内容来自 https://www.slideshare.net/jboner/scalability-availability-stability-patterns/196 的 195、196 页
N = the number of nodes that store replicas of the data
W = the number of replicas that need to acknowledge the receipt of the update before the update completes
R = the number of replicas that are contacted when a data object is accessed through a read operation
W + R > N strong consistency
W + R <= N eventual consistency
理解
N 存储复制数据节点的数量
W 在更新操作完成前，确认受到更新操作的节点的数量
R 进行一个读取操作时，接触的副本节点的数量
当 确认节点 + 读取涉及的节点的数量，大于 副本节点的总数时，是强一致
当 确认节点 + 读取节点的数量， 小于等于 副本节点的总数时，是最终一致性
Select Language