Perfect solution to the problem of connection failure after mysql client authorization

Deploy the mysql environment locally (192.168. 1.152), authorize the remote client 192.168. 1% to connect to the native mysql, and open port 3306 in the iptables firewall.

As follows:

mysql > select host,user,password from mysql.user;
+--------------+-----------------+---------------------------------------------------------+
| host | user | password |
+--------------+-----------------+----------------------------------------------------------+
| localhost | root | |
| fdm1 | root | |
| 127.0.0.1 | root | |
| localhost | | |
| fdm1 | | |
| 192.168.1.% | db_hqsb | *DFC9DC16B13651A95ECEC3A26E07D244431B55C9 |
| 192.168.1.% | db_ro_hqsb | *2C0B0DD50595BB40879110437BEEF026D019DFB7 |
| 192.168.1.% | db_jkhwuser | *2C0B0DD50595BB40879110437BEEF026D019DFB7 |
| 192.168.1.25| slave | *EE52B8EACB3CCD13624273AD6B5CDA52B9B53EB7 |
| 192.168.1.% | tech_db_user | *6053E57C7B61043DC2C6B4E3291D5F61CCC23F5C |
| 192.168.1.% | game_db_user| *05EA4D71C9A1273ECF3E24E6323F7175AE45C366 |
| localhost | zabbix | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 |
+---------------+---------------+------------------------------------------------------------+

Question:

Connect remotely to the mysql of the upper 192.168. 1.152 machine on the client (such as 192.168. 1.20), and the connection fails!

[root@huanqiu ~]# mysql -udb_ro_hqsb -h 192.168.1.152 -pmhxzkhl0802xqsjdb
ERROR 1130 (HY000): Host '192.168.1.20' is not allowed to connect to this MySQL server

Resolve:

It is caused by the statement "host is localhost, user and password are empty" in mysql of 192.168. 1.152. Delete this article to solve the problem!

mysql > delete from mysql.user where host="localhost" and user="";
Query OK, 1 row affected (0.00 sec)
mysql > flush privileges;
Query OK, 0 rows affected (0.00 sec)

In this way, the authorized client can connect successfully!

[root@huanqiu ~]# mysql -uxqsj_db_ro_user -h 192.168.1.152 -pmhxzkhl0802xqsjdb
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 28
Server version: 5.1.73 Source distribution

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