MySQL error 2006: mysql server has gone away

I'm running a server at my office to process some files and report the results to a remote MySQL server.

The files processing takes some time and the process dies halfway through with the following error:

2006, MySQL server has gone away

I've heard about the MySQL setting, wait_timeout, but do I need to change that on the server at my office or the remote MySQL server?

 Answers

It may be easier to check if the connection and re-establish it if needed.

See PHP:mysqli_ping for info on that.

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I had the same problem but changeing max_allowed_packet in the my.ini/my.cnf file under [mysqld] made the trick.

add a line

max_allowed_packet=500M

now restart the MySQL service once you are done.

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In MAMP (non-pro version) I added

--max_allowed_packet=268435456

to ...\MAMP\bin\startMysql.sh

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This error is occur due to expire of wait_timeout .

Just go to mysql server check its wait_timeout :

mysql> SHOW VARIABLES LIKE 'wait_timeout'

mysql> set global wait_timeout = 600 # 10 minute or maximum wait time out you need

http://sggoyal.blogspot.in/2015/01/2006-mysql-server-has-gone-away.html

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On windows those guys using xampp should use this path xampp/mysql/bin/my.ini and change max_allowed_packet(under section[mysqld])to your choice size. e.g

max_allowed_packet=8M

Again on php.ini(xampp/php/php.ini) change upload_max_filesize the choice size. e.g

upload_max_filesize=8M

Gave me a headache for sometime till i discovered this. Hope it helps.

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The unlikely scenario is you have a firewall between the client and the server that forces TCP reset into the connection.

I had that issue, and I found our corporate F5 firewall was configured to terminate inactive sessions that is idle for more than 5 mins.

Once again, this is the unlikely scenario.

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In my case it was low value of open_files_limit variable, which blocked the access of mysqld to data files.

I checked it with :

mysql> SHOW VARIABLES LIKE 'open%';
+------------------+-------+
| Variable_name    | Value |
+------------------+-------+
| open_files_limit | 1185  |
+------------------+-------+
1 row in set (0.00 sec)

After I changed the variable to big value, our server was alive again :

[mysqld]
open_files_limit = 100000

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I found the solution to "#2006 - MySQL server has gone away" this error. Solution is just you have to check two files

1. config.inc.php
2. config.sample.inc.php

Path of these files in windows is

C:\wamp64\apps\phpmyadmin4.6.4

In these two files the value of this:

$cfg['Servers'][$i]['host']must be 'localhost' .

In my case it was:

$cfg['Servers'][$i]['host'] = '127.0.0.1';

change it to:

"$cfg['Servers'][$i]['host']" = 'localhost';

Make sure in both:

1. config.inc.php
2. config.sample.inc.php files it must be 'localhost'.

And last set:

$cfg['Servers'][$i]['AllowNoPassword'] = true;

Then restart Wampserver.

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To change phpmyadmin user name and password

You can directly change the user name and password of phpmyadmin through config.inc.php file

These two lines

$cfg['Servers'][$i]['user'] = 'root';
$cfg['Servers'][$i]['password'] = '';

Here you can give new user name and password. After changes save the file and restart WAMP server.

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If you are using the 64Bit WAMPSERVER, please search for multiple occurrences of max_allowed_packet because WAMP uses the value set under [wampmysqld64] and not the value set under [mysqldump], which for me was the issue, I was updating the wrong one. Set this to something like max_allowed_packet = 64M.

Hopefully this helps other Wampserver-users out there.

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If you know you're going offline for a while, you can close your connection, do your processing, reconnect and write your reports.