PHP实现Redis主从复制自动切换的方法

sudo pecl install redis

wget https://GitHub.com/phpredis/phpredis/arcHive/4.1.1.tar.gz
tar xvzf 4.1.1.tar.gz
cd phpredis-4.1.1/
phpize
./configure
make
sudo make install

extension=redis.so

//定义主从节点的参数
$redisMaster = [
    'host' => '127.0.0.1',
    'port' => '6379'
];
$redisSlave1 = [
    'host' => '127.0.0.1',
    'port' => '6380'
];
$redisSlave2 = [
    'host' => '127.0.0.1',
    'port' => '6381'
];

//创建主节点连接并设置自动重连
$redis = new Redis();
$redis->pconnect($redisMaster['host'], $redisMaster['port']);
$redis->setOption(Redis::OPT_AUTO_RECONNECT, true);

//创建从节点连接并设置自动重连
$redisSlave1 = new Redis();
$redisSlave1->pconnect($redisSlave1['host'], $redisSlave1['port']);
$redisSlave1->setOption(Redis::OPT_AUTO_RECONNECT, true);

$redisSlave2 = new Redis();
$redisSlave2->pconnect($redisSlave2['host'], $redisSlave2['port']);
$redisSlave2->setOption(Redis::OPT_AUTO_RECONNECT, true);

//测试连接是否正常
if(!$redis->ping()){
    //如果主节点出现故障，自动切换到备用节点
    if(!$redisSlave1->ping() && !$redisSlave2->ping()){
        //如果备用节点1和备用节点2都无法连接，则抛出异常
        throw new Exception('Redis主备节点全部宕机');
    }elseif($redisSlave1->ping()){
        $redis = $redisSlave1;
    }elseif($redisSlave2->ping()){
        $redis = $redisSlave2;
    }
}

//使用Redis主节点进行数据操作
$redis->set('foo', 'bar');
$value = $redis->get('foo');
echo $value;