The Research Of Data Synchronization Of Distributed Spatial Data Servers Based On G/S Mode

Nowadays, the primary systems of spatial information network service are C/S Mode and B/S Mode. But, the localization of C/S Mode and B/S Mode which are used on the network accessing of spatial information has existed. And the data synchronization of distributed servers, the important part of the spatial information network system, has three methods of data copy at present which only suit some specifically areas.So, the Prof. Miaofang designs the G/S Mode, a new network accessing mode of spatial information. This paper brief introduces the basic conception and technology characteristic of the G/S Mode: introducing HGML as the uniform standard of spatial information exhibition, exchange, organizing and management; introducing the distributed spatial information servers based on internet environment as the service provider of spatial information organizing, management, transmission; introducing the Geo-Browser as the platform of spatial information exhibition, 3D display,"G"section aggregation service. These contents ulteriorly illuminate that the G/S Mode tally with the trend of network accessing of spatial information.Aim at the characteristic of the application based on G/S Mode, this paper introduces and summarizes the problems that the"S"section should solve and how to do. The storage complexity should be solved by distributed storage which is supported by distributed file system. The network complexity should be solved by the multi-network server emplacing. The computing complexity should be solved by the distributed computing which has the characteristic called assignment disassembly and result combination. According to the above demonstration, this paper proves the feasibility of distributed servers which has used by G/S Mode as "S" section. Based on the analysis of research actuality and existent problems of data synchronization of distributed servers with G/S Mode, this paper depicts the main research matter and production.Main research matter:l The lock of the data on data synchronization;l The data synchronization of servers on the simple application or the initial complex application;l The multicast and incepting of synchronization signal from updating source;l The feasible occasion of data synchronization;l The method of data synchronization.Main research production:l Introduced a scheme of data synchronization on the complex application, including synchronization signal multicasting and incepting, the warranty of synchronization occasion choosing, and the method of data synchronization;l Introduced a scheme of stepwise synchronization on the simple application or the initial complex application;l Introduced a method of data locking on the data synchronization;At last, according to the requirement of data synchronization of distributed servers based on G/S Mode, this paper validates the two schemes introduced with experiment.