내용을 요약 하자만.. mysql이 접속 할때 reverse DNS lookup을 하는데 이때 시간이 많이 걸리니
이를 skip처리 하면 접속 속도가 많이 빨라 진다는 이야기..
Our support team was recently working on a case where pages were taking 5 seconds or longer for each load, even after tackling all of the common performance tweaks. Digging in a bit further, they realized that connecting to the MySQL database was taking an awful long time from looking at the logs.
As you can see, it’s taking nearly 5 seconds for MySQL to do a reverse DNS lookup on the client, which is completely unneeded. Fortuantely, there is a simple fix to this problem; just add the following line into your MySQL configuration file and restart the server.
[mysqld] # Skip reverse DNS lookup of clients skip-name-resolve
With that one change, the page load times ducked underneath a half a second. So definitely check your MySQL servers and make sure this is set this way.