-- 创建测试库mysql> create database test;Query OK, 1 row affected (0.00 sec)mysql> use test;Database changed-- 创建审计记录表mysql> CREATE TABLE `conn_log` (-> `conn_id` int(11) DEFAULT NULL,-> `conn_time` datetime DEFAULT NULL,-> `user_name` varchar(128) CHARACTER SET utf8 DEFAULT NULL,-> `cur_user_name` varchar(128) CHARACTER SET utf8 DEFAULT NULL,-> `ip` varchar(15) CHARACTER SET utf8 DEFAULT NULL,-> KEY `conn_time` (`conn_time`)-> ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 ;Query OK, 0 rows affected (0.01 sec)-- 设置审计内容mysql> set global init_connect="set @user=user(),@cur_user=current_user();insert into test.conn_log values(connection_id(),now(),@user,@cur_user,'10.0.0.1');"-> ;Query OK, 0 rows affected (0.00 sec)mysql> show variables like '%init%';+------------------------+-------------------------------------------------------------------------------------------------------------------------------+| Variable_name| Value |+------------------------+-------------------------------------------------------------------------------------------------------------------------------+| init_connect | set @user=user(),@cur_user=current_user();insert into test.conn_log values(connection_id(),now(),@user,@cur_user,'10.0.0.1'); || init_file| || init_slave | || table_definition_cache | 1400|+------------------------+-------------------------------------------------------------------------------------------------------------------------------+4 rows in set (0.00 sec)-- 创建普通用户mysql> grant select,insert on dba_test.* to 'test'@'%' identified by 'test';Query OK, 0 rows affected, 1 warning (0.00 sec)mysql> flush privileges;Query OK, 0 rows affected (0.01 sec)

[root@test ~]# mysql -S /data0/mysql57/mysql3307/mysqltmp/mysql3307.sock-utest -ptest Welcome to the MySQL monitor.Commands end with ; or \g.Your MySQL connection id is 117Server version: 5.7.21-logCopyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.Oracle is a registered trademark of Oracle Corporation and/or itsaffiliates. Other names may be trademarks of their respectiveowners.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.mysql> show user();ERROR 2006 (HY000): MySQL server has gone awayNo connection. Trying to reconnect...Connection id:118Current database: *** NONE ***ERROR 1184 (08S01): Aborted connection 118 to db: 'unconnected' user: 'test' host: 'localhost' (init_connect command failed)mysql> select user();ERROR 2006 (HY000): MySQL server has gone awayNo connection. Trying to reconnect...Connection id:119Current database: *** NONE ***

通过查看erro log发现test用户没有test.conn_log表的写权限，导致init-connect中的sql内容无法进行，
从而导致连接失败

-- 赋权mysql> grant insert on test.* to 'test'@'%';Query OK, 0 rows affected (0.00 sec)mysql> flush privileges;Query OK, 0 rows affected (0.00 sec)-- 登陆正常[root@test ~]# mysql -hip地址 -P3307-utest -ptestWelcome to the MySQL monitor.Commands end with ; or \g.Your MySQL connection id is 140Server version: 5.7.21-log MySQL Community Server (GPL)Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.Oracle is a registered trademark of Oracle Corporation and/or itsaffiliates. Other names may be trademarks of their respectiveowners.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.mysql> use dba_test;Reading table information for completion of table and column namesYou can turn off this feature to get a quicker startup with -ADatabase changedmysql> show tables;+--------------------+| Tables_in_dba_test |+--------------------+| user |+--------------------+1 row in set (0.00 sec)mysql> insert into user(user_id,username) values(4,'d');Query OK, 1 row affected (0.00 sec)mysql>