Sharing a conceptual model of grid resources and services

Grid technologies aim at enabling a coordinated resource-sharing and problem-solving capabilities over local and wide area networks and span locations, orga- nizations, machine architectures and software bound- aries. The heterogeneity of involved resources and the need for interoperability among different grid middle- ware solutions require the sharing of a common in- formation model in order to enable both intra- and inter-grid resources awareness. The research area of computing in High Energy and Nuclear Physics (HENP) is populated by several Grid related projects that mostly rely on basic services provided by the Globus Toolkit (9) and the Condor Project (23). Due to the large adoption of the provided functionalities, interoperability issues are mostly re- lated to what is built on top of these components. For the purpose of enabling HENP Grid middlewares interoperability, the Grid Laboratory Uniform Envi- ronment (GLUE) collaboration (1), a joint US and EU High Energy Physics projects effort, has been set up. One of the main achievements of this collabora- tion has been carried out in the context of the GLUE Schema activity. The main purpose was to define a common resource information model to be used as a base for Grid Information Service (GIS) for both resource discovery and monitoring activities. Start- ing from the Globus MDS schema (12) and the EU DataGrid (EDG) schema, the first implementation- neutral agreement on services (such as batch com- puting and storage managers) and systems (such as