Grid Interoperability by Multiple Broker Utilization and Meta-Brokering

Summary. As grid technology matures the number of production grids dynamically increases. The management and the optimal utilization of these grid resources cannot be handled by the users themselves. To hide the lower level details of grid access, grid portals have been developed. Unfortunately, today's grid portals are typically tightly coupled to one specic grid environment and do not provide multi-grid support. The P-GRADE Portal is a work ow-oriented multi-grid portal with the main goal to support all stages of grid work ow development and execution processes. One very important aspect of utilizing multiple Grids within one complex scientic work ow is to interact with multiple and potentially dierent grid brokers supported by the dierent Grids. This paper describes how the portal was interfaced to grid brokers to reach resources of dierent grids in an automated way. This way a work ow can be brokered over several grids based on dierent underlying technologies but still providing optimal utilization of resources. To ease the addition and usage of dierent resource brokers, we introduce a meta-brokering concept. With this new grid middleware component portal users can utilize a growing number of Grids for highly computation intensive applications in the future