Resource Load Based Stochastic DAGs Scheduling Mechanism for Grid Environment

The dynamic feature is one of the most important differences between Grid and traditional heterogeneous distributed systems, thus the most significant challenge for task scheduling in Grid environment is how to relieve the resource performance dynamism effectively. However, the existing schedule algorithms usually suppose that computation or communication times are deterministic and static, thus they will lead to bad performance in the practical Grid environment. To address this problem, a mechanism which is used to estimate the probability distribution of task execution time based on resource load is proposed. And then a Resource Load based Stochastic DAGs Scheduling algorithm for Grid environments is introduced. The simulation results show that our mechanism can achieve a significant improvement in several metrics (such as normalized real schedule length) and can relieve the influence brought by the dynamic nature of Grid effectively.