关于mybb主从数据配置

今天微博上有朋友问到我Mybb如何配置主从
其实我对mybb不是很熟悉，就大致看了一下DB
发现是可以配置主从的
在inc/config.php
中配置如下
$config['database']['read']['hostname'] = 'localhost';
$config['database']['read']['username'] = 'root';
$config['database']['read']['password'] = '';

$config['database']['write']['hostname'] = 'localhost';
$config['database']['write']['username'] = 'root';
$config['database']['write']['password'] = '';
//read为从 write为主 多个的时候['read'][0]['hostname']这样以数据配置即可

但是在db_mysql.php中我却发现在处理主从的时候。有一个不和谐的代码。目前我也没有想明白目的
175行

if(array_key_exists('hostname', $connections[$type]))
   {
    $details = $connections[$type];
    unset($connections);//这里unset了 就肯定只能够连接到read的第一个数据库上
    $connections[$type][] = $details;
}

我没有搞明白目的所以没有进行修改。如果要实现
要实现只需要重新处理一下$connections数组就可以解决
我这里就不累述。

foreach(array('read', 'write') as $type)
		{
			print_r($connections);if(!is_array($connections[$type]))
			{
				break;
			}
			
			if(array_key_exists('hostname', $connections[$type]))
			{
				$details = $connections[$type];
				unset($connections);
				$connections[$type][] = $details;
			}

			// Shuffle the connections
			shuffle($connections[$type]);

			// Loop-de-loop
			foreach($connections[$type] as $single_connection)
			{
				$connect_function = "mysql_connect";
				if($single_connection['pconnect'])
				{
					$connect_function = "mysql_pconnect";
				}
				
				$link = $type."_link";

				$this->get_execution_time();

				$this->$link = @$connect_function($single_connection['hostname'], $single_connection['username'], $single_connection['password'], 1);

				$time_spent = $this->get_execution_time();
				$this->query_time += $time_spent;

				// Successful connection? break down brother!
				if($this->$link)
				{
					$this->connections[] = "[".strtoupper($type)."] {$single_connection['username']}@{$single_connection['hostname']} (Connected in ".number_format($time_spent, 0)."s)";
					break;
				}
				else
				{
					$this->connections[] = "<span style=\"color: red\">[FAILED] [".strtoupper($type)."] {$single_connection['username']}@{$single_connection['hostname']}</span>";
				}
			}
		}