MySQL Bugs: #32543: ERROR 2006 (HY000) at line 40: MySQL server has gone away

Bug #32543	ERROR 2006 (HY000) at line 40: MySQL server has gone away
Submitted:	20 Nov 2007 19:35	Modified:	12 Dec 2007 12:44
Reporter:	Dmitry Labutin	Email Updates:
Status:	Not a Bug	Impact on me:	None
Category:	MySQL Server: General	Severity:	S3 (Non-critical)
Version:	5.0.45-community	OS:	Windows (2003 Server)
Assigned to:	Martin Hansson	CPU Architecture:	Any
Tags:	hy000, server has gone away

Description:
I try move tables from MySQL 4 to MySQL5.
I made backup using mysqldump
Then I try to restore database on MySQL 5 and see:
ERROR 2006 (HY000) at line 40: MySQL server has gone away

How to repeat:
Try to restore table using mysql command

I can't to make file smaller than 500K :(
You can download it here:
http://tmp.incub.ru/mysqlbug/parts2.rar (3 MB)

Thank you for the bug report. Starting the server with the default variables
the server running on Linux gives the correct error message and the Windows
server instead the message reported:

On Linux:

[miguel@skybr 5.0]$ bin/mysql -uroot test
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.0.52-debug Source distribution

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql> source /home/miguel/var/parts2.sql
Query OK, 0 rows affected (0.13 sec)

<cut>

Query OK, 0 rows affected (0.00 sec)

ERROR 1153 (08S01): Got a packet bigger than 'max_allowed_packet' bytes
Query OK, 0 rows affected (0.00 sec)

Query OK, 0 rows affected (0.00 sec)

On Windows:

c:\dev>5.0\bin\mysql -uroot test
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.0.52-nt Source distribution

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql> source c:/temp/parts2.sql
Query OK, 0 rows affected (0.00 sec)

<cut>

Query OK, 0 rows affected (0.00 sec)

ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id:    2
Current database: test

ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id:    3
Current database: test

ERROR 2006 (HY000): MySQL server has gone away
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id:    4
Current database: test

I get the same message, but the server does not die.

echo "select version()" | client/debug/mysql.exe -u root --port=9306 bug32543 
version()
5.0.45-debug-log

client/debug/mysql.exe -u root --port=9306 bug32543 < ../parts2.sql
ERROR 2006 (HY000) at line 40: MySQL server has gone away

echo "select version()" | client/debug/mysql.exe -u root --port=9306 bug32543
version()
5.0.45-debug-log

echo "show tables" | client/debug/mysql.exe -u root --port=9306 bug32543
Tables_in_bug32543
vsm_attachments

Not repeatable on mysql-5.0.45-community with debug build

From the MySQL Manual:

"You can also get these errors ["MySQL server has gone away", my note] if you send a query to the server that is incorrect or too large. If mysqld receives 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 setting the server's max_allowed_packet variable, which has a default value of 1MB. You may also need to increase the maximum packet size on the client end. More information on setting the packet size is given in Section B.1.2.10, “Packet too large”."

From Section B.1.2.10:

"When a MySQL client or the mysqld server receives a packet bigger than max_allowed_packet bytes, it issues a Packet too large error and closes the connection. With some clients, you may also get a Lost connection to MySQL server during query error if the communication packet is too large."

Miguel, can you confirm that the server indeed died when you verified? In that case I haven't managed to repeat it completely.

Martin,
The server didn't died, just the incorrect message.

Thank you, Miguel. In that case there is nothing unexpected happening here.

This is normal behavior in MySQL. The Blob you are trying to insert is bigger than  the maximum packet size. Please refer to secions B.1.2.9 and B.1.2.10 in the manual.

Hi Martin,

I don' agree with the status !bug even you can find in the Manual comments
which may support that conclusion. The question is why on Linux is launched
the actual error message:

ERROR 1153 (08S01): Got a packet bigger than 'max_allowed_packet' bytes
Query OK, 0 rows affected (0.00 sec)

which indicates to the user where he can fix the issue. On another hand Windows
server gives an error messages that sometimes is launched when the server
actually was away:

ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id:    2
Current database: test

So my question: why Linux and Windows servers behaves different in the error
message. Thanks in advance.

I believe this is still the case in 5.5.11, can't tell for sure as I don't have anyway of finding out if this was the error.

Which seems like the reason this bug was raised, so the user knows what the error was when running under windows.

I would hence, kindly request this bug is reopened so it can be fixed.

I agree with Steven, it would be really nice if this would be fixed.