Scheduling and management of virtual resources in grid sites : the site resource scheduler

This paper presents a new approach to resource management and scheduling in computational grids, in order to simplify the vision users have from grid resources and their management. Scheduling decisions are moved to the site where resources are hosted, allowing quick response to changes in load and resource availability. Users do not need to be aware of the resources they use and are instead supplied with "virtual resources" representing the amount of computational power available to them in the site. This approach results in new challenges, like the management of two-level scheduling schema and the need to define a site capacity measure, but simplifies and optimizes scheduling in grids. In this paper we present details of this approach - called Site Resource Scheduler (SRS) - as well as some issues regarding its simulated performance and its deployment in a site. We show that the main advantage of this approach is an overall reduction in the execution time of tasks in most scenarios.