yum安装sentinel

要在CentOS上安装Sentinel，需要执行以下步骤：

1. 安装epel-release和redis

sudo yum install epel-release
sudo yum install redis

2. 从GitHub上下载Sentinel

cd /usr/local/src
sudo git clone https://github.com/redis-sentinel/redis-sentinel.git
cd redis-sentinel
sudo make
sudo make install

3. 创建Sentinel配置文件

sudo mkdir /etc/redis
sudo cp sentinel.conf /etc/redis/
sudo chmod 777 /etc/redis/sentinel.conf

4. 配置Sentinel

编辑`/etc/redis/sentinel.conf`文件，添加以下内容：

sentinel monitor mymaster 127.0.0.1 6379 2
sentinel down-after-milliseconds mymaster 60000
sentinel failover-timeout mymaster 180000
sentinel parallel-syncs mymaster 1

5. 启动Sentinel

redis-sentinel /etc/redis/sentinel.conf

注意：在上面的命令中，`/etc/redis/sentinel.conf`是Sentinel的配置文件路径，如果你的路径不同，请相应地修改命令。