Research And Application Of Distributed Database Synchronization Technology Based On Snapshot Isolation

In recent years, the distributed database applications are increasing with the rapiddevelopment of the computer network. Redundant copies of data, usually introduced in thedesign and implementation of a distributed database system. Multiple copies of data in differentlocations at the same time providing services can improve system availability and reliability,how to ensure the consistency of the redundant copies of data is a core issue in the distributeddatabase system.To solve the problem of data consistency in distributed database system, snapshot isolationis introduced into the database synchronization technology, through its concurrency features toimprove the performance of database synchronization system; some scholars adopt groupcommunication in the total order transferring technology to achieve a good database peer nodesynchronization strong data consistency. But the snapshot isolation did not achieve databaseconcurrency control the serializability correctness criterion, may lead to inconsistencies; andusing only the group communication technology will have some impact on the performance ofthe system.Therefore, this paper analyzes the snapshot isolation technology and communicationtechnology for multi-node distributed database synchronization business needs, combined withthe advantages of both, designed and implemented a maintenance redundancy in a distributeddatabase replica consistency systems. The main work is summarized as follows:(1) We design a principle of serializable snapshot isolation (SSI). In order to ensure theconcurrent transactions of snapshot isolation to be serializable, we present “serializable snapshotisolation principle”based on the study of snapshot isolation technology. The principle guaranteesone-copy serializablility of concurrent transactions.(2) We design the distributed database synchronization protocol for update anywhere model.Combine the characteristics of group communication based on the snapshot isolation serializablealgorithm, we design the SSI-SYNC database synchronization protocol, ensure that transactionscan be submitted to any replica as well as guaranteeing the performance of the system.(3) For maintenance of distributed database data consistency, we proposed a synchronizationconflict management strategy in a distributed environment and design a synchronous exceptionhandling strategy for distributed database. We can ensure good data consistency of replica withthese strategies.(4) We design and implement a distributed database synchronization system based onsnapshot isolation. In order to solve the problem of secure transmission of data synchronizationprocess, we design a data transmission security authentication mechanism. Data synchronization protocol and digital envelope mechanism is combining to achive the high requirements for datasecurity. The system can be safe, reliable, stable and efficient synchronization between Oracle,SQL Server and other mainstream database products, and system synchronization validation andanalysis of verification results. The experimental results show that the system can fully guaranteethe user’s autonomy under the premise of the complete synchronization of the distributeddatabase.