Stretching Scheduling Algorithm for Multiple DAGs Tasks in Heterogeneous System

In this paper, aiming at a high miss deadline ratio in the large-scale task scheduling of heterogeneous parallel computing environment, the Arrived-Heterogeneous Earliest Finish Time (A-HEFT) algorithm based on the valid main path was proposed. This algorithm not only ensures all subtasks effectively processed within the time limit, but performs better in scheduling random arrival Directed Acyclic Graph (DAG) and the resource utilization among them during the execution period. Firstly, we proposed a new model of tasks produced by the same data source with a certain order based on the traditional model of DAG. Then, change the calculation of the upward rank of tasks in Heterogeneous Earliest Finish Time (HEFT) according to the task attribute of DAG, and get the execution priority from upward rank of sub-tasks. Finally, execute stretching scheduling based on idle time on the main path. Compared with Limited Preemptive Earliest Deadline First (LPEDF) algorithm and HEFT algorithm, the results of our work shows that A-HEFT algorithm performs better in processor utilization and success rate of task scheduling in heterogeneous system scheduling.