MySQL Max_allowed_packet Settings and issues

MySQL restricts the size of packets accepted by the server according to the configuration file.

Sometimes large inserts and updates are limited by the Max_allowed_packet parameter, resulting in failure.

View current configuration

Show VARIABLES like '%max_allowed_packet% ';

The results shown are:

The above description is currently configured to: 1M

Modify method

1) Method 1

You can edit the my.cnf to modify (under Windows My.ini) and modify it in the [Mysqld] section or in the MySQL server configuration section.

Max_allowed_packet = 20M

If you can't find the MY.CNF, you can pass

MySQL--help | grep my.cnf

To find the my.cnf file.

2) Method 2

Go to MySQL server

Run in the MySQL command line

Set Global Max_allowed_packet = 2*1024*1024*10

Then shut down this MySQL server link and then enter.

Show VARIABLES like '%max_allowed_packet% ';

See if the next Max_allowed_packet is edited successfully

Experience Summary:

There are no problems with using methods on many machines, but the November 14, 2011 encounter with a machine is not successful anyway.

Using the command line: Set global max_allowed_packet = 16M;

No, but using

Set global max_allowed_packet = 2*1024*1024*10;

Success, it's depressing.

The problem is finally found, not the problem of the method, is the setup after the command line to exit the login to view, it appears that the value of the system variable is cached after login. However, the use of the configuration INI file on this machine is not possible, the specific reason has not been found.

MySQL Max_allowed_packet Settings and issues