The Research And Implementation On Key Technology Of Database Sharing In Grid

Data grid is an effective technology to uniformly access and manage distributed heterogeneous massive data in Internet. Since database has been an important tool for data management at present, how to integrate all kinds of database resources into data grid in order to provide comprehensive data management demands is a new problem to be solved urgently. Database grid is a data grid setting mainly about database resources, which focuses on key technologies of uniform storage, access and management database resources. Now, the researches on database grid is at the underway and developing stage, the correlative implement technologies are immature, and there are no whole standards and specifications, so our research and practice work in this project is worth of exploring.Our project researches in detail a few of famous database grid systems or data grid Systems that relate to database, analyses and summarizes key technologies of database grid, thus we put forward a suit of effective uniform access and management mechanism about database in grid. According to these work, we design and develop database grid prototype system called GridDaEn-DAI.It adopts Java mechanism and integrates database resources in Internet, provides uniform logical data views and data access service for grid user at different places. This system mainly adopts multi-domain server mechanism and server-registration mechanism, provides uniform access to many heterogeneous database resources, and has features such as dynamic configuration and scalability. The system is composed of Metadata Information Service (MIS), Data Access Service (DAS), Clients and the low-level distributed heterogeneous database resources.This paper stresses on discussing the architecture, access protocol and implementation mechanism based on XML and Web Services technologies, researches key technologies of metadata information service and data uniform access and management in database grid,designs and implements distributed MIS subsystem and DAS subsystem,which support multi-domain management.MIS can provides metadata information for the whole system, such as DAS and Clients,it uses domain name,logical name and internal name of data object to uniformly name database resources in grid and implements name mapping mechanism and user view metadata information service and provides virtual organization and management of database resources.DAS can provide a scalable uniform data access by virtual organization and management of storage resources and multi-mode data share access mechanism,thus integrate database resources in grid and shields distribution and heterogeneity of resources and achieves transparent access.System adopts data access mechanism based on user request mapping to flexibly implement data access across multi domains,and adopts distributed data cache mechanism,security mechanism based GSI to provide high-performance secure data service for grid users.