任何分布式系统，都需要“锁”，用于持久化全局配置，协调分布式应用逻辑，保证所有系统高可用,它是分布式高可用系统的基石.
Paxos 算法用于实现分布式锁, 它在这个领域至关重要:
all working protocols for asynchronous consensus we have so far encountered have Paxos at their core. (Google ...