Research On Task Scheduling Algorithms On Grid

The rapid developing network makes it possible to integrate the geographically distributed and heterogeneous computing resources into tremendous Grid. So the tasks scheduling in Grid has become a quite important problem. And the research of schedule algorithms, which directly related to the speed, quality and other factors of the Grid, plays a decisive role in the research of computing Grid.Min-min algorithm, a classics algorithm in heuristic algorithm, which always completes the shortest total completion time task first, has the characteristic of simple and shortest completion time. So it catches a lot of close attentions in the field of studying for tasks scheduling algorithms in Grid.But if we take the bandwidth in considering, we will find that every task has a different demand for it. Some tasks need nothing, while others require comparatively higher bandwidth. And it may exit such situations that some ordinary tasks occupy the resources with high bandwidth, while other high bandwidth required tasks cannot get the resources they need. In result of the problem mentioned just now, the Min-min algorithm already can not satisfy the need for scheduling. So we should consider new algorithms that take the tasks' demands for bandwidth in account. Therefore, HE Xiaoshan and other researchers brought forward the QoS Guided Min-min algorithm based on Min-min algorithm. Since considering the request for QoS, which means the quality of service, this algorithm applies better than Min-min algorithm in the dynamic Grid environment.According to the QoS Guided Min-mim algorithm, this paper focuses on the following researches:Discusses the meaning for task scheduling algorithms researching. Then introduces the research status for task scheduling objects, algorithms, and simulators of task scheduling algorithms.Expands the concept of QoS, and takes the particularities of the resources and tasks in considering. We use resource sign and task sign to indicate different kinds of resources and tasks. All the tasks are scheduled according to their task signs. And all these changes are based on QoS Guided Min-min algorithm.The GridSim toolkit is modified according to the modified QoS Guided Min-min algorithm. And we simulate Min-min algorithm, QoS Guided Min-min algorithm and modified QoS Guided Min-min algorithm on NetBeans and...