The Key Issues Of Grid Portal Research Based On OGSA

Grid computing is a new technology emerging in recent years. The grid concept stems from the mid-1990s and it comes from electric network. 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, storage resources, data resources, information resources, software resources, communication resources, knowledge and expert resources and so on.Since the grid concept was proposed, the grid technology has developed rapidly, and grid architecture has played an important role in the development of the grid technology. Grid architecture focuses on how to build a grid and it is the backbone and core technology of the grid. It's important to realize that only on the basis of a reasonable grid architecture can we design a suitable grid and make full use of it. With the development of the Internet and under the influence of industry leaders like IBM, the Global Grid Forum, after taking into account the impact of Web technology and absorbing the Web services technology, proposed the Open Grid Services Architecture (OGSA). The most prominent feature of the OGSA is focusing on"service,"and it has proposed a service-oriented model. The OGSA combines Grid service with Web service, and the Grid architecture in general is taking the path of standardization.The emergence of the grid makes possible a wide range of applications, such as scientific research that requires a large amount of calculation, large data-processing and even the commercial operation, which can now be done more quickly and more satisfactorily. But the underlying structure of these applications is more complex and difficult to manage, so all kinds of services and portals have been developed. It is under such circumstances that grid portal has come into existence. Grid portal is one of the most important parts of a grid. It is the bridge that links users and the grid, through which users can visit various grid resources and complete different operations. Grid portal provides a uniform access interface based on web browser, reducing the complexity of using the grid and thus pushing forward the grid development.Firstly this paper sets up a grid portal development environment on the basis of the OGSA. Then based on this development environment, it studies and realizes the development of two models of Hibernate-based and service-oriented simple grid portal. It goes further to study the data transfer mechanism based on GridFTP under the grid environment and realizes data transmission using GridFTP agreement based on Java CoG. Finally, by combining the advantages of FTP and GridFTP, this paper has proposed a complex transfer protocol, ERFTP, in view of the characteristic of the Educational Resource Grid. This is where the innovation of this paper lies.On the basis of previous researches, the concrete research work and innovation of the paper can be described as follows:(1)The paper studies the architecture, the function characteristic of the grid as well as the related technologies of grid portal, and in particular the OGSA. Having made a detailed comparison of the different grid portal development kits, it selects the appropriate grid portal development tools to build a grid portal environment.(2)The paper introduces the Hibernate technology in detail and explores the technology of developing the Grid Portal using Hibernate. It facilitates the operation of the database, through the introduction of Hibernate technology in the Portal development. With the development of a practical Educational Resource Grid, it fully shows that the use of the Hibernate technology has greatly improved the efficiency of the software development projects.(3)Based on the Open Grid Services Architecture, the paper elaborates on how to write and deploy a Grid Service in detail. Meanwhile, it explains how to combine the Grid Service with the grid portal, which will provide great convenience for the users in their use and management of the grid resources.(4)The paper introduces the data transfer mechanism based on Java CoG under the grid environment and realizes data transmission using GridFTP agreement. Combining the advantages of FTP and GridFTP, this paper has proposed a composite transfer protocol ERFTP. This part of the research has been applied in the replica management module of the National Natural Science Foundation of China project"The Architecture and Service Theory of Educational Resource Grid Research Based on Internet", and the effect turns out to be very good. This is the key innovation presented by this paper.