The Access And Integration Of Grid Database Based On Middleware

As is known as the third wave of the Internet since the mid-1990s and has aroused widespread interest, Grid are being pushed from scientific computing to industrial fields. At the same time, as is a major carrier of information, database plays a very important role in many fields. Database systems are characterized as autonomy, heterogeneity and distributivity, so they cannot provide uniform interfaces to satisfy flexible resource sharing and data access. Grid was defined as flexible, secure, coordinated resource sharing among dynamic collections of individuals, institutions. Therefore, Grid could meet the request of resource sharing. But how to integrate the present databases to Grid environment and to provide uniform interfaces to clients to achieve dynamic and flexible resource sharing becomes an important research direction.In this paper, Grid computing, grid database, middleware, the relevant concepts and techniques are researched. Two kinds of method, which integrated database into the Grid environment, are analyzed. The access and integration of database Grid based on double middleware model system (AIGD-DMMS) is designed in this paper. AIGD-DMMS provides information registration service, which is composed by global registration service and local registration service. And the local registration service is provided by the local registers that are distributed in the information resource nodes. With XML encapsulating database information, client middleware and server middleware are designed in this model. While the main task of client middleware is to deal with the request from the clients, server middleware receives the processed requests from the clients middleware, disassemble and dispose the task, realize the interaction between the middle service and the databases in Grid environment.AIGD-DMMS was designed, tested and realized in this paper. The test example was designed as the nine distributed departments of a company's information in the nine database server, and as another two servers was designed as client middleware and server-side middleware. The model was tested based on Globus platform. Clients could query information through Web browser. The experimental results show that AIGD-DMMS could shield the heterogeneous platforms and systems efficiently, realize the virtual data sources and the flexible sharing of resources with high performance.