Event-driven Data Replication System

With the society entering information age, so the information technology is playing a more important role in the society than it used to be. As an important part of information technology, data disaster tolerance system is becoming more and more important, because it can guarantee data safe in any condition such as hardware failure, network interruption, fire, earthquake and war.Based on researching the current Disaster Tolerance systems and related technologies, the paper presents a data disaster tolerance system on Windows, named Windows Storage Replicator (WSR). The paper introduced and discussed basic concepts, system's architecture, work flow and key technologies of WSR system, at last, it shows the performance test result and the analysis of the result.The basic principle of WSR is to embed Remote Replication mechanism and Disaster Recovery mechanism in the Volume Manager, the work flow is drive by event.The key technology of WSR are the technology of embedding replication mechanism in Windows kernel, the method of keeping the data Consistency in Replication Volume Group, the protocol of remote replication (transmission) based on volumes and disaster recovery policy.The main contribution of the thesis can be summarized as follows:1. In order to improve the performance of data replication, the pipeline is proposed;2. In order to resolve the problem of data inconsistent after the interruption of pipeline, the atomic operation is proposed;3. In order to simplify the event handling, the state machine is proposed;4. In order to make WSR more agile and flexible, the Strategy pattern is proposed;5. In order to explain the abnormal behaving of asynchrony replication mode, system stability and wastage are discussed.