How do I increase the `max_allowed_packet` size in MySQL?

Finding and Adjusting max_allowed_packet Metadata in MySQL

Encountering the error "Got a packet bigger than 'max_allowed_packet' bytes" in MySQL indicates that you've reached the limit set for the size of data packets transferred between the client and the server. This variable controls the maximum size of a single data packet that can be sent or received.

To check the current value of the max_allowed_packet variable, run the following command:

SHOW VARIABLES LIKE 'max_allowed_packet';

The default maximum allowed packet size is usually set to 4MB. If you need to increase the packet size to handle larger data transmissions, you can modify the MySQL configuration file.

Finding the MySQL Config File

The MySQL configuration file, typically named my.cnf or my.ini, is located in different directories depending on your operating system:

• Windows: C:ProgramDataMySQLmy.ini
• Linux: /etc/mysql/my.cnf

Setting max_allowed_packet in the Config File

To change the max_allowed_packet size, add or edit the following line in the [mysqld] section of your my.cnf file:

max_allowed_packet=<new size>

For example, to set the maximum allowed packet size to 16MB, you would add the following line:

max_allowed_packet=16M

Applying the Changes

After making the changes, restart the MySQL service to apply them:

• Windows: net stop mysql && net start mysql
• Linux: service mysql restart

Once the server has been restarted, you can verify the new setting using the SHOW VARIABLES command again.

Additional Notes

• Changing the max_allowed_packet value may require adjusting other MySQL settings, such as innodb_log_file_size and thread_stack.
• This change requires access to the MySQL configuration file, which may not be available on shared hosting environments.
• The setting is only applied to the current MySQL instance, and it will not persist across restarts or upgrades. To make the change permanent, it should be added to the system-wide MySQL configuration file.

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