基于快照隔离的分布式数据库同步协议研究与实现

针对分布式数据库系统中副本一致性的问题,结合快照隔离的性能优势和组通信技术的消息定序特性,提出了一种满足单副本可串行化的数据同步协议。首先,形式化定义了快照隔离可串行化的准则,并证明了该规则可以保证单副本可串行化。进而基于组通信系统的消息定序特性,提出了满足单副本可串行化的数据同步协议SSI-REP。实验表明,与两阶段协议(2PL)相比,SSI-REP协议提高了系统的性能,降低了事务的系统响应时间;与全局快照隔离算法GSI相比,SSI-REP协议在保证单副本可串行化的前提下,对系统性能的影响甚微。

Research and implementation of distributed databasesynchronization protocol based on snapshot isolation

To solve the problem of data consistency in distributed database system, this paper presented a distributed database synchronization protocol providing one-copy-serializability based on the performance of SI and the message ordering feature of group communication. At first, this paper formally defined serializable snapshot isolation SSI and then proved the correctness of the algorithm. Then it proposed SSI-REP based on SSI and the feature of group communication. Experimental results show that SSI-REP has clearly better performance than 2PL and nearly the same performance comparing to GSI.