schema each peer represents an autonomous information system and data integration is achieved by establishing mappings among the various peers. To the best of our knowledge there are only few works designed to provide schema-integration in Grids. The most notable ones are Hyper 8 and GDMS 6 . Both systems are based on the same approach that we have used ourselves building data integration services by extending the reference implementation of OGSA-DAI. However the Grid Data Mediation Service GDMS uses a wrapper mediator approach based on a global schema. GDMS presents heterogeneous distributed data sources as one logical virtual data source in the form of an OGSA-DAI service. For its part Hyper is a framework that integrates relational data in P2P systems built on Grid infrastructures. As in other P2P integration systems the integration is achieved without using any hierarchical structure for establishing mappings among the autonomous peers. That framework uses a simple relational language for expressing both the schemas and the mappings. By comparison our integration model follows like Hyper an approach not based on a hierarchical structure. However differently from Hyper it focuses on XML data sources and is based on schema-mappings that associate paths in different schemas. 3. XMAP A Decentralized XML Data Integration Framework The primary design goal the XMAP framework is to develop a decentralized network of semantically related schemas that .