MySQL host is blocked because of your connection errors; unblock with 'mysqladmin flush-hosts &

From: http://www.cnblogs.com/susuyu/archive/2013/05/28/3104249.html

Environment:Linux, mysql5.5.21

Error:Host is blocked because of your connection errors; unblock with 'mysqladmin flush-hosts'

Cause:

The same IP address causes too many database connections (exceeding the maximum value of the MySQL database max_connection_errors) in a short period of time;

Solution:

1. Increase the number of max_connection_errors allowed (temporary ):

① Go to the MySQL database to view max_connection_errors:Show variables like '% max_connection_errors % ';

② Modify max_connection_errors to 1000:
Set global max_connect_errors = 1000;

③ Check whether the modification is successful:Show variables like '% max_connection_errors % ';

2. UseMysqladmin flush-hostsRun the following command to clear the hosts file:Whereis mysqladmin);

① Use the command to modify the Directory:/usr/bin/Mysqladmin flush-hosts-h192.168.1.1-P3308
-Uroot-Prootpwd;

Note:

You can add and modify the port number, user name, and password as needed;

If the Master/Slave database is configured, you must modify both the master database and slave database. (I have suffered this loss. It is easy to get a few command results that have been tossing for a long time );

The second step can also be performed in the database. The command is as follows:Flush hosts;