phpredisUncaughtexception'RedisException'withmessage'Redisserverwenta解决方案

php redis Uncaught exception 'RedisException' with message 'Redis server went a
php代码：

ini_set('default_socket_timeout', -1);
$redis = new Redis();
$redis->connect("192.168.2.156","6379"); //php客户端设置的ip及端口
$redis->auth('123456');
//$redis->select(1);
$redis->set("say","Hello World");
$data = $redis->get("say"); //应输出Hello World
var_dump($data);
提示错误：Fatal error: Uncaught exception 'RedisException' with message 'Redis server went away' in /usr/local/nginx/html/index.php:56 Stack trace: #0 /usr/local/nginx/html/index.php(56): Redis->auth('123456') #1 {main} thrown in /usr/local/nginx/html/index.php on line 56
redis服务打开了，防火墙也给关闭了，phpinfo里也看到了php的redis扩展，selinux不管设置成disabled还是permissive都不好用，真不知道是哪里出问题了，请高手指点
------解决思路----------------------
商刻的未来就看你了