#2006 MySQL Server has gone away error in Wamp

问题:

Im using Wampserver version 2.0 . When i try to import a sql file, either through MySQL Query Browser or PHPMyAdmin,i get the following error.

Error 2006: MySQL Server has gone away.

The size of the file is 54,528 KB.

In C:\wamp\bin\mysql\mysql5.1.30\my.ini , i set the max_allowed_packet to 100M in [mysqldump] and [wampmysqld]. I couldnt find wait_timeout variable in my.ini. Any way to fix this problem ?. For your reference, i have given below the contents of my.ini file.

# Example MySQL config file for medium systems.
#
# This is for a system with little memory (32M - 64M) where MySQL plays
# an important part, or systems up to 128M where MySQL is used together with
# other programs (such as a web server)
#
# You can copy this file to
# /etc/my.cnf to set global options,
# mysql-data-dir/my.cnf to set server-specific options (in this
# installation this directory is C:\mysql\data) or
# ~/.my.cnf to set user-specific options.
#
# In this file, you can use all long options that a program supports.
# If you want to know which options a program supports, run the program
# with the "--help" option.

# The following options will be passed to all MySQL clients
[client]
#password   = your_password
port        = 3306
socket      = /tmp/mysql.sock

# Here follows entries for some specific programs

# The MySQL server
[wampmysqld]
port        = 3306
socket      = /tmp/mysql.sock
skip-locking
key_buffer = 16M
max_allowed_packet = 100M
table_cache = 64
sort_buffer_size = 512K
net_buffer_length = 8K
read_buffer_size = 256K
read_rnd_buffer_size = 512K
myisam_sort_buffer_size = 8M
basedir=c:/wamp/bin/mysql/mysql5.1.30
log-error=c:/wamp/logs/mysql.log
datadir=c:/wamp/bin/mysql/mysql5.1.30/data

# Don't listen on a TCP/IP port at all. This can be a security enhancement,
# if all processes that need to connect to mysqld run on the same host.
# All interaction with mysqld must be made via Unix sockets or named pipes.
# Note that using this option without enabling named pipes on Windows
# (via the "enable-named-pipe" option) will render mysqld useless!
# 
#skip-networking

# Disable Federated by default
skip-federated

# Replication Master Server (default)
# binary logging is required for replication
log-bin=mysql-bin

# binary logging format - mixed recommended
binlog_format=mixed

# required unique id between 1 and 2^32 - 1
# defaults to 1 if master-host is not set
# but will not function as a master if omitted
server-id   = 1

# Replication Slave (comment out master section to use this)
#
# To configure this host as a replication slave, you can choose between
# two methods :
#
# 1) Use the CHANGE MASTER TO command (fully described in our manual) -
#    the syntax is:
#
#    CHANGE MASTER TO MASTER_HOST=<host>, MASTER_PORT=<port>,
#    MASTER_USER=<user>, MASTER_PASSWORD=<password> ;
#
#    where you replace <host>, <user>, <password> by quoted strings and
#    <port> by the master's port number (3306 by default).
#
#    Example:
#
#    CHANGE MASTER TO MASTER_HOST='125.564.12.1', MASTER_PORT=3306,
#    MASTER_USER='joe', MASTER_PASSWORD='secret';
#
# OR
#
# 2) Set the variables below. However, in case you choose this method, then
#    start replication for the first time (even unsuccessfully, for example
#    if you mistyped the password in master-password and the slave fails to
#    connect), the slave will create a master.info file, and any later
#    change in this file to the variables' values below will be ignored and
#    overridden by the content of the master.info file, unless you shutdown
#    the slave server, delete master.info and restart the slaver server.
#    For that reason, you may want to leave the lines below untouched
#    (commented) and instead use CHANGE MASTER TO (see above)
#
# required unique id between 2 and 2^32 - 1
# (and different from the master)
# defaults to 2 if master-host is set
# but will not function as a slave if omitted
#server-id       = 2
#
# The replication master for this slave - required
#master-host     =   <hostname>
#
# The username the slave will use for authentication when connecting
# to the master - required
#master-user     =   <username>
#
# The password the slave will authenticate with when connecting to
# the master - required
#master-password =   <password>
#
# The port the master is listening on.
# optional - defaults to 3306
#master-port     =  <port>
#
# binary logging - not required for slaves, but recommended
#log-bin=mysql-bin

# Point the following paths to different dedicated disks
#tmpdir     = /tmp/     
#log-update     = /path-to-dedicated-directory/hostname

# Uncomment the following if you are using InnoDB tables
#innodb_data_home_dir = C:\mysql\data/
#innodb_data_file_path = ibdata1:10M:autoextend
#innodb_log_group_home_dir = C:\mysql\data/
#innodb_log_arch_dir = C:\mysql\data/
# You can set .._buffer_pool_size up to 50 - 80 %
# of RAM but beware of setting memory usage too high
#innodb_buffer_pool_size = 16M
#innodb_additional_mem_pool_size = 2M
# Set .._log_file_size to 25 % of buffer pool size
#innodb_log_file_size = 5M
#innodb_log_buffer_size = 8M
#innodb_flush_log_at_trx_commit = 1
#innodb_lock_wait_timeout = 50

[mysqldump]
quick
max_allowed_packet = 100M

[mysql]
no-auto-rehash
# Remove the next comment character if you are not familiar with SQL
#safe-updates

[isamchk]
key_buffer = 20M
sort_buffer_size = 20M
read_buffer = 2M
write_buffer = 2M

[myisamchk]
key_buffer = 20M
sort_buffer_size = 20M
read_buffer = 2M
write_buffer = 2M

[mysqlhotcopy]
interactive-timeout

[mysqld]
port=3306

回答1:

I'm using XAMPP on Windows and had the same problem. I thought it was the timeout variable but it was max_allowed_packet.

This has fixed it:

# note the change was made at this section
[mysqld] 
port= 3306
socket= "/xampp/mysql/mysql.sock"
basedir="/xampp/mysql" 
tmpdir="/xampp/tmp" 
datadir="/xampp/mysql/data"
skip-locking
key_buffer = 16M
# it was 1M by default
max_allowed_packet = 2M
table_cache = 64
sort_buffer_size = 512K
net_buffer_length = 8K
read_buffer_size = 256K
read_rnd_buffer_size = 512K
myisam_sort_buffer_size = 8M

This configuration file is located at «XAMPP install directory, this is C:\XAMPP by default»\mysql\bin\my.ini.

回答2:

I'm using Xampp 1.7.7 on Windows 7 and had the same problem too. The below is what fixed it:

• Increase mysql.connect_timeout value:
  ; Maximum time (in seconds) for connect timeout. -1 means no limit
  ; http://php.net/mysql.connect-timeout
  mysql.connect_timeout = 10 ; it was 3 by default

• Tried what I did earlier and got an other problem about 'max_allowed_packet'.

• Go to mysql\bin\my.ini and find setting max_allowed_packet = 1M, then change it to 10M: max_allowed_packet = 10M ; It was 1M by default
  

Hope this can help.

Duc

回答3:

This may be because of max_allowed_packet

Change in the my.ini/my.cnf file. Include the single line under [mysqld] in your file

max_allowed_packet=500M

now restart the MySQL service once you are done. You can see it's curent value in mysql like this:

SHOW VARIABLES LIKE 'max_allowed_packet'

You can read about it here http://dev.mysql.com/doc/refman/5.1/en/packet-too-large.html

回答4:

PhpMyAdmin Documentation:

1.16 I cannot upload big dump files (memory, HTTP or timeout problems).

Starting with version 2.7.0, the import engine has been re–written and these problems should not occur. If possible, upgrade your phpMyAdmin to the latest version to take advantage of the new import features.

The first things to check (or ask your host provider to check) are the values of upload_max_filesize, memory_limit and post_max_size in the php.ini configuration file. All of these three settings limit the maximum size of data that can be submitted and handled by PHP. One user also said that post_max_size and memory_limit need to be larger than upload_max_filesize.

There exist several workarounds if your upload is too big or your hosting provider is unwilling to change the settings:

Look at the $cfg['UploadDir'] feature. This allows one to upload a file to the server via scp, ftp, or your favorite file transfer method. PhpMyAdmin is then able to import the files from the temporary directory. More information is available in the Configuration section of this document.

Using a utility (such as BigDump) to split the files before uploading. We cannot support this or any third party applications, but are aware of users having success with it.

If you have shell (command line) access, use MySQL to import the files directly. You can do this by issuing the "source" command from within MySQL: source filename.sql.

回答5:

FOR THOSE DEVELOPERS USING Mac OSX, you will need to change the max_allowed_packet from 1M to 10M within the "my.cnf" file.

max_allowed_packet = 10M

You will probably find the file "my.cnf" in one of these locations:

1. /etc/my.cnf (MOST LIKELY LOCATION FOR MAVERICKS USERS)
2. /etc/mysql/my.cnf
3. SYSCONFDIR/my.cnf
4. $MYSQL_HOME/my.cnf
5. defaults-extra-file (the file specified with --defaults-extra-file=path, if any)
6. ~/.my.cnf

回答6:

Steps for MySQL error 2006 solution:

1. Edit the “my.ini” file found at “:\xampp\mysql\bin\”.
2. In the my.ini file, edit the “max_allowed_packet” by increasing the value.
   • XAMPP default value is 1M. I updated it to 10M.
3. Save the my.ini file.
4. Restart your MySQL and Apache server in XAMPP.

回答7:

I noticed this error while updating Magento from version x to y. Looking at the logs I saw there was an issue in a table.

[ERROR] Index UNQ_DH_CORE_URL_REWRITE_REQUEST_PATH_STORE_ID of databaseabc /core_url_rewrite has 2 columns unique inside InnoDB, but MySQL is asking statistics for 3 columns. Have you mixed up .frm files from different installations? See http://dev.mysql.com/doc/refman/5.1/en/innodb-troubleshooting.html

Fixing this table fixed the issue. In my case I could truncate the table as it was an index that could be generated again.

回答8:

If the increase memory size answers don't work for you, check your code for an infinite loop.

That is what I had in my code which exhausted my memory no matter what I increased it to. The stack trace gives good clues, ensure debugging is turned on, at least locally!