protected function connect()
{
$db = new \swoole_mysql();
$db->on('close', function ($db) {
$this->remove($db);
});
return $db->connect($this->config, function ($db, $result) {
if ($result) {
$this->join($db);
} else {
$this->failure();
trigger_error("connect to mysql server[{$this->config['host']}:{$this->config['port']}] failed. Error: {$db->connect_error}[{$db->connect_errno}].");
}
});
}
