Directing requests and acquiring knowledge in a large-scale Grid system

This paper proposes two resource discovery mechanisms (the Upgrading and the Re-routing one) in a large-scale Grid system, in which the categorization of resources plays a crucial role. Through a simple matchmaking framework, each resource is identified as being part of a certain category, using its technical specifications (i.e. disk, and memory). Each Virtual Organization (VO) acquires only partial/limited knowledge of the availability of resources controlled by other VOs in the system. The goal is to discover a suitable resource for a request, and then effectively direct this request to the specific VO that controls locally the appropriate resource. During the satisfaction of requests, the VOs are supported and enhanced by the proposed resource discovery mechanisms in order to gain better knowledge of the Grid resource availability. As the creation and satisfaction of requests progresses, the VOs manage to acquire an adequate knowledge of the Grid resources, enhancing the overall system´s well-function. Finally, this paper presents the performance evaluation for both of the proposed resource discovery mechanisms by providing a number of simulation tests.