Research On Task Scheduling In Ad Hoc Grid Computing

With the rapid development of the mobile technologies and the mobile devices widely used, a new grid architecture--Ad Hoc grid emerges. Ad Hoc grid is a type of grid with the aim of harnessing unused computational resources inside or across organizations, which allows a group of mobile devices to accomplish a mission, often in a hostile environment.The Ad Hoc grid is a spontaneous organization of cooperating heterogeneous nodes into a logical community without a fixed infrastructure and with only minimal administrative requirements.The mobile devices in the Ad Hoc grid not only use the resources in the grid,but also contribute their own computing and storage resources.As most of the Ad Hoc grid resources work in the mobile-wireless environment and mobile devices have their own disadvantages, such as limited energy, mobility, security, etc, which bring many problems in grid task scheduling. Currently, there are few research on trust mechanism algorithm while people mostly focus on reducing energy consuming and the minimum completion time.This thesis proposes that in the process of task scheduling in the Ad Hoc grid, how to combine the grid task scheduling with trust mechanism, and also consider the task completion time and energy consuming,to achieve the goal of improving the grid security and efficiency.The leading research and innovation of this thesis are as follows:Firstly, We propose the Ad Hoc grid architecture according to characteristic of the mobile devices, and combine the trust mechanism with the Ad Hoc grid task scheduling. We design the node data structure about the direct trust value and recommend trust value which are suitable for the Ad Hoc grid environment.Secondly, According to the characteristic of Ad Hoc grid resources and the QoS requirement of the task, we propose the cost function after considering the energy consuming and the task completion time, with the aim of improving the lifetime of the Ad Hoc grid.Thirdly, We propose the trust mechanism based Ad Hoc grid task scheduling algorithm. We firstly choose the task-resource with the minimum cost function under the requirement of the trust mechanism, in other words, we select the resource nodes which have the minimum completion time and energy consuming. The goal of the algorithm is to improve the security and efficiency of the grid.Finally, This thesis simulates the TATSA scheduling algorithm and compares the results with the Min-Min algorithm in the rate of the successful tasks and the minimum completion time.The experiment proves the high performance of the trust mechanism based task scheduling algorithm which we proposed in the thesis.This thesis is supported by National Natural Science Foundation of China (No:60970064),New Century Excellent Talents in university(No:NCET-08-0806), Open Fund of the State Key Laboratory of Software Development Enviroment(SKLSDE-2011KF-01), Fok Ying-Tong Education Foundation for Young Teachers in Higher Education Institutions of China(No:121067),NSF of Wuhan Municipality(No:201010621207).