Sharing checkpoints to improve turnaround time in desktop grid computing

In this paper, we present a checkpoint sharing methodology to improve turnaround time of applications run over desktop grid environments. In fact, volatility of desktop grid nodes reduces the efficiency of such environments when a fast turnaround time is sought, since a task might get stalled if its assigned machine remains unavailable for a somewhat long period of time (long at the scale of the computation). The rationale behind our approach is to permit checkpoint reuse, so that when a computation is forced to move from one node to another, it can be restarted from an intermediary point provided by the last saved checkpoint. We study the effects of sharing checkpoints in application turnaround time simulating three scheduling algorithms based on first come first served: FCFS, FCFS-AT and FCFS-TR. The targeted environment consists of institutional desktop grids. Our results show that sharing checkpoints is particularly effective in volatile environments, yielding performance improvement up to three times relatively to schemes based on private checkpoints. Furthermore, for non-volatile environments, a simple timeout strategy produces good results.