Service reliability and performance in grid system with star topology

The paper considers grid computing systems in which the resource management systems (RMS) can divide service tasks into subtasks and send the subtasks to different resources for parallel execution. In order to provide desired level of service reliability the RMS can assign the same subtasks to several independent resources for parallel execution. The service reliability and performance indices are introduced and a fast numerical algorithm for their evaluation for arbitrary subtask distribution in grid with star architecture is presented. This algorithm is based on the universal generating function technique. Illustrative examples are presented.