$ cat /etc/my.cnf

 [mysqld]
pid-file                         = /var/run/mysqld/mysqld.pid
socket                         = /var/run/mysqld/mysqld.sock
datadir                         = /var/lib/mysql
symbolic-links              = 0
local-infile                    = 0
max_connections        = 1000
skip_name_resolve
character-set-client-handshake  = FALSE
lower_case_table_names          = 1
sql-mode                        = "ONLY_FULL_GROUP_BY,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION,STRICT_ALL_TABLES"
character-set-server            = utf8
collation-server                    = utf8_general_ci
init_connect                         = "SET NAMES 'utf8'"


plugin-load-add=connection_control.so
connection-control-failed-connections-threshold=3
connection-control-min-connection-delay=1000
connection-control-max-connection-delay=2147483647
connection-control=FORCE_PLUS_PERMANENT
connection-control-failed-login-attempts=FORCE_PLUS_PERMANENT


plugin-load-add=validate_password.so
validate-password=FORCE_PLUS_PERMANENT
validate_password_check_user_name=on
validate_password_length=8
validate_password_number_count=1
validate_password_mixed_case_count=1
validate_password_special_char_count=1
validate_password_policy=2
validate_password_dictionary_file=/var/lib/mysql/dictionary_file


server-id=2020
log-bin=/var/lib/mysql/mysql-bin
expire_logs_days=7

## 此日志只在调试模式下打开
# general_log       = on
# general_log_file  = /var/lib/mysql/general.log
# log_timestamps    = SYSTEM


require_secure_transport = ON
ssl-ca                   = /var/lib/mysql/ca.pem
ssl-cert                 = /var/lib/mysql/server-cert.pem
ssl-key                  = /var/lib/mysql/server-key.pem


[mysql]
default-character-set           = utf8

[client]
default-character-set           = utf8

注： 此配置只关注安全加固，不涉及性能调优。

参考

MySQL 5.6 Reference Manual / Connection-Control Plugin Installation
https://dev.mysql.com/doc/refman/5.6/en/connection-control-installation.html

MySQL 5.7 Reference Manual / Connection-Control Plugin Installation
https://dev.mysql.com/doc/refman/5.7/en/connection-control-installation.html

MySQL通过CONNECTION_CONTROL限制连接次数
https://zhuanlan.zhihu.com/p/157563612
https://www.cnblogs.com/wshichang/p/14276055.html

mysql8 参考手册--连接控制插件
https://www.1024sky.cn/blog/article/939