Imprecise calendars: an approach to scheduling computational grids

We describe imprecise calendars, a way to organize and schedule clusters of nodes in a computation grid. Imprecise calendars permit the easy and efficient sharing of resources between different clusters of computers that are part of a computational grid. In addition, they can be used to provide specific time reservations for applications. We describe the algorithms and policies for manipulation of imprecise calendars. We also include a series of simulation studies that compare our approach to previous batch scheduling systems for both a single cluster and collection of clusters up to over 3000 nodes.