这篇文章 Seth Gilbert 和 Nancy Lynch 形式化证明了 Brewer 的 CAP 理论。讨论了异步网络环境和半异步网络环境下 CAP 理论的正确性。鄙人英语 so so ,再加上文章比较枯燥,仅翻译下所列出的定理:
Theorem 1 It is impossible in the asynchronous network model to implement a read/write data object that guarantees the following properties:
• Availability
• Atomic consistency in all fair executions (including those in which messages are lost).定理1 在异步网络模型中应用一个读/写数据对象并满足以下特性是不可能的:
• 可用性
• 在所有请求平等下的原子一致性(包括消息丢失情况)Corollary 1.1 It is impossible in the asynchronous network model to implement a read/write data object that guarantees the following properties:
• Availability, in all fair executions,
• Atomic consistency, in fair executions in which no messages are lost.推论1.1 在异步网络模型中应用读/写数据对象并满足以下特性是不可能的:
• 对所有平等请求满足可用性
• 没有消息丢失下所有平等请求满足原子一致性
Theorem 2 It is impossible in the partially synchronous network model to implement a read/write data object that guarantees the following properties:
• Availability
• Atomic consistency in all executions (even those in which messages are lost).定理2 在半异步网络模型中应用一个读/写数据对象并满足以下特性是不可能的:
• 可用性
• 在所有请求平等下的原子一致性(包括消息丢失情况)
Theorem 4 The modified centralized algorithm is Delayed-t consistent.
定理4 改进的中心算法是延迟 t 时间一致性的。