| Grid makes full use of all kinds of available resource which scattered in different geography position to form a virtual super computer, which prepare high-performance computing power, expensive experiment equipment and other rare resource for users. It also provides convenient and inexpensive infrastructure construction to scientific research field makes research work more effciency. But, all these depend on a perfect resource management system and a high-performance task scheduling algorithm. Resource managemnet and task scheduling are integrated components of grid computing, especially the research of task scheduling algorithm, playing a very important role in all the research of grid computing.There are many algorithms resolving this problem presently, but majority of them only concerned one or a few QoS constraints, resolve the task sechduling problem under special appointed constrains, which have a obviously limitation, can not resolve the task scheduling problem in a real grid computing circumstance. The thesis analyse the problem of multiple QoS constrained task scheduling in grid environment, grid QoS is graded, then a grid task scheduling model and a concerned scheduling algrithm is proposed base on the different QoS level affected.The main research and innovation of this thesis is included in the following areas:Firstly, this thesis introduced several conceptions such as the definition, purpose, and system architecture of resource management, then expatiate the importance of the task schedule in the study of grid computing. Thoroughly analyse the target and execution flow of task scheduling, and compare several traditional static and dynamic scheduling algorithms. In addition, also presents some task scheduling algrothm base on economic model.Secondly, Base on the research of the grid task scheduling algorithm and classification of QoS constrains, a novel grading scheduling model was established for resolve the scheduling problem of multiple QoS constrains. Thirdly, this thesis define the resources which being able to satisfy all QoS constrains of the task as valid resources. Tasks and resources are graded according to the matrix for valid resources. A grade-constrained task scheduling algorithm is proposed base on grade of tasks and modification of traditional scheduling algorithm.Finally, the GridSim Toolkit was selected for test the performance of the gird task scheduling algorithm. Then the toolkit is modified according to the grade-constrained task scheduling algorithm. A series of experiments was designed to study the effect caused by different parameters, then compared the novel algorithm to the Min-min algorithm, as the results show, the algorithm turned out to be more adapting to the multiple QoS constrained task scheduling due to the less Makespan.This thesis is supported by National Natural Science Foundation (60402028, 60773211), Program for New Century Excellent Talents in University (08-0806) and the Topping Youth Foundation of Hubei Province (2008CDB335). |
