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(mysql.info)Gone away

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`MySQL server has gone away' Error
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This section also covers the related `Lost connection to server during
query' error.

The most common reason for the `MySQL server has gone away' error is
that the server timed out and closed the connection. By default, the
server closes the connection after 8 hours if nothing has happened. You
can change the time limit by setting the `wait_timeout' variable when
you start `mysqld'.

Another common reason to receive the `MySQL server has gone away' error
is because you have issued a "close" on your MySQL connection and then
tried to run a query on the closed connection.

You can check that the MySQL hasn't died by executing `mysqladmin
version' and examining the uptime.

If you have a script, you just have to issue the query again for the
client to do an automatic reconnection.

You normally can get the following error codes in this case (which one
you get is OS-dependent):

`CR_SERVER_GONE_ERROR' The client couldn't send a question to the server.
`CR_SERVER_LOST'       The client didn't get an error when writing to
                       the server, but it didn't get a full answer (or
                       any answer) to the question.

You can also get these errors if you send a query to the server that is
incorrect or too large. If `mysqld' gets a packet that is too large or
out of order, it assumes that something has gone wrong with the client
and closes the connection.  If you need big queries (for example, if
you are working with big `BLOB' columns), you can increase the query
limit by starting `mysqld' with the `-O max_allowed_packet=#' option
(default 1M). The extra memory is allocated on demand, so `mysqld' will
use more memory only when you issue a big query or when `mysqld' must
return a big result row!