一种面向关键属性更新的优化数据一致性算法

规模巨大且分布性强的P2P系统可能导致部分数据副本发布的更新被长时间地延迟,从而降低Internet上资源定位的效率。针对关键属性更新的特点,提出一种解决关键属性更新冲突的优化数据一致性算法。算法中分离出用户提交的更新请求中关于关键属性的更新,在对关键更新冲突分类的基础上,采用更新缓冲预处理和关键更新表两层机制并结合最新写胜出和分而治之规则,优化关键更新冲突的发现和解决。关键属性更新的优化处理使得不会产生因为关键属性更新的延迟而降低系统基于关键属性的资源定位效率,满足面向Internet的P2P系统的要求。模拟测试结果表明该算法在一致性维护开销、资源定位开销与资源访问开销以及鲁棒性方面均具有较好的性能。

An Optimistic Data Consistency Algorithm for Update of Key-attributes

In generally large-scale and strong distributed P2P systems,updates issued by replicas may be delayed,and then resource location performance on the Internet may be depressed.According to the characteristics of updates about key-attributes in P2P systems,an optimistic data consistency maintenance algorithm is proposed.The update about key-attributes was separated from user update request,and based on classifying key-update conflicts,a double-level mechanism including preprocessing buffer and key-update table were applied to detect and reconcile conflicts,and then conflicts were solved by policies as last-writer-win and divide-and-rule.Delaying key-attributes updates cannot occur by the optimistic disposal method,and then it cannot depress efficiency of resource location based on key-attributes,which adapts well to P2P systems for Internet.The simulation results show that it is an effective optimistic data consistency algorithm,achieving good consistency overhead,resource location and resource access overhead,and having strong robustness.