MySQL max_allowed_packet
In which case, try adding one to your my.cnf file;
set-variable=max_allowed_packet=xM
Change ‘x’ to 1 (or increase it if you’re still getting errors)
If you are using the mysql client program, its default max_allowed_packet variable is 16MB. That is also the maximum value before MySQL 4.0. To set a larger value from 4.0 on, start mysql like this:
mysql> mysql –max_allowed_packet=32M
That sets the packet size to 32MB.
The server’s default max_allowed_packet value is 1MB. You can increase this if the server needs to handle big queries (for example, if you are working with big BLOB columns). For example, to set the variable to 16MB, start the server like this:
mysql> mysqld –max_allowed_packet=16M
Before MySQL 4.0, use this syntax instead:
mysql> mysqld –set-variable=max_allowed_packet=16M
You can also use an option file to set max_allowed_packet. For example, to set the size for the server to 16MB, add the following lines in an option file:
[mysqld]
max_allowed_packet=16M
Before MySQL 4.0, use this syntax instead:
[mysqld]
set-variable = max_allowed_packet=16M
It’s safe to increase the value of this variable because the extra memory is allocated only when needed. For example, mysqld allocates more memory only when you issue a long query or when mysqld must return a large result row. The small default value of the variable is a precaution to catch incorrect packets between the client and server and also to ensure that you don’t run out of memory by using large packets accidentally.
You can also get strange problems with large packets if you are using large BLOB values but have not given mysqld access to enough memory to handle the query. If you suspect this is the case, try adding ulimit -d 256000 to the beginning of the mysqld_safe script and restarting mysqld.
The max_allowed_packet option specifies how large your MySQL Query/Data Packet can be, and NOT the Maximum File Size that MySQL can maintain. MySQL can theoretically handle database files upto 1 Terrabyte in size.
