A dynamic scheduling algorithm in heterogeneous computing environments

the grid computing system can support execution of computationally intensive parallel and distributed applications. The main characteristics of grid computing system are similar to the heterogeneous computing system, except the fluctuant transfer rate. A dynamic scheduling algorithm, called Dynamic HEFT (DH) algorithm is proposed in this paper to enhance the functions of the original static HEFT (SH) algorithm. Instead of dispatching tasks to physical processors directly, the DH algorithm dispatches tasks to multiple queues. During runtime, the DH algorithm continues to dispatch the scheduled tasks to corresponding physical processor and predicts the transfer rate. Once the difference between two consecutive transfer rates is greater than the threshold value, rescheduling will be performed. The experimental results show that the proposed DH algorithm performs better than the SH algorithm in the system, especially under the grid computing environment, with fluctuant transfer rate and high bandwidth differences.