Abstract:To solve the problems of traditional data disaster recovery system with large backup window and low disaster immunity, an application-level continuous data protection disaster recovery system combined with SQL Server database is introduced and designed. Application program interface provided by SQL Server is used to read the database transaction log file in the system, then date changes are captured online. The captured data change is recorded in log file and stored in cache-quene. It will be sent to other places to achieve remote offsite disaster recovery. When a disaster occurs, the system uses heartbeat detection, floating IP technologies to take over the broken system. When a malfunction occurs, the system can return to any time point according to the log file. So the system can effectively avoid data loss which caused by man-made or accident.