今天 搭建redis sentinel 一直卡在-sdown sentinel ，无法主从自动切换。
配置如下：
port 26379
daemonize yes
logfile "/home/redis/logs/sentinel.log"
sentinel announce-ip 192.168.0.201
sentinel monitor mymaster 192.168.0.201 6379 2
sentinel auth-pass mymaster Redis@jujinziben
sentinel down-after-milliseconds mymaster 15000
sentinel failover-timeout mymaster 900000
sentinel can-failover mymaster yes
sentinel parallel-syncs mymaster 1
结果启动后一直卡在那边不动：
后来了解到sentinel的保护模式，改成如下：
port 26379
daemonize yes
protected-mode no
logfile "/home/redis/logs/sentinel.log"
sentinel announce-ip 192.168.0.201
sentinel monitor mymaster 192.168.0.201 6379 2
sentinel auth-pass mymaster Redis@jujinziben
sentinel down-after-milliseconds mymaster 15000
sentinel failover-timeout mymaster 900000
sentinel can-failover mymaster yes
sentinel parallel-syncs mymaster 1
关掉保护模式后重新启动哨兵正常。