如何更改max_allowed_pa​​cket大小

Question

我的MySQL数据库中的BLOB字段有问题 - 当上传大于1MB的文件时,我收到错误 Packets larger than max_allowed_packet are not allowed.

这是我尝试过的:

在MySQL查询浏览器中,我跑了一个show variables like 'max_allowed_packet'给了我1048576.

然后我执行查询set global max_allowed_packet=33554432后跟show variables like 'max_allowed_packet'- 它按预期给我33554432.

但是当我重新启动MySQL服务器时,它神奇地回到了1048576.我在这里做错了什么？

奖金问题,是否可以压缩BLOB字段？

Answer 1

通过在文件的下方或部分中包含单行更改my.ini或文件:~/.my.cnf[mysqld][client]

max_allowed_packet=500M

然后重新启动MySQL服务,你就完成了.

有关详细信息,请参阅文档.

Answer 2

该max_allowed_pa​​cket的变量可以在全球范围通过运行查询进行设置.

但是,如果您不在my.ini文件中更改它(如建议的dragon112),则在服务器重新启动时,该值将重置,即使您全局设置它也是如此.

要将每个人的最大允许数据包更改为1GB,直到服务器重新启动:

SET GLOBAL max_allowed_packet=1073741824;

Answer 3

我的一个初级开发人员在为我修改这个问题时遇到了问题所以我想我会为linux用户更详细地扩展它:

1)开放终端

2)ssh root @ YOURIP

3)输入root密码

4)纳米/etc/mysql/my.cnf(如果命令不被识别为此,首先还是尽量VI然后重复:百胜安装纳米)

5)在[MYSQLD]部分下添加行:max_allowed_pa​​cket = 256M(显然可以根据需要调整大小).他错误地把它放在文件的底部,所以它不起作用.

6)Control + O(保存)然后按ENTER(确认)然后按Control + X(退出文件)

7)服务mysqld重启

8)您可以在phpmyadmin上检查变量部分的更改

Answer 4

我想有些人还想知道如何在PC上找到my.ini文件.对于Windows用户,我认为最好的方法如下:

1. Win + R("运行"的快捷方式),键入services.msc,回车
2. 你可以找到像'MySQL56'这样的条目,右键单击它,选择属性
3. 你可以看到像"D:/ Program Files/MySQL/MySQL Server 5.6/bin\mysqld"--defaults-file ="D:\ ProgramData\MySQL\MySQL Server 5.6\my.ini"MySQL56

我从http://bugs.mysql.com/bug.php?id=68516得到了这个答案

Answer 5

按照所有说明,这就是我所做的和工作:

mysql> SELECT CONNECTION_ID();//This is my ID for this session.
+-----------------+
| CONNECTION_ID() |
+-----------------+
|              20 |
+-----------------+
1 row in set (0.00 sec)

mysql> select @max_allowed_packet //Mysql do not found @max_allowed_packet
+---------------------+
| @max_allowed_packet |
+---------------------+
| NULL                |
+---------------------+
1 row in set (0.00 sec)

mysql> Select @@global.max_allowed_packet; //That is better... I have max_allowed_packet=32M inside my.ini
+-----------------------------+
| @@global.max_allowed_packet |
+-----------------------------+
|                    33554432 |
+-----------------------------+
1 row in set (0.00 sec)

mysql> **SET GLOBAL max_allowed_packet=1073741824**; //Now I'm changing the value.
Query OK, 0 rows affected (0.00 sec)

mysql> select @max_allowed_packet; //Mysql not found @max_allowed_packet
+---------------------+
| @max_allowed_packet |
+---------------------+
| NULL                |
+---------------------+
1 row in set (0.00 sec)

mysql> Select @@global.max_allowed_packet;//The new value. And I still have max_allowed_packet=32M inisde my.ini
+-----------------------------+
| @@global.max_allowed_packet |
+-----------------------------+
|                  1073741824 |
+-----------------------------+
1 row in set (0.00 sec)

因此,正如我们所看到的,max_allowed_pa​​cket已在my.ini之外进行了更改.

让我们离开会话并再次检查:

mysql> exit
Bye

C:\Windows\System32>mysql -uroot -pPassword
Warning: Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 21
Server version: 5.6.26-log MySQL Community Server (GPL)

Copyright (c) 2000, 2015, 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 CONNECTION_ID();//This is my ID for this session.
+-----------------+
| CONNECTION_ID() |
+-----------------+
|              21 |
+-----------------+
1 row in set (0.00 sec)

mysql> Select @@global.max_allowed_packet;//The new value still here and And I still have max_allowed_packet=32M inisde my.ini
+-----------------------------+
| @@global.max_allowed_packet |
+-----------------------------+
|                  1073741824 |
+-----------------------------+
1 row in set (0.00 sec)

Now I will stop the server
2016-02-03 10:28:30 - Server is stopped

mysql> SELECT CONNECTION_ID();
ERROR 2013 (HY000): Lost connection to MySQL server during query


Now I will start the server
2016-02-03 10:31:54 - Server is running


C:\Windows\System32>mysql -uroot -pPassword
Warning: Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 9
Server version: 5.6.26-log MySQL Community Server (GPL)

Copyright (c) 2000, 2015, 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 CONNECTION_ID();
+-----------------+
| CONNECTION_ID() |
+-----------------+
|               9 |
+-----------------+
1 row in set (0.00 sec)

mysql> Select @@global.max_allowed_packet;//The previous new value has gone. Now I see what I have inside my.ini again.
+-----------------------------+
| @@global.max_allowed_packet |
+-----------------------------+
|                    33554432 |
+-----------------------------+
1 row in set (0.00 sec)

结论,在SET GLOBAL max_allowed_pa​​cket = 1073741824之后,服务器将拥有新的max_allowed_pa​​cket,直到它重新启动,如前所述.

Answer 6

如果在执行备份时出现此错误,max_allowed_packet可以在my.cnf特别设置中进行设置mysqldump.

[mysqldump]
max_allowed_packet=512M

我在执行a时一直遇到这个错误mysqldump而且我不理解因为我在这个部分my.cnf下面有这个设置[mysqld].一旦我弄清楚我可以设置它[mysqldump]并设置值,我的备份完成没有问题.

Answer 7

对于那些运行wamp mysql服务器的人

Wamp托盘图标 - > MySql - > my.ini

[wampmysqld]
port        = 3306
socket      = /tmp/mysql.sock
key_buffer_size = 16M
max_allowed_packet = 16M        // --> changing this wont solve
sort_buffer_size = 512K

向下滚动直到找到

[mysqld]
port=3306
explicit_defaults_for_timestamp = TRUE

在其间添加packet_size行

[mysqld]
port=3306
max_allowed_packet = 16M
explicit_defaults_for_timestamp = TRUE

检查它是否适用于此查询

Select @@global.max_allowed_packet;

Answer 8

出现此错误是因为您的数据包含大于设置的值。

只需记下max_allowed_packed=500M 或您可以计算出 500*1024k，并根据需要使用它而不是 500M。

现在只需重新启动MySQL。

Answer 9

许多回答者发现了问题并已经给出了解决方案。

我只想建议另一个解决方案，它是从Mysql Workbench工具中更改Glogal变量值。当然，如果您使用在服务器上本地运行的Workbench（或通过SSH连接）

您只需连接到实例并进入菜单：

服务器->选项文件->网络-> max_allowed_pa​​cked

您设置所需的值，然后需要重新启动MySql Service。

Answer 10

对于在 Amazon RDS 服务上运行 MySQL 的任何人，此更改是通过参数组完成的。您需要创建一个新的 PG 或使用现有的 PG（默认值除外，默认值是只读的）。

您应该搜索max_allowed_packet参数，更改其值，然后单击“保存”。

回到您的 MySQL 实例，如果您创建了一个新的 PG，您应该将该 PG 附加到您的实例（您可能需要重新启动）。如果您更改了已附加到实例的 PG，则更改将应用​​到附加了该 PG 的所有实例，无需重新启动。