| With the development of computer and information technology, database as the main management system of enterprises and institutions to store data is gradually popular. Ensuring the security of database data is more and more important.Nowadays, the best way to guarantee data safety is continuous data protection(CDP). The main research is focused on file-level and block-level, few studies is based on application-level. For the mechanism of database system,file-level and block-level CDP solutions have many deficiencies, such as it is difficult to ensure data consistency in backup, high cost of deployment and implementation, high spending of system and storage, and so on. Application-level CDP is built based on specific application, using the application data storage mechanism to establish change data capture and recovery mechanism. It can resolve those problems in the largest degree. So it is of significance to build an application-level CDP system for database application.This thesis designs application-level CDP system for SQL Server database system based on SQL Server database transaction log. The main work is as follows:(1) Via consulting related literature in the field of database disaster recovery, the advantages of CDP compared to tradition disaster recovery mode are summarized,the realization of file-level, block-level and application-level CDP is analyzed, the performance of the three implementations of CDP in database disaster recovery is compared, the necessary to build an application-level CDP system is verified.(2)Based on the requirement analysis, the data storage mechanism of SQL Server database is studied, the ways to capture change data on database transaction log,load data in offsite and rollback database status to any point in time are analyzed.Based on those studies, this thesis builds the whole structure of the system,elaborates specific modules for the system realization, analyzes the design and realization of key modules in depth.(3) Setting up a test environment, the function modules and the whole performance of the system are tested by specific experiments.The application-level CDP system for SQL Server database designed in this thesis with the function to capture any data change in seconds and rollback database to any status in the last moment. The system realized based on SQL Server database transaction log, which is improving the consistency of system data and reducing the amount of data transfer at maximum extent; The way to analyze transaction log in offsite server reduces the burden of the local server system; The cost is reduced bypure software implementation of the disaster recovery system. |
