MySQL Bugs: #9752: ERROR 2013 (HY000): Lost connection to MySQL server during query

Bug #9752	ERROR 2013 (HY000): Lost connection to MySQL server during query
Submitted:	8 Apr 2005 10:58	Modified:	1 Jul 2005 14:12
Reporter:	[ name withheld ] (Basic Quality Contributor)	Email Updates:
Status:	Can't repeat	Impact on me:	None
Category:	MySQL Server: Command-line Clients	Severity:	S2 (Serious)
Version:	5.0.3	OS:	Windows (Windows XP sp1)
Assigned to:		CPU Architecture:	Any

Description:
While trying to run the Mondrian Foodmart data sql file (mondrian.sourceforge.net) which is 26.793.842 byte of size I get this error immediately after hitting Return key:

C:\>mysql -uuser -ppassword < c:\foodmart.sql
ERROR 2013 (HY000): Lost connection to MySQL server during query

C:\>

In my.ini I have already set:

# maximum packet size
max_allowed_packet=64M

How to repeat:
Download the data set from http://sf.gds.tuwien.ac.at/00-cat/dri/mondrian/mondrian-data-mysql.zip and then try to load it as above.

The OS is Windows XP sp1, previously I mentioned sp2, sorry

I get this when running scripts with multiline commands.

Single line commands seem to work fine, but limited in command size.
I am running Windows XP Professional SP2.
The port is 3307.
I have to manually restart the service since it has stopped.

# MySQL Server Instance Configuration File
# ----------------------------------------------------------------------
# Generated by the MySQL Server Instance Configuration Wizard
#
#
# Installation Instructions
# ----------------------------------------------------------------------
#
# On Linux you can copy this file to /etc/my.cnf to set global options,
# mysql-data-dir/my.cnf to set server-specific options
# (@localstatedir@ for this installation) or to
# ~/.my.cnf to set user-specific options.
#
# On Windows you should keep this file in the installation directory
# of your server (e.g. C:\Program Files\MySQL\MySQL Server 4.1). To
# make sure the server reads the config file use the startup option
# "--defaults-file".
#
# To run run the server from the command line, execute this in a
# command line shell, e.g.
# mysqld --defaults-file="C:\Program Files\MySQL\MySQL Server 4.1\my.ini"
#
# To install the server as a Windows service manually, execute this in a
# command line shell, e.g.
# mysqld --install MySQL41 --defaults-file="C:\Program Files\MySQL\MySQL Server 4.1\my.ini"
#
# And then execute this in a command line shell to start the server, e.g.
# net start MySQL41
#
#
# Guildlines for editing this file
# ----------------------------------------------------------------------
#
# In this file, you can use all long options that the program supports.
# If you want to know the options a program supports, start the program
# with the "--help" option.
#
# More detailed information about the individual options can also be
# found in the manual.
#
#
# CLIENT SECTION
# ----------------------------------------------------------------------
#
# The following options will be read by MySQL client applications.
# Note that only client applications shipped by MySQL are guaranteed
# to read this section. If you want your own MySQL client program to
# honor these values, you need to specify it as an option during the
# MySQL client library initialization.
#
[client]

port=3307

# SERVER SECTION
# ----------------------------------------------------------------------
#
# The following options will be read by the MySQL Server. Make sure that
# you have installed the server correctly (see above) so it reads this
# file.
#
[mysqld]

# The TCP/IP Port the MySQL Server will listen on
port=3307

#Path to installation directory. All paths are usually resolved relative to this.
basedir="C:/Program Files/MySQL/MySQL Server 5.0/"

#Path to the database root
datadir="C:/Program Files/MySQL/MySQL Server 5.0/Data/"

# The default character set that will be used when a new schema or table is
# created and no character set is defined
default-character-set=utf8

# The default storage engine that will be used when create new tables when
default-storage-engine=INNODB

# The maximum amount of concurrent sessions the MySQL server will
# allow. One of these connections will be reserved for a user with
# SUPER privileges to allow the administrator to login even if the
# connection limit has been reached.
max_connections=100

# Query cache is used to cache SELECT results and later return them
# without actual executing the same query once again. Having the query
# cache enabled may result in significant speed improvements, if your
# have a lot of identical queries and rarely changing tables. See the
# "Qcache_lowmem_prunes" status variable to check if the current value
# is high enough for your load.
# Note: In case your tables change very often or if your queries are
# textually different every time, the query cache may result in a
# slowdown instead of a performance improvement.
query_cache_size=0

# The number of open tables for all threads. Increasing this value
# increases the number of file descriptors that mysqld requires.
# Therefore you have to make sure to set the amount of open files
# allowed to at least 4096 in the variable "open-files-limit" in
# section [mysqld_safe]
table_cache=256

# Maximum size for internal (in-memory) temporary tables. If a table
# grows larger than this value, it is automatically converted to disk
# based table This limitation is for a single table. There can be many
# of them.
tmp_table_size=9M

# How many threads we should keep in a cache for reuse. When a client
# disconnects, the client's threads are put in the cache if there aren't
# more than thread_cache_size threads from before. This greatly reduces
# the amount of thread creations needed if you have a lot of new
# connections. (Normally this doesn't give a notable performance
# improvement if you have a good thread implementation.)
thread_cache_size=8

#*** MyISAM Specific options

# The maximum size of the temporary file MySQL is allowed to use while
# recreating the index (during REPAIR, ALTER TABLE or LOAD DATA INFILE.
# If the file-size would be bigger than this, the index will be created
# through the key cache (which is slower).
myisam_max_sort_file_size=100G

# If the temporary file used for fast index creation would be bigger
# than using the key cache by the amount specified here, then prefer the
# key cache method. This is mainly used to force long character keys in
# large tables to use the slower key cache method to create the index.
myisam_max_extra_sort_file_size=100G

# Size of the Key Buffer, used to cache index blocks for MyISAM tables.
# Do not set it larger than 30% of your available memory, as some memory
# is also required by the OS to cache rows. Even if you're not using
# MyISAM tables, you should still set it to 8-64M as it will also be
# used for internal temporary disk tables.
key_buffer_size=11M

# Size of the buffer used for doing full table scans of MyISAM tables.
# Allocated per thread, if a full scan is needed.
read_buffer_size=64K
read_rnd_buffer_size=256K

# This buffer is allocated when MySQL needs to rebuild the index in
# REPAIR, OPTIMZE, ALTER table statements as well as in LOAD DATA INFILE
# into an empty table. It is allocated per thread so be careful with
# large settings.
sort_buffer_size=256K

#*** INNODB Specific options ***

# Use this option if you have a MySQL server with InnoDB support enabled
# but you do not plan to use it. This will save memory and disk space
# and speed up some things.
#skip-innodb

# Additional memory pool that is used by InnoDB to store metadata
# information. If InnoDB requires more memory for this purpose it will
# start to allocate it from the OS. As this is fast enough on most
# recent operating systems, you normally do not need to change this
# value. SHOW INNODB STATUS will display the current amount used.
innodb_additional_mem_pool_size=2M

# If set to 1, InnoDB will flush (fsync) the transaction logs to the
# disk at each commit, which offers full ACID behavior. If you are
# willing to compromise this safety, and you are running small
# transactions, you may set this to 0 or 2 to reduce disk I/O to the
# logs. Value 0 means that the log is only written to the log file and
# the log file flushed to disk approximately once per second. Value 2
# means the log is written to the log file at each commit, but the log
# file is only flushed to disk approximately once per second.
innodb_flush_log_at_trx_commit=1

# The size of the buffer InnoDB uses for buffering log data. As soon as
# it is full, InnoDB will have to flush it to disk. As it is flushed
# once per second anyway, it does not make sense to have it very large
# (even with long transactions).
innodb_log_buffer_size=1M

# InnoDB, unlike MyISAM, uses a buffer pool to cache both indexes and
# row data. The bigger you set this the less disk I/O is needed to
# access data in tables. On a dedicated database server you may set this
# parameter up to 80% of the machine physical memory size. Do not set it
# too large, though, because competition of the physical memory may
# cause paging in the operating system. Note that on 32bit systems you
# might be limited to 2-3.5G of user level memory per process, so do not
# set it too high.
innodb_buffer_pool_size=18M

# Size of each log file in a log group. You should set the combined size
# of log files to about 25%-100% of your buffer pool size to avoid
# unneeded buffer pool flush activity on log file overwrite. However,
# note that a larger logfile size will increase the time needed for the
# recovery process.
innodb_log_file_size=10M

# Number of threads allowed inside the InnoDB kernel. The optimal value
# depends highly on the application, hardware as well as the OS
# scheduler properties. A too high value may lead to thread thrashing.
innodb_thread_concurrency=8

The server crash happens when using CREATE TABLE with ENUM column types.

I have the same problem on Win 2003.  It's incredibly annoying.

After being logged in for a while, I got the same error using the following query:

mysql> select event_id,
    -> min(score),
    -> max(score),
    -> max(score) - min(score) + 1 as range,
    -> sum(score) as total,
    -> avg(score) as average,
    -> count(score) as count
    -> from score
    -> group by event_id
    -> with rollup;
ERROR 2013 (HY000): Lost connection to MySQL server during query

I was querying the following table:

CREATE TABLE score
(
	student_id	INT UNSIGNED NOT NULL,
	event_id	INT UNSIGNED NOT NULL,
	score		INT NOT NULL,
	PRIMARY KEY (event_id, student_id),
	INDEX (student_id),
	FOREIGN KEY (event_id) REFERENCES grade_event (event_id),
	FOREIGN KEY (student_id) REFERENCES student (student_id)
) ENGINE = InnoDB;

score contained the following data:

DELETE FROM score;
INSERT INTO score VALUES (1,1,20);
INSERT INTO score VALUES (3,1,20);
INSERT INTO score VALUES (4,1,18);
INSERT INTO score VALUES (5,1,13);
INSERT INTO score VALUES (6,1,18);
INSERT INTO score VALUES (7,1,14);
INSERT INTO score VALUES (8,1,14);
INSERT INTO score VALUES (9,1,11);
INSERT INTO score VALUES (10,1,19);
INSERT INTO score VALUES (11,1,18);
INSERT INTO score VALUES (12,1,19);
INSERT INTO score VALUES (14,1,11);
INSERT INTO score VALUES (15,1,20);
INSERT INTO score VALUES (16,1,18);
INSERT INTO score VALUES (17,1,9);
INSERT INTO score VALUES (18,1,20);
INSERT INTO score VALUES (19,1,9);
INSERT INTO score VALUES (20,1,9);
INSERT INTO score VALUES (21,1,13);
INSERT INTO score VALUES (22,1,13);
INSERT INTO score VALUES (23,1,16);
INSERT INTO score VALUES (24,1,11);
INSERT INTO score VALUES (25,1,19);
INSERT INTO score VALUES (26,1,10);
INSERT INTO score VALUES (27,1,15);
INSERT INTO score VALUES (28,1,15);
INSERT INTO score VALUES (29,1,19);
INSERT INTO score VALUES (30,1,17);
INSERT INTO score VALUES (31,1,11);
INSERT INTO score VALUES (1,2,17);
INSERT INTO score VALUES (2,2,8);
INSERT INTO score VALUES (3,2,13);
INSERT INTO score VALUES (4,2,13);
INSERT INTO score VALUES (5,2,17);
INSERT INTO score VALUES (6,2,13);
INSERT INTO score VALUES (7,2,17);
INSERT INTO score VALUES (8,2,8);
INSERT INTO score VALUES (9,2,19);
INSERT INTO score VALUES (10,2,18);
INSERT INTO score VALUES (11,2,15);
INSERT INTO score VALUES (12,2,19);
INSERT INTO score VALUES (13,2,18);
INSERT INTO score VALUES (14,2,18);
INSERT INTO score VALUES (15,2,16);
INSERT INTO score VALUES (16,2,9);
INSERT INTO score VALUES (17,2,13);
INSERT INTO score VALUES (18,2,9);
INSERT INTO score VALUES (19,2,11);
INSERT INTO score VALUES (21,2,12);
INSERT INTO score VALUES (22,2,10);
INSERT INTO score VALUES (23,2,17);
INSERT INTO score VALUES (24,2,19);
INSERT INTO score VALUES (25,2,10);
INSERT INTO score VALUES (26,2,18);
INSERT INTO score VALUES (27,2,8);
INSERT INTO score VALUES (28,2,13);
INSERT INTO score VALUES (29,2,16);
INSERT INTO score VALUES (30,2,12);
INSERT INTO score VALUES (31,2,19);
INSERT INTO score VALUES (1,3,88);
INSERT INTO score VALUES (2,3,84);
INSERT INTO score VALUES (3,3,69);
INSERT INTO score VALUES (4,3,71);
INSERT INTO score VALUES (5,3,97);
INSERT INTO score VALUES (6,3,83);
INSERT INTO score VALUES (7,3,88);
INSERT INTO score VALUES (8,3,75);
INSERT INTO score VALUES (9,3,83);
INSERT INTO score VALUES (10,3,72);
INSERT INTO score VALUES (11,3,74);
INSERT INTO score VALUES (12,3,77);
INSERT INTO score VALUES (13,3,67);
INSERT INTO score VALUES (14,3,68);
INSERT INTO score VALUES (15,3,75);
INSERT INTO score VALUES (16,3,60);
INSERT INTO score VALUES (17,3,79);
INSERT INTO score VALUES (18,3,96);
INSERT INTO score VALUES (19,3,79);
INSERT INTO score VALUES (20,3,76);
INSERT INTO score VALUES (21,3,91);
INSERT INTO score VALUES (22,3,81);
INSERT INTO score VALUES (23,3,81);
INSERT INTO score VALUES (24,3,62);
INSERT INTO score VALUES (25,3,79);
INSERT INTO score VALUES (26,3,86);
INSERT INTO score VALUES (27,3,90);
INSERT INTO score VALUES (28,3,68);
INSERT INTO score VALUES (29,3,66);
INSERT INTO score VALUES (30,3,79);
INSERT INTO score VALUES (31,3,81);
INSERT INTO score VALUES (2,4,7);
INSERT INTO score VALUES (3,4,17);
INSERT INTO score VALUES (4,4,16);
INSERT INTO score VALUES (5,4,20);
INSERT INTO score VALUES (6,4,9);
INSERT INTO score VALUES (7,4,19);
INSERT INTO score VALUES (8,4,12);
INSERT INTO score VALUES (9,4,17);
INSERT INTO score VALUES (10,4,12);
INSERT INTO score VALUES (11,4,16);
INSERT INTO score VALUES (12,4,13);
INSERT INTO score VALUES (13,4,8);
INSERT INTO score VALUES (14,4,11);
INSERT INTO score VALUES (15,4,9);
INSERT INTO score VALUES (16,4,20);
INSERT INTO score VALUES (18,4,11);
INSERT INTO score VALUES (19,4,15);
INSERT INTO score VALUES (20,4,17);
INSERT INTO score VALUES (21,4,13);
INSERT INTO score VALUES (22,4,20);
INSERT INTO score VALUES (23,4,13);
INSERT INTO score VALUES (24,4,12);
INSERT INTO score VALUES (25,4,10);
INSERT INTO score VALUES (26,4,15);
INSERT INTO score VALUES (28,4,17);
INSERT INTO score VALUES (30,4,11);
INSERT INTO score VALUES (31,4,19);
INSERT INTO score VALUES (1,5,15);
INSERT INTO score VALUES (2,5,12);
INSERT INTO score VALUES (3,5,11);
INSERT INTO score VALUES (5,5,13);
INSERT INTO score VALUES (6,5,18);
INSERT INTO score VALUES (7,5,14);
INSERT INTO score VALUES (8,5,18);
INSERT INTO score VALUES (9,5,13);
INSERT INTO score VALUES (10,5,14);
INSERT INTO score VALUES (11,5,18);
INSERT INTO score VALUES (12,5,8);
INSERT INTO score VALUES (13,5,8);
INSERT INTO score VALUES (14,5,16);
INSERT INTO score VALUES (15,5,13);
INSERT INTO score VALUES (16,5,15);
INSERT INTO score VALUES (17,5,11);
INSERT INTO score VALUES (18,5,18);
INSERT INTO score VALUES (19,5,18);
INSERT INTO score VALUES (20,5,14);
INSERT INTO score VALUES (21,5,17);
INSERT INTO score VALUES (22,5,17);
INSERT INTO score VALUES (23,5,15);
INSERT INTO score VALUES (25,5,14);
INSERT INTO score VALUES (26,5,8);
INSERT INTO score VALUES (28,5,20);
INSERT INTO score VALUES (29,5,16);
INSERT INTO score VALUES (31,5,9);
INSERT INTO score VALUES (1,6,100);
INSERT INTO score VALUES (2,6,91);
INSERT INTO score VALUES (3,6,94);
INSERT INTO score VALUES (4,6,74);
INSERT INTO score VALUES (5,6,97);
INSERT INTO score VALUES (6,6,89);
INSERT INTO score VALUES (7,6,76);
INSERT INTO score VALUES (8,6,65);
INSERT INTO score VALUES (9,6,73);
INSERT INTO score VALUES (10,6,63);
INSERT INTO score VALUES (11,6,98);
INSERT INTO score VALUES (12,6,75);
INSERT INTO score VALUES (14,6,77);
INSERT INTO score VALUES (15,6,62);
INSERT INTO score VALUES (16,6,98);
INSERT INTO score VALUES (17,6,94);
INSERT INTO score VALUES (18,6,94);
INSERT INTO score VALUES (19,6,74);
INSERT INTO score VALUES (20,6,62);
INSERT INTO score VALUES (21,6,73);
INSERT INTO score VALUES (22,6,95);
INSERT INTO score VALUES (24,6,68);
INSERT INTO score VALUES (25,6,85);
INSERT INTO score VALUES (26,6,91);
INSERT INTO score VALUES (27,6,70);
INSERT INTO score VALUES (28,6,77);
INSERT INTO score VALUES (29,6,66);
INSERT INTO score VALUES (30,6,68);
INSERT INTO score VALUES (31,6,76);

You can download the full sql source, which accompanies the book "MySQL" by Paul DuBois, 3rd ed, here: http://www.kitebird.com/mysql-book/

The error occurred on an IBM Thinkpad T41, running Windows XP Professional, Version 2002, SP 1. Please see the attached ZIP file for a screen shot,

Sorry; I'm not allowed to attach a file to this bug. :$

I removed version 5.0.4b and installed 5.0.7-beta-nt, and the following query worked without generating an error:

mysql> select event_id,
    -> min(score),
    -> max(score),
    -> max(score) - min(score) + 1 as range,
    -> sum(score) as total,
    -> avg(score) as average,
    -> count(score) as count
    -> from score
    -> group by event_id
    -> with rollup;
+----------+------------+------------+-------+-------+---------+-------+
| event_id | min(score) | max(score) | range | total | average | count |
+----------+------------+------------+-------+-------+---------+-------+
|        1 |          9 |         20 |    12 |   439 | 15.1379 |    29 |
|        2 |          8 |         19 |    12 |   425 | 14.1667 |    30 |
|        3 |         60 |         97 |    38 |  2425 | 78.2258 |    31 |
|        4 |          7 |         20 |    14 |   379 | 14.0370 |    27 |
|        5 |          8 |         20 |    13 |   383 | 14.1852 |    27 |
|        6 |         62 |        100 |    39 |  2325 | 80.1724 |    29 |
|     NULL |          7 |        100 |    94 |  6376 | 36.8555 |   173 |
+----------+------------+------------+-------+-------+---------+-------+
7 rows in set (0.06 sec)

mysql> select version();
+---------------+
| version()     |
+---------------+
| 5.0.7-beta-nt |
+---------------+
1 row in set (0.00 sec)

I wasn't able reproduce it with 5.0.7

I had a similar problem and it was resolved by setting the value of the variable query_cache_size=8M

Previously, I had it set to 64K and it would report the ERROR 2013. In the config file that I see above the value is set to 0. So a higher value should definitely solve the problem.

Hope that helps.

Kalpesh.

***** POSSIBLE FIX ********

I had my key_buffer_size set at 8GB.
I changed it to 4GB and this error message went away.
Apparently there is some bug that causes instability when key_buffer_size > 4GB?