Supporting dynamic access to virtualized data resources via WSRF-based services

Today grid applications require not only lots of computational power but data at a very large scale too. Although grid computing was initially conceptualized as the technology that focuses on solving compute-intensive problems, this focus has gradually shifted to applications where data is distributed over various locations. Access to these data resources stored in heterogeneous grid storage systems located at geographically distributed virtual organizations in an integrated and uniform way is a challenging problem. The Web Services Resource Framework (WSRF) has recently emerged as the standard for the development and integration of grid services. This paper proposes and presents Gravy4WS, a middleware architecture based on WSRF Web services that enables the dynamic access to virtualized grid data resources. A novel scheduling algorithm called DCE (Delegating-Cluster-Execution based Scheduling) is proposed to improve load balancing of the system. The implementation of Gravy4WS using WSRF libraries and services provided by Globus Toolkit 4 is described together with its performance evaluation.