高可用数据库系统中的分布式一致性协议

On the distributed consensus protocol in high-availability database systems

可用性和一致性是分布式数据库系统中的两个重要特性和基础,需要借助分布式一致性协议来保证.保证一致性需要使用一致性协议为并发的事务更新操作确定一个全局的执行顺序,并协调局部状态和全局状态不断地达到动态一致.可用性的实现,需要一致性协议协调多副本之间的一致来实现主备节点的无缝切换.可见,分布式一致性协议是高可用数据库系统的实现基础.本文梳理、综述了经典的分布式一致性协议以及一致性协议在高可用数据库系统中的主要应用,并对分布式一致性协议的实现代价和局限性进行了分析与评估.

Availability and consistency are the two important characteristics of the distributed database systems, which need to be guaranteed by the distributed consensus protocol. Ensuring consistency requires a consensus protocol to determine a global execution sequence for concurrent transaction updates, and to coordinate the consistency between local states and the global state continuously. For the implementation of the availability, we need to coordinate the consistency between the multiple backups to achieve the seamless switch between the main and backup nodes. Visible, distributed consistency protocol is the basis for the realization of high availability database system. Distributed consensus protocol is the base of high availability database systems. This paper summarizes the classical consistency protocols and the main applications in high-availability systems of the distributed consistency protocols. Meanwhile, the implementation costs and limitations of the consistency protocols are analyzed and evaluated.