如何使用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);

  <?php  class 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: %sn", $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);