redis 实现分布式锁

1、redis 单机
http://www.redis.cn/articles/20181020004.html
https://www.jianshu.com/p/47fd7f86c848

2、redis集群环境（主从、cluster）

http://redis.cn/topics/distlock.html
https://www.cnblogs.com/leyangzi/p/11172470.html