Question

MySQL在MySQL-5.7中有一个新变量，用于保存mysql用户的密码到期详细信息 - 在特定用户密码过期的几天之后。

此变量的详细信息：Doc

当我们更改此变量时，是否需要运行刷新权限，或者更改是否会立即对所有具有默认过期策略的用户生效？

Answer 1

我认为答案是肯定的。

因为default_password_lifetime是一个全局变量，这些信息存储在information_schema.GLOBAL_VARAIBLES中，它是一个内存引擎表！

在mysql中，flush操作会导致缓冲区中的数据写回磁盘，只有在MyISAM引擎中才需要;但是，flush privileges子句会将磁盘MyISAM文件中的数据重新加载到内存中。 ;特权相关表。

Answer 2

根据文件，没有必要：

6.3.6 Password Expiration Policy

...

当客户端成功连接时，服务器确定是否成功   帐户密码已过期：



服务器检查密码是否已手动过期，如果是，则限制会话。



否则，服务器会根据自动密码过期策略检查密码是否超过其生命周期。如果是这样，   服务器认为密码已过期并限制会话。



...

重要提示：此更改仅对后续连接生效。

这是一个例子：

$ mysql
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 13
Server version: 5.7.18

Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> SELECT @@GLOBAL.default_password_lifetime;
+------------------------------------+
| @@GLOBAL.default_password_lifetime |
+------------------------------------+
|                                  0 |
+------------------------------------+
1 row in set (0.00 sec)

mysql> CREATE USER 'johndoe'@'localhost'
    -> IDENTIFIED WITH mysql_native_password AS '*6C8989366EAF75BB670AD8EA7A7FC1176A95CEF4'
    -> PASSWORD EXPIRE DEFAULT;
Query OK, 0 rows affected (0.00 sec)

mysql> exit
Bye

$ mysql -u johndoe -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 14
Server version: 5.7.18

Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> SELECT CURRENT_USER();
+-------------------+
| CURRENT_USER()    |
+-------------------+
| johndoe@localhost |
+-------------------+
1 row in set (0.00 sec)

mysql> exit
Bye

$ mysql
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 15
Server version: 5.7.18

Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> SET @@GLOBAL.default_password_lifetime := 1;
Query OK, 0 rows affected (0.00 sec)

mysql> SELECT @@GLOBAL.default_password_lifetime;
+------------------------------------+
| @@GLOBAL.default_password_lifetime |
+------------------------------------+
|                                  1 |
+------------------------------------+
1 row in set (0.00 sec)

mysql> SELECT NOW();
+---------------------+
| NOW()               |
+---------------------+
| 2010-01-01 00:00:01 |
+---------------------+
1 row in set (0.00 sec)

mysql> \! date -s "2010-01-02 $(date +%H:%M:%S)"
Sat Jan 02 00:00:05 UTC 2010
mysql> SELECT NOW();
+---------------------+
| NOW()               |
+---------------------+
| 2010-01-02 00:00:06 |
+---------------------+
1 row in set (0.01 sec)

mysql> exit
Bye

$ mysql -u johndoe -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 16
Server version: 5.7.18

Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> SELECT CURRENT_USER();
ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.

其他感兴趣的信息：

6.2.6 When Privilege Changes Take Effect。

在MySQL中更改变量default_password_lifetime之后是否需要运行flush权限？

2 个答案: