怎么使用nginx充当mysql的负载均衡器

./configure --prefix=/data/apps/nginx --with-http_stub_status_module --with-http_ssl_module --with-http_realip_module --with-http_image_filter_module --with-stream

stream{include /data/apps/nginx/conf/stream/*.conf;}

server {listen 3307; #注意端口不能跟mysql监听的一样proxy_pass db;}upstream db {server 127.0.0.1:3306;server 192.168.233.1:3306;}

#其实就是new mysqli的时候只需改端口号与nginx反向代理设置的端口号一样就可以了$mysqli = new mysqli('127.0.0.1','root','root','test',3307);

<?phpclass mysqlclass{private static $obj = null; //mysqlclass对象public $host;public $database;public $user;public $pwd;public $port;public $mysqli = null;//禁止对象被克隆private function __clone(){}//禁止外部实例化private function __construct($host="127.0.0.1",$database="test",$user="root",$pwd="root",$port="3307"){$this->host = $host;$this->database = $database;$this->user = $user;$this->pwd = $pwd;$this->port = $port;$this->mysqli = $this->db_connect();}//获取mysqli连接private function db_connect(){$mysqli = new mysqli($this->host,$this->user,$this->pwd,$this->database,$this->port);if($mysqli->connect_errno){printf("connect failed: %s
", $mysqli->connect_errno);exit();}$mysqli->query("set names utf8 ");return $mysqli;}//获取db实例public static function get_db(){if(self::$obj === null){self::$obj = new self();}return self::$obj;}public function db_query($sql){$result = $this->mysqli->query($sql);$arr = [];while ($row = $result->fetch_assoc()) {$arr[] = $row;}$result->close();$this->mysqli->close();return $arr;}public function db_insert(){}public function db_update(){}public function __destruct() {$this->mysqli->close();}}$db = mysqlclass::get_db();$r = $db->db_query("show tables");var_dump($r);