It can be seen that the causes are:

Blocking caused by too many (exceeding the maximum value of max_connect_errors for mysql database) broken database connections from the same ip in a short period of time

Solution 1: Change the value of max_connect_errors
(1) Go to the Mysql database and check the max_connect_errors.

show variables like ‘%max_connect_errors%’;

(2) Modify the value of max_connect_errors:

set global max_connect_errors = 100;

(3) Check whether the modification is successful or not

show variables like ‘%max_connect_errors%’;

Solution 2: use mysqladmin flush-hosts command to clean up the hosts file

(1) Use the command to modify under the found Directory: mysqladmin -u xxx -p flush-hosts

perhaps

flush hosts;

Solution: mysqld> Restart

I solved it by restarting mysql