Research On Data Transfer Model And Strategy Based On Resource Grid

The grid is a hot topic in the study of the current high-performance computing, is called the next generation computer network's foundation. The Grid originally makes use of computers in different places and combines them through Internet to form a super virtual computer to help realize the comprehensive sharing of computing resources, data resources, software resources, communication resources and so on. The development of grid technology take the data transmission technology as a foundation, the nearly all business processes need to carry on reliable, fast access to the sharing data. Data transmission technology is the important technology of grid, is the key technology to realize resources transmission in the multi-replica coexisting grid environment. The scale of grid resources is huge, the position is scattered, the therefore it requires a robust transmission mechanism.As a result of the grid technology in the huge superiority of resources sharing, its application scope will certainly expanding unceasingly along with its own development and maturity, and gradually penetrates into the field of education. Education resources grid is one kind of data grid, has its characteristics such as distributed, isomerism, autonomy, dynamic and hierarchical and so on. Combination the resources distributed characteristics of education resources grid, has analyzed data transmission demand in education resources grid, proposed a new data transmission model. Replica is the key technology of data grid. It creates local copies of remote data, reduces network latency and bandwidth consumption, and simultaneously forms a way of multi-replica coexisting grid resources sharing which provides opportunity to resolve transfer problems.The purpose of this paper was to improve resource access efficiency of the resources grid, and study on data transmission model and the correlation strategies based on GridFTP protocol and Replica technology. The main works were that:(1)Introduced the concept and characteristics of grid, discussed the three kinds of grid architecture and Globus Toolkit projects. Depth studied of Web Service technology and Open Grid Service Architecture, and the related knowledge of Grid services. Compared the similarities and differences between Web Service and Grid Service, and the experiment showed can use the Web Service technology to increase the functions of grid service.(2)Analyzed the data transmission demand in the grid environment, introduced the grid transfer protocol GridFTP, focus on its support for a variety of transmission types and transmission modes. Studied the transmission performance of GridFTP, whether in or not under the grid service, based on the GridFTP data transfer service function provided by Globus Toolkit 4.0, and the experiment explained that the grid service provided by OGSA would help to improve the transmission performance of GridFTP.(3)Cleared about Replica technology, summarized the key technologies of Replica, and analyzed the Replica Location and Selection algorithms, which involved in this paper. Proposed Multi-replica Partial file Transfer model MPT, and gave the definition of the model and the method to select the best replica quantity. The multi-level replica location strategy MPT-RL based on locality was designed to carry on the search and location of replicas, defined the task allocation algorithm of the model, and some modules of the model were designed and implemented.(4)Research of data transmission strategies in the resources grid, including: Replica Found and Location strategy, the strategy to enhance the transmission performance and so on. Against the shortage of GridFTP crossing heterogeneous platform, proposed the improvement mechanisms for transmission performance based on the grid service.Finally, the paper summarized the research and proposed some relevant aspects of this topic to be further studied.