集群初始化之后会写入sentinel.conf文件slave信息，当master节点发生故障会重新写入sentinel.conf文件，如下
# Generated by CONFIG REWRITE
user default on nopass ~* +@all
sentinel known-replica mymaster 172.17.0.3 6399
sentinel known-replica mymaster 106.13.165.100 6379
sentinel known-replica mymaster 172.17.0.3 6379
sentinel known-replica mymaster 172.17.0.4 6399
sentinel known-replica mymaster 172.17.0.3 6389
sentinel known-replica mymaster 106.13.165.100 6399
sentinel known-replica mymaster 172.17.0.4 6379
sentinel current-epoch 4
无效的节点注意及时清理