[mysqld]
skip-name-resolve

      在linux下配置文件是/etc/my.cnf，在windows下配置文件是mysql安裝目錄下的my.ini文件。注意該配置是加在 [mysqld]下面，在更改配置并保存后，然后重啟mysql并遠程連接測試，一切恢復如初。該參數的官方解釋信息如下：

How MySQL uses DNS

When a new thread connects to mysqld, mysqld will spawn a new thread to handle the request. This thread will first check if the hostname is in the hostname cache. If not the thread will call gethostbyaddr_r() and gethostbyname_r() to resolve the hostname.

If the operating system doesn't support the above thread-safe calls, the thread will lock a mutex and call gethostbyaddr() and gethostbyname() instead. Note that in this case no other thread can resolve other hostnames that is not in the hostname cache until the first thread is ready.

You can disable DNS host lookup by starting mysqld with