Disable MySQL DNS reverse resolution (unauthenticated user solution)

By default, mysql will automatically reverse parse. If we cannot handle the problem, we will find a large number of unauthenticated user prompts when viewing show processlist, the following describes how to solve unauthenticated user.

Example

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Mysql> show processlist; | 20681949 | unauthenticated user | A. B .C.D: 52497 | NULL | Connect | Reading from net | NULL | | 20681948 | unauthenticated user | W. X.Y. Z: 52495 | NULL | Connect | Reading from net | NULL |

How many unauthenticated users try to log on to mysql? R. When this happens unlimitedly, the system will be very slow.

I learned from the official mysql website that this is a special setting on an official system. I thought of it as a mysql bug. No matter whether the link is through the hosts or IP mode, he will reverse query the DNS. mysqld will try to reverse query the IP address-> dns, because reverse query resolution is too slow, you cannot cope with excessive queries.

If a large number of illegal users attempt to log on to MySQL on the Internet, the load on the server is unimaginable.

Solution:
1. execution:

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#/Usr/local/mysql/bin/mysqld_safe -- skip-name-resolve -- user = mysql &

Ii. Modify the MySQL configuration file my. cnf
Append:

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[Mysqld] Skip-name-resolve