use \Workerman\Worker;
use \Workerman\Connection\AsyncTcpConnection;
require_once __DIR__ . '/Workerman/Autoloader.php';

// 真實的mysql地址，假設(shè)這里是本機3306端口
$REAL_MYSQL_ADDRESS = 'tcp://127.0.0.1:3306';

// 代理監(jiān)聽本地4406端口
$proxy = new Worker('tcp://0.0.0.0:4406');

$proxy->onConnect = function($connection)
{
    global $REAL_MYSQL_ADDRESS;
    // 異步建立一個到實際mysql服務(wù)器的連接
    $connection_to_mysql = new AsyncTcpConnection($REAL_MYSQL_ADDRESS);
    // mysql連接發(fā)來數(shù)據(jù)時，轉(zhuǎn)發(fā)給對應(yīng)客戶端的連接
    $connection_to_mysql->onMessage = function($connection_to_mysql, $buffer)use($connection)
    {
        $connection->send($buffer);
    };
    // mysql連接關(guān)閉時，關(guān)閉對應(yīng)的代理到客戶端的連接
    $connection_to_mysql->onClose = function($connection_to_mysql)use($connection)
    {
        $connection->close();
    };
    // mysql連接上發(fā)生錯誤時，關(guān)閉對應(yīng)的代理到客戶端的連接
    $connection_to_mysql->onError = function($connection_to_mysql)use($connection)
    {
        $connection->close();
    };
    // 執(zhí)行異步連接
    $connection_to_mysql->connect();

    // 客戶端發(fā)來數(shù)據(jù)時，轉(zhuǎn)發(fā)給對應(yīng)的mysql連接
    $connection->onMessage = function($connection, $buffer)use($connection_to_mysql)
    {
        $connection_to_mysql->send($buffer);
    };
    // 客戶端連接斷開時，斷開對應(yīng)的mysql連接
    $connection->onClose = function($connection)use($connection_to_mysql)
    {
        $connection_to_mysql->close();
    };
    // 客戶端連接發(fā)生錯誤時，斷開對應(yīng)的mysql連接
    $connection->onError = function($connection)use($connection_to_mysql)
    {
        $connection_to_mysql->close();
    };

};
// 運行worker
Worker::runAll();

以上是代理mysql的例子，摘自手冊 http://doc.workerman.net/async-tcp-connection/connect.html 。
你說的中轉(zhuǎn)應(yīng)該類似的原理。