欢迎访问 生活随笔！
TAG聚合

生活随笔

当前位置： 首页 > 编程资源 > 编程问答 >内容正文

编程问答

How to change max_allowed_packet size

发布时间：2023/12/10 编程问答 40 豆豆
生活随笔 收集整理的这篇文章主要介绍了 How to change max_allowed_packet size 小编觉得挺不错的,现在分享给大家,帮大家做个参考.

2019独角兽企业重金招聘Python工程师标准>>>

How to change max_allowed_packet size

up vote        116        down vote        favorite        

40

I am having a problem with BLOB fields in my MySQL database - when uploading files larger than approx 1MB I get an error Packets larger than max_allowed_packet are not allowed.

Here is what i've tried:

In MySQL Query Browser I ran a show variables like 'max_allowed_packet' which gave me 1048576.

Then I execute the query set global max_allowed_packet=33554432 followed by show variables like 'max_allowed_packet' - it gives me 33554432 as expected.

But when I restart the MySQL server it magically goes back to 1048576. What am I doing wrong here?

Bonus question, is it possible to compress a BLOB field?

mysql    

shareimprove this question

asked Nov 9 '11 at 9:01    

   

Muleskinner        

3,891123868        



A BLOB field is a Binary Large OBject. It's just bits. So yes, you can compress the contents, and it gives other (and hopefully, less) bits you store in the BLOB-field instead. It just changes which data you put in it. You'll have to decompress the BLOB-contents when you need it again, too.                    – Konerak                Nov 9 '11 at 9:12                                                                            



Ok thanks, had hoped a compress feature build into mysql existed                    – Muleskinner                Nov 9 '11 at 9:26                                                                            

1                        

possible duplicate of MySQL Error 1153 - Got a packet bigger than 'max_allowed_packet' bytes                    – cnst                Jan 17 '14 at 4:04                                                                            

add a comment                    

8 Answers

           active                    oldest                    votes

   

up vote        140        down vote        accepted

Change in the my.ini file. Include the single line under [mysqld] in your file

max_allowed_packet=500M

now restart the MySQL service and you are done.

See the documentation for further information.

shareimprove this answer

edited Jan 28 '15 at 14:23    

answered Nov 9 '11 at 9:04    

   

Manuel        

5,31242651        

43                        

Most stuff is easy to find through Google, once you know how and where to find it. Taunting is not needed, but if you could provide a link to the correct location in the MySQL documentation, the user gets to know the official sites and resources and can find it for himself easier the next time. Teach a man to fish...                    – Konerak                Nov 9 '11 at 9:13                                                                                                



Thanks seems to be working even though I had hoped this would be possible without having to modify ini files manually.                    – Muleskinner                Nov 9 '11 at 9:24                                                                            



Changing the my.ini file is basically the same as chaning the settings in other programs. Here it's just a file from which the program reads the info.                    – Manuel                Nov 9 '11 at 9:30                                                                            

13                        

FYI readers, this is also the solution to "MySQL has gone away" error                    – djb                Jul 10 '13 at 14:59                                                                            

1                        

@Konerak, Who was the taunter?                    – Pacerier                Apr 1 '15 at 5:21                                                                                                

show 3 more comments        

up vote        86        down vote

The max_allowed_packet variable can be set globally by running a query.

However, if you do not change it in the my.ini file (as dragon112 suggested), the value will reset when the server restarts, even if you set it globally.

To change the setting for everyone until the server restarts:

SET GLOBAL max_allowed_packet=1073741824;

   

shareimprove this answer

edited May 5 '13 at 21:40    

answered Nov 9 '11 at 9:41    

   

TehShrike        

5,4312025        

3                        

Not helps :(. It displays "Query OK, 0 rows affected (0.00 sec)"                    – artnikpro                Jul 3 '14 at 16:06                                                                                                

5                        

@artnikpro It does work, "Query OK, 0 rows affected (0.00 sec)" might feel misleading but it is right.                    – AnnTea                Aug 4 '14 at 12:09                                                                            

4                        

doesn't work for me. SHOW VARIABLES WHERE variable_name = 'max_allowed_packet' still shows old value                    – Poma                May 22 '15 at 22:47                                                                            

6                        

It shows the old value because max_allowed_packet doesn't change for existing connections.  If you disconnect and reconnect you'll see the updated value.                    – Matt Crinklaw-Vogt                Jul 29 '15 at 20:51                                                                                                



!!! This solution does not work.!!!                    – Pat R Ellery                Aug 17 '15 at 22:00                                                                            

show 1 more comment        

up vote        37        down vote

One of my junior developers was having a problem modifying this for me so I thought I would expand this in greater detail for linux users:

1) open terminal

2) ssh root@YOURIP

3) enter root password

4) nano /etc/my.cnf  (if command is not recognized do this first or try vi then repeat: yum install nano )

5) add the line: max_allowed_packet=256M (obviously adjust size for whatever you need) under the [MYSQLD] section. He made a mistake of putting it at the bottom of the file first so it did not work.

6) Control + O (save)  then ENTER (confirm) then Control + X (exit file)

7) service mysqld restart

8) You can check the change in the variables section on phpmyadmin

shareimprove this answer

answered Jan 20 '14 at 14:32    

   

naw103        

866610        

10                        

-1 for recommending to ssh as root. Root ssh access must be disabled on a safe server. Use sudo instead.                    – tamasd                Jun 4 '14 at 8:55                                                                            



this was actually done on CentosOS6 , I of course agree about not using root ssh access though                    – naw103                Jun 16 '15 at 0:38                                                                                                

add a comment                    

up vote        14        down vote

I think some would also want to know how to find the my.ini file on your PC. For windows users, I think the best way is as follows:

  • Win+R(shortcut for 'run'), type services.msc, Enter

  • You could find an entry like 'MySQL56', right click on it, select properties

  • You could see sth like "D:/Program Files/MySQL/MySQL Server 5.6/bin\mysqld" --defaults-file="D:\ProgramData\MySQL\MySQL Server 5.6\my.ini" MySQL56

    • I got this answer from http://bugs.mysql.com/bug.php?id=68516

    shareimprove this answer

    answered Nov 22 '13 at 3:30    

       

    fstang        

    586510        



    works pefectly thanks                    – Robocide                Jul 1 '15 at 7:43                                                                            



    Excellent!!! Been searching all over for the file...                    – Ayodeji                Jan 22 at 16:34                                                                            

    add a comment                    

    up vote        7        down vote

    If getting this error while performing a backup, max_allowed_packet can be set in the my.cnf particularly for mysqldump.

    [mysqldump]max_allowed_packet=512M

    I kept getting this error while performing a mysqldump and I did not understand because I had this set in my.cnf under the [mysqld] section. Once I figured out I could set it for [mysqldump] and I set the value, my backups completed without issue.

    shareimprove this answer

    edited May 19 '14 at 17:52    

    answered Feb 23 '14 at 21:14    

       

    xpros        

    74979        

    add a comment                    

    up vote        4        down vote

    For those running wamp mysql server

    Wamp tray Icon -> MySql -> my.ini

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

    Scroll down to the end until u find

    [mysqld]port=3306explicit_defaults_for_timestamp = TRUE

    Add the line of packet_size in between

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

    Check whether it worked with this query

    Select @@global.max_allowed_packet;

       

    shareimprove this answer

    answered Sep 29 '15 at 9:38    

       

    Sayka        

    1,9781919        



    plus 1 for mentioning how to check that it is set                    – Abimbola Esuruoso                Dec 27 '15 at 18:18                                                                            

    add a comment                    

    up vote        3        down vote

    This error come because of your data contain larger then set value.

    Just write down the max_allowed_packed=500Mor you can calculate that 500*1024k and use that instead of 500M if you want.

    Now just restart the MySQL.

    shareimprove this answer

    edited Nov 10 '11 at 4:03    

       

    Brock Adams        

    47.3k985138        

    answered Nov 9 '11 at 9:23    

       

    Suresh        

    7372512        



    Where should it be added ????????                    – Pratik C Joshi                Oct 17 '15 at 4:29                                                                            

    add a comment                    

                           

    up vote        0        down vote

    If you want upload big size image or data in database. Just change the data type to 'BIG BLOB'


    转载于:https://my.oschina.net/airship/blog/611190

    创作挑战赛新人创作奖励来咯，坚持创作打卡瓜分现金大奖

    总结

    以上是生活随笔为你收集整理的How to change max_allowed_packet size的全部内容，希望文章能够帮你解决所遇到的问题。

    如果觉得生活随笔网站内容还不错，欢迎将生活随笔推荐给好友。