Research On Scheduling Strategy Of Key Multi-resource In Grid Workflow Environments

Nowadays, the establishment of e-government and informative contact among most districts in our country are merely at the foundational stage of the release of information. Isolated system enclosure block the share of informative resources, in addition, the disintegrated of date formats and the re-existed date in different systems separate the whole normal business, which should be integrate together, into different parts. These problems, interfering the governmental co-ordination, the work efficiency of supervision and the improvement of public service, restrain the development of the Chinese e-government.The emergence of grid technology provides an excellent opportunity for solving these problems, as the core of grid is the integration of information and resources. Due to the workflow technology makes the process automatic and integrated, and improves work efficiency, spontaneously let us associate with the integration of grid and workflow technology. Therefore, the concept of grid-workflow comes out.Nevertheless, most of the existing grid-workflow system at present is designed for the demands of workflow multiplexing, based on the peculiar grid system of high-energy physics and bioinformatics. Not only are they heavy on workflow modeling, but also rarely considering task scheduling as the simplified user group, consequently there is no priority on relative scheduling strategy. For e-government grid-workflow system which has more complicated user group, resources limiting, the tasks submitted by the user group need some mechanisms to make sure that they must be finished within a reasonable period of time.This paper begins with grid, introduces grid-resource management and task scheduling, and indicates that the strategy of task scheduling is the key factor influencing the efficiency of grid system. On this basis, connecting with traditional workflow, it points out the necessity of studying grid-workflow, thus makes a brief introduction of grid-workflow and e-government model based on the grid-workflow. Secondly, after comparing and analyzing several modeling means of workflow, it adopts Petri Net to build grid-workflow net for the average case of administrative procedures for examination and approval in e-government. Through this case, it helps to analyze the function of order scheduling that has the minimum loss of work time in key department, which is based on e-government system of grid-workflow. Thirdly, linking up the algorithm of minimum loss of work time in the theory of scheduling, it abstracts mathematical model, and improves the algorithm under the practical conditions. On a single key-resource task scheduling matters, it establishes a dynamic program dividing the whole due date into several stages, discusses task scheduling algorithm of many key resources and time complexity of relative algorithm, later it utilizes successive approximation to simply the complexity in order to get a dynamic programming algorithm in polynomial time. Last but not the least, it takes advantage of JAVA to realize a emulating system comparing this algorithm and First in First executed algorithm. After many operations, it get a emulated result eventually, which approves that algorithm concerned by this paper helps eliminating the loss of working time.