Resolves a large number of MySQL unauthenticated user issues

Recently OJ and related open station abnormal slow, simply collapsed, has not found the reason!

Go to the database server, go to MySQL, check it with show processlist command, find a lot of unauthenticated user

Google a bit,

Found that this is a MySQL bug, regardless of whether the connection is through the hosts or IP, MySQL will do DNS counter-check, IP to DNS, due to the inverse of the slow speed

(Whether it is a DNS server provided by the ISP or other reasons), a large number of queries are difficult to cope with, the thread is not enough to increase the thread, but not released, so MySQL will "suspended animation."

The solution is simple, to end this counter-check process, prohibit any parsing.

Open the MySQL configuration file (my.cnf) and add a line under [mysqld]:

Skip-name-resolve

Reload the configuration file or restart the MySQL service.

Resolves a large number of MySQL unauthenticated user issues