时钟同步的假设检验研究

时钟同步技术是分布式系统中非常活跃的研究领域之一，由于大多数分布式系统实际上是不同步的，因此需要采用容错时钟同步算法确保消息通信的有界延迟，而基于假设检验的时钟同步技术可以避免因错失对两个高概率不同步时钟进行同步调整而造成系统不正常使用的情况。该文讨论了时钟同步的假设检验问题。除了假设检验、两类错误概率，还给出了概率最小时钟偏差、时钟同步概率等概念。在时钟偏差的统计分布特性近似于服务正态分布的假设条件之下，提出了基于非中心t分布的时钟同步假设检验方案。最后，基于服务器和客户端之间双向消息通信传输模式，给出时钟偏差的估计和检验样本。

Hypothesis Test of Clock Synchronization

Clock synchronization technology is an active research area in distributed systems. Because most distributed systems encountered in practice are asynchronous, they have to adopt fault - tolerant clock synchronization algorithms to guarantee a bound on message communication delays. And clock synchronization technology based on hypothesis test can avoid the abnormal case of a system caused by missing clock synchronization on two asynchronous clocks with high probability. Hypothesis test of clock synchronization is discussed in this paper. Besides the hypothesis test and two types of error probability, the definitions of probabilistic minimum clock deviation, clock synchronization, etc. are also given. Under the assumption that the probability distribution of the clock deviation approaches the normal distribution, a hypothesis testing scheme of dock synchronization based on non - central t - distribution is presented. Finally, based on the bidirectional message communication transmission mode, both an estimate sample and a testing sample of the clock deviation are given.