Experience integrating a General Information System API in LCG Job Management and Monitoring Services

In a Grid environment, both middleware services and applications require information on system resources.Unfortunately, different implementations of Grid Information Services use different data models, and define different access protocols.We have detected the necessity of a high level API that makes the applications independent of the underlying technology of the service, and shields them from possible changes in its interface.In this article, we present the design of such an API, which can interact with several existing implementations of the Information Service.It is flexible enough to adapt to future changes.We have also implemented a prototype of the API, which can query the Globus MDS and R-GMA, while presenting a single interface to the user.