Workflow Execution Plan Generation in the Cloud Computing Environment Based on an Improved List Scheduling Algorithm

Focusing on the higher ratio of processor utilization and lower execution cost of a scientific workflow in the cloud environment, an improved list scheduling algorithm was proposed in this paper. This algorithm combines the ideas of both list scheduling and task duplication. According to the priority of the tasks, choosing reasonable parent task to replicate can help reduce the overhead between tasks. To properly insert tasks during processor idling time can help to increase the processor utilization. Based on these, we proposed an improved strategy to generate the workflow execution plan, called EPGILS. Experiment results show that the algorithm is feasible and efficient in reducing the task completion time and improving the utilization ratio of the processor.