General error: 2006 MySQL server has gone away in _drupal_session_write() when max_allowed_packet is not set high enough

That error means you can't connect to mysql, see http://dev.mysql.com/doc/refman/5.0/en/gone-away.html

It means that your MySQL server is configured with a ridiculously small timeout. See the page of the MySQL manual linked in #4 for solutions.

Drupal doesn't connect to MySQL until the first query is sent. A request almost never takes more than a second, and usually less than half a second. If your MySQL server is timing out in that amount of time it means MySQL is misconfigured.

Please verify that you have a reasonable wait_timeout. I suspect simply increasing that will solve the problem.

I got similar errors with a new installation on 64bit Windows 7. This has to do with maximum allowed packet size in MySQL. To solve, add in the [mysqld] section in my.ini: max_allowed_packet=100M and restart MySQL

+1 for the solution above.

#12 above worked for me.

WAMP on Windows 7 localhost. Site ran fine but devel module dpm() call blew up with the 'MySQL server has gone away' message.

#12 solved it, #13 didn't help in my case.

#12 above worked for me too thanks lots

#12 worked for me. Also after reading http://www.midwesternmac.com/blogs/jeff-geerling/mysql-general-errors.

maybe not related but the solution from #20 worked for me. I got sleeping mysql processes running forever (until max connections where reached). It was when visiting admin/config in D7.8

I've done the same thing as wouter99999 instructed in #12 (in a my.cnf file, copied from my-medium.cnf file) does but I extended it to 256M. I'm running MAMP Free and I must say that one site still gives me the error message when I'm trying to add a content type and the other doesn't. No idea why the other doesn't. If anyone knows, please share.

it really is the 256M that does the trick. If I set it to 100M it throws that nasty error.

#12 worked for me aswell. Wamp on wun 7 64.

#12 Worked great for me! Wamp on Win7 Pro 64bit. Many thanks and God bless!

#12 and #13 worked for me. thanks

WAMP on Windows 7 localhost:
#12 removed the issue
Thanks !

hello,

on Acquia dev desktop, win7 I changed in my.cfn

max_allowed_packet=128M to 256M

but I still get this, when I want to add new content type.

PDOException: SQLSTATE[HY000]: General error: 2006 MySQL server has gone away
and
Uncaught exception thrown in session handler.

PDOException: There is already an active transaction in _drupal_session_write() (line 206 of...

how can I solve it?

thank you.
S.

Post #12 http://drupal.org/node/1014172#comment-4142046
says change my.ini

Look in mysql/bin. This worked for me so far...

I had a similar problem, turned out the comment (#12) by wouter99999 fixed it. Thanks wouter99999, you saved me from a world of pain!!

wouter99999, thank you! your solution from #12 helped me well.

When you're on Linux, don't look for my.ini but for my.cnf

sudo gvim /opt/lampp/etc/my.cnf
sudo /opt/lampp/lampp restart

ntx wouter99999 http://drupal.org/node/1014172#comment-4142046

#12 fixed my issue. Thank you.

#12 fixed my issue, but it had to be in the [mysqld] section (edited via WAMP "my.ini" option)
Cheers for the post.

Just highlighting this (#34) , make sure it's in the [mysqld] section, by default there is the same setting in the [mysqldump] section, can be confusing for some.

I have tried all the solutions given above but I'm still getting the same error message(MESSAGE BELOW). I am running Zend Server CE with the my-huge.ini as the default my.ini. I need help because all my drupal projects are inaccessible.

Error
The website encountered an unexpected error. Please try again later.
Error messagePDOException: SQLSTATE[42000]: Syntax error or access violation: 1286 Unknown table engine 'InnoDB': SELECT expire, value FROM {semaphore} WHERE name = :name; Array ( [:name] => variable_init ) in lock_may_be_available() (line 167 of C:\Zend\Apache2\htdocs\academy.org\includes\lock.inc).

Uncaught exception thrown in shutdown function.
PDOException: SQLSTATE[42000]: Syntax error or access violation: 1286 Unknown table engine 'InnoDB': DELETE FROM {semaphore} WHERE (value = :db_condition_placeholder_0) ; Array ( [:db_condition_placeholder_0] => 68667015250329455dbcd27.47278376 ) in lock_release_all() (line 269 of C:\Zend\Apache2\htdocs\academy.org\includes\lock.inc).

max_allowed_packet = 16M solved my problem

max_allowed_packet=100M fixed mine ... tanks ...

#12 helped mee too. Thank you!

NOTE: I found this to be a very time consuming and frustrating problem to solve. I leave this post as search bait to help others with a similar issue.

On my Drupal 7 site I was experiencing WSOD when attempting to add/edit a menu item (/structure/menu/item//edit), content type (admin/structure/types/manage/) or feature (admin/structure/features/create). All the tips provided at http://drupal.org/node/158043 on dealing with WSOD were of no help. I increased my PHP memory and added error reporting statements to index.php (see http://drupal.org/node/158043), but still there was the White Screen of Death and a total lack of insightful messages in any of the error log files (watchdog, php, apache, sql).

Further experimenting, I tried simplifying my environment. After I turned off DEVEL and I was presented with a Fatal error: Exception thrown without a stack frame in Unknown on line 0 error when visiting the page. Not a fix, but much better than a blank screen.

I then found a tip at http://www.drupal4hu.com/node/222 which suggested the issue might be one of the following:

1. There was an exception while handling an exception.
2. There was an exception while running a destructor.
3. There was an exception while closing the session.
4. There was an exception while running a shutdown function.

I followed the writer's recommendation of wrapping my index.php within a try-catch block and saving the catch to an error log. My index.php file now looks like:

try{
error_reporting(E_ALL);
ini_set('display_errors', TRUE);
ini_set('display_startup_errors', TRUE);

/**
 * @file
 * The PHP page that serves all page requests on a Drupal installation.
 * ...
 */

/**
 * Root directory of Drupal installation.
 */
define('DRUPAL_ROOT', getcwd());

require_once DRUPAL_ROOT . '/includes/bootstrap.inc';
drupal_bootstrap(DRUPAL_BOOTSTRAP_FULL);
menu_execute_active_handler();

} catch (exception $e) {file_put_contents('/tmp/drupal_error.log', $e->getMessage() . ' file: ' . $e->getFile() . ' on line '. $e->getLine()); }

NOTE: Less the ending ?>.

I visited the page again and noticed that the following error was written to my drupal_error.log file.
SQLSTATE[HY000]: General error: 2006 MySQL server has gone away

Which then led me to this page and to posts 12 & 13. If you follow post 13's link you will find the following:

This is very critical error found in MySQL. This error originate when you are dealt with huge records. There are various unanswered forum you will found when you Google that problem. The reason behind this crash is packet size. By default, MySQL configuration max_allowed_packet is set it to 16M. This settings may introduce this exception in your website..

Solution:
To resolve that problem you needs to increase max_allowed_packet variable in MySQL. Add following line in my.ini (or my.cnf)
max_allowed_packet=100M

Save the file and restart MySQL service. Now onward you will never get that kind exception in your open source / website.

I'm using MAMP on MacOS. So I modified the MySQL's my.cnf file and upped the max_allowed_packet default from 1M to 100M. Saved and rebooted MAMP. Problem solved. Yeah!

Updated to 7.16 and got the error. # 12 worked but instead of 100M i set it at max_allowed_packet = 10M.

Thanks.

After moving my site to a vps I started seeing this error. The error was volatile and I could not reproduce manually - it was very sporadic.

I attempted to fix it by increasing the max_packet_size, however this didn't work.

I noticed some references to the theme registry in the error. My site utilizes Zen.

I went into the appearance admin section and turned off "Rebuild theme registry on every page. " in the theme settings.

This fixed the solution for me.

As with ydahi (#43), it was the Zen theme which caused the aforementioned error with SQL, this after I had updated to Zen 7.x-5.1. No more playing with Zen, I guess!

Posted by wouter99999 on February 26, 2011 at 6:44pm
I got similar errors with a new installation on 64bit Windows 7. This has to do with maximum allowed packet size in MySQL. To solve, add in the [mysqld] section in my.ini: max_allowed_packet=100M and restart MySQL

Perfect! Fixed my error on WAMP. I thought it had to do with my install of Commerce as it happened right behind installing a Commerce Module.

#12 is not working for me,
i am using wamp my sql 5.5

i have two web site working locally. one is working fine but the other is not working when i click add content type or edit a content type. but other wise the site is working perfectly.

it seemed that drupal needed more packages when reading from databases since limit was set to 1M for some reason it was the default since there was not config file.

the site was still working, since for normal use it doesn't take that much from the database, but when logged into the administration panel it did take a lot data from mysql, over 1M as it was set..... It was working with all the modules that I already installed but not all configured and up and running, since some of them were in the off mode... I just Enabled some features of some modules on the modules panel and started giving me that error, nothing displayed other than showing that error where said: "SERVER HAS GONE AWAY"...

my first reaction was::: FUCK!! as usual.. then i started thinking.. and my first though was to remove some modules from the modules folder, but then I figured that some modules are needed by other modules.. so that would take forever, ... then I realized that it was showing a server issue... so i thought it was apache.. then mysql, and i started looking for mysql config file and no file found.,.. then I started reading about it mysql website and it popped up

so i knew it was mysql-server configuration, then I saw a post in drupal that said it was the packages drupal was getting from mysql... so what need to be modify was:

max_allowed_packet=1M to 2 or more Megs in mysql's my.cnf file.

Ran into the same problem. This post on StackOverflow fixed it for me.

Skip-locking was removed in MySQL 5.5. See here. Edit your my.cnf file and change "skip-locking" to "skip-external-locking".

My setup:
- MAMP 1.9.6.1 (PHP 5.3.5, mySQL 5.5.9)
- MAMP/conf/my.cnf
- Drupal 7.21

I'm using gnu/linux fedora and add the setting of max_allowed_packet like comment #12 in the file /etc/my.cnf did not work.
After some testing i could change the configuration max_allowed_packet using the /etc/my.cnf.d/server.cnf and now the error gone away from my pc

#12 is working for me.

Thanks.

#12 worked for MAMP 2.1.1. on OSX 10.8

hi
sorry for my english
i test it and solve my problem.
in mysql shell insert this command
mysql >> SET GLOBAL max_allowed_packet=32*1024*1024;
and then import database

my os is centos 5

thanks #12. Works just fine

#12 worked perfectly for me! Many thanks.

#12 worked for me, too! Thanks alot!

Thanks, that's the general solution

For what It's worth, last step in installing Drupal Commons, this worked for me. Thanks..

Default Re: High load: mysql --log-error=/var/lib/mysql/...

Since you are using MySQL 5.0, please try the following values to replace your existing /etc/my.cnf file (which might not be accurate to use as MySQL had been restarted in less than 24 hours when mysqltuner.pl was run):

Code:

[mysqld]
innodb_buffer_pool_size=20M
key_buffer_size = 512M
max_allowed_packet=100M
max_connections=500
max_heap_table_size=24M
open_files_limit=5000
query_cache_size=8M
table_cache = 2200
thread_cache_size=4
tmp_table_size=40M
log-slow-queries=/var/lib/mysql/slow.log

After this, then create the slow query log using these commands:

Code:

cd /var/lib/mysql
touch slow.log
chmod 660 slow.log
chown mysql:mysql slow.log

After doing that, then restart MySQL:

Code:

/etc/init.d/mysql restart
this help me solve my problem thanks

I was having a problem with this uncaught exception error and server has gone away message when I tried to edit an order in drupal commerce (on shared hosting). I went back to my local host and checked if it gave the same error. It gave a different error relating to drupal firebug module. I then turned off Drupal Firebug and Drupal for Firebug Preprocessor modules. The error went away. Hope this helps somebody.

#12 Seems to solve this issue, but my website is hosted and I don't have access to that specific file. It is really bugging me as I can't use my admin user at all, I'm stuck. Everything was working well and have been for the last 3 months, on a production server, than I had many spams and tried to put in antispam module, and boom, now my admin user gets the WSOD , but not restricted users.

The site is still available for most, but my admin is dead, I really need to fix this, but I don't know how to change that setting in a shared server environment.

Thank for any help you can provide!

I'm having a similar problem while trying to install Drupal 7.

After installing 27 modules (of 28) I get the following message:

'An AJAX HTTP error occurred. HTTP Result Code: 500 Debugging information follows. Path: http://localhost/drupal/install.php?profile=standard&locale=en&id=1&op=do StatusText: Service unavailable (with message) ResponseText: PDOException: SQLSTATE[HY000]: General error: 2006 MySQL server has gone away: SELECT expire, value FROM {semaphore} WHERE name = :name; Array ( [:name] => menu_rebuild ) in lock_may_be_available() (line 167 of C:\wamp\www\drupal\includes\lock.inc).Uncaught exception thrown in shutdown function.PDOException: SQLSTATE[HY000]: General error: 2006 MySQL server has gone away: DELETE FROM {semaphore} WHERE (value = :db_condition_placeholder_0) ; Array ( [:db_condition_placeholder_0] => 802228002541876118e8773.14607894 ) in lock_release_all() (line 269 of C:\wamp\www\drupal\includes\lock.inc).Uncaught exception thrown in session handler.PDOException: SQLSTATE[HY000]: General error: 2006 MySQL server has gone away: SELECT 1 AS expression FROM {sessions} sessions WHERE ( (sid = :db_condition_placeholder_0) AND (ssid = :db_condition_placeholder_1) ); Array ( [:db_condition_placeholder_0] => ZLNqcOjZv5_OY8Y_fNwE0Il6hHmlJCLVL9qK5XUBTIo [:db_condition_placeholder_1] => ) in _drupal_session_write() (line 209 of C:\wamp\www\drupal\includes\session.inc).'

I have raised the number of the max_allowed_packet to various high amounts.
I have installed WAMP anew.
I have raised other numbers in my my.ini.
Each time I delete Drupal, my databank and my history in Chrome.

I have tried a lot of things, but I do not manage to install Drupal correctly. What can I try next?

Thanks,
Mariska.

#12 worked for me, too!! Thanks alot!!

#12 worked for me.. Thanks

#12 works well :-)

#12 Worked for me. Thanks

#12 did not work for me - and I'm still flailing about trying to install Drupal (been at this since March 17). If anyone can help I will really appreciate it. It seems Mariska #61 is having similar issues...

Here's what I've tried.

• Installed wampserver 64-bit on my Windows 7 64-bit machine following the instructions on the drupalize.me video

• Installed Drupal 7.35 per the instructions on the drupalize.me video but at Step 26 I get a “General error: 2006 MySQL server has gone away” error. WAMP goes from green to orange immediately at this step.

• Uninstalled wampserver 64-bit, reinstalled and (per #12) changed the MySQL “my.ini” file line “max_allowed_packet” from 1M to 100M. Reinstalled Drupal, but at Step 26 I get the same error.

• Uninstalled wampserver 64-bit, reinstalled and (per #12) changed the MySQL “my.ini” file line “max_allowed_packet” from 1M to 100M. Also (per another page at Drupal.org) changed [wampmysql] to [wampmysql64]. Reinstalled Drupal 7.35, but at Step 26 I get the same error.

• Uninstalled wampserver 64-bit, installed wampserver 32-bit and (per #12) changed the MySQL “my.ini” file line “max_allowed_packet” from 1M to 100M. Reinstalled Drupal 7.35, but at Step 26 I get the same error.

It’s obviously something wrong with MySQL – but what? I’ve search all over the internet, and the MaxPackets solution in #12 seems to fix it for most people but not for me?

Please can anyone help?

I was trying to install 7.36 locally and kept getting the a similar issue as Mariska #61 and schellenbergk #66. I configured my mysql settings to consume more resources and have a longer timeout and it did nothing! I couldn't figure out why it was still throwing the ajax error Mariska was getting. When I checked the mysql log file it kept saying that I didn't have permissions. I'm on win7 so...yes...I do have permission. Why had I been able to do this on my old computer all the time, and not this one? The only difference I could find was that McAfee came installed on this one (I had been using avast). When I disabled it I was able to install drupal on my localhost like normal! Very frustrating, so if that's the situation you find yourself in, give it a try. It might save you some time, if you can remember to turn your antivirus back on one you're installed :)

So after simply waiting a few weeks, I tried again and the issue has gone away. It seems the latest version has fixed whatever incompatibilities existed in the Windows configuration that I and a handful of other had.

Many thanks!!

I had this error and came up with my own fix.

I am using wampp on windows 7. The problem appeared on local host.
I tried changing the max allowed packet. No effect. I tried restarting mysql server from xampp. No effect.

Another symptom I had was that when I had the problem, on starting mysql server at first there was a message which seemed to say there was a port conflict, then mysql server said that it started successfully.

I checked for port conflicts between mysql server and some other running process but didn't find one.

Here is what worked for me.

I used netstat to get the PID of the running mysql process (or at least whatever process was using the same port as mysql).
I then went to task manager found that process and killed it.
In xampp I restarted mysql server.

Problem fixed. I don't really know why it worked. Best guess is that mysql had somehow started twice, or at least when it stopped it still kept some resources and/or did not stop and clear down completely.
Hope this might help someone.

Hello , I load my drupal website via Fillezilla and it has received . When finished, in my browser I grabbed www.monsite.com/install.php to finalize the publication and once the party of choice for database I are mistakes once I selects the base all data by inserting the name of the database and password . What should I do please ?

I had to increase to:

max_allowed_packet = 200M

Since my code was dumping very big Guzzle objects via watchdog.

it has something todo with enabling multiple new modules in one go
and then there can be a fail

if on a shared server that works perfect for all other drupal sites with the same workload and max allowed settings and you are on a shared server
what can you do ,

I've tried everything and I didn't get work, but then I took a look into the mysql_error.log:

[ERROR] InnoDB: The total blob data length (1066257) is greater than 10% of the total redo log size (10485760). Please increase total redo log size.

So I increased innodb_log_file_size from 5M to 256M in my.ini.

My changes in my.ini are

innodb_log_file_size = 256M

And under [mysqld] in my.ini:

max_allowed_packet = 100M

Now everything is working fine.

max_allowed_packet is documented in the installation requirements.

#12 fixed my issue too

#12 worked for me too. Many thanks.

I am setting the correct status because of #74.

#12 is not working for me.. I was changed the max execution limit but still occuring the same error. Below i have place the error details.

PDOException: SQLSTATE[HY000] [2006] MySQL server has gone away in lock_may_be_available() (line 167 of C:\xamppnew\htdocs\csb\src\includes\lock.inc).

Can anyone please suggest this?????

Thanks,

Idris

@idris_9791 Please follow: Solving “MySQL server has gone away”, mysql error 2006

#12 worked for me too. Many thanks.

Thank you #12

I have updated max_allowed_packet = 200M but still not working for me.

I am using Drupal 8 on Ubuntu 14.04.

Getting below error message randomly.

The website encountered an unexpected error. Please try again later.
PDOException: SQLSTATE[HY000] [2002] Connection refused in Drupal\Component\DependencyInjection\PhpArrayContainer->createService() (line 79 of /var/www/html/MYPROJECT/code/core/lib/Drupal/Component/DependencyInjection/PhpArrayContainer.php).

Sometimes it shows below error message as well.

The website encountered an unexpected error. Please try again later.
Drupal\Core\Database\DatabaseExceptionWrapper: SQLSTATE[HY000]: General error: 2006 MySQL server has gone away: CREATE TABLE {cache_config} ( `cid` VARCHAR(255) BINARY CHARACTER SET ascii COLLATE ascii_general_ci NOT NULL DEFAULT '' COMMENT 'Primary Key: Unique cache ID.', `data` LONGBLOB NULL DEFAULT NULL COMMENT 'A collection of data to cache.', `expire` INT NOT NULL DEFAULT 0 COMMENT 'A Unix timestamp indicating when the cache entry should expire, or -1 for never.', `created` DECIMAL(14, 3) NOT NULL DEFAULT 0 COMMENT 'A timestamp with millisecond precision indicating when the cache entry was created.', `serialized` SMALLINT NOT NULL DEFAULT 0 COMMENT 'A flag to indicate whether content is serialized (1) or not (0).', `tags` LONGTEXT NULL DEFAULT NULL COMMENT 'Space-separated list of cache tags for this entry.', `checksum` VARCHAR(255) CHARACTER SET ascii COLLATE ascii_general_ci NOT NULL COMMENT 'The tag invalidation checksum when this entry was saved.', PRIMARY KEY (`cid`), INDEX `expire` (`expire`) ) ENGINE = InnoDB DEFAULT CHARACTER SET utf8mb4 COMMENT 'Storage for the cache API.'; Array ( ) in Drupal\Core\Config\CachedStorage->readMultiple() (line 105 of core/lib/Drupal/Core/Config/CachedStorage.php). 

Anybody has faced this issue with Drupal 8? Please help.

Thanks

#12 worked for me

Increasing the max_allowed_packed to 16 M worked for me.

#12 worked for me

Well, that was several wasted days for a simple fix (#12 worked - had switched to XAMPP). Moral is, read ALL of the logs. THANK YOU!!

It is also published in https://www.drupal.org/docs/7/system-requirements/database-server

Any solution for shared server?

#12 Worked for me.
Thank you very much.

Required Mysql configuration to avoid such error
https://www.drupal.org/node/259580

max_allowed_packet = 100M only Worked for me on drupal 8.3.6

I spent a long time finding a solution for this, so here's my two cents.

I had the same problem when updating an old drupal 6 website to drupal 7.
In my case I could not set max_allowed_packet to more than 32M, and with 32M I still had the error.
But actually I took a look at the session database and noticed that the table was more than 200M in a 300M database.
It seems like if all users sessions ever were still stored on the database without cleaning.
Actually, you can empty this table safely (it only has the side effect of disconnecting all active users, which in my case, as I am migrating the website to a new version, I do not care about...)

After fixing this, I could load the update.php, but ran into a similar problem this time mentioning the searchindex table, which again I cleared...

I have run into this issue as well, but raising the max_allowed_packet value to even 1024 does not help.

I don't know what caused the error to get triggered all of a sudden. I restarted the server recently after some standard apt upgrades. There are several other sites running with a similar setup, and the problem does not happen there.

I tried several things...

• raising the max_allowed_packet in /etc/mysql/my.cnf to 1024M
• raising the wait_timeout in /etc/mysql/my.cnf to 600
• raising the open_files_limit using this method
• truncating the sessions table
• truncating the watchdog table

Hope someone has an idea how to troubleshoot from here!

Additional uncaught exception thrown while handling exception.
Original

PDOException: SQLSTATE[HY000]: General error: 2006 MySQL server has gone away: SELECT * FROM {menu_router} WHERE path IN (:ancestors_0) ORDER BY fit DESC LIMIT 0, 1; Array ( [:ancestors_0] =&gt; node ) in menu_get_item() (line 475 of /home/<user>/public_html/includes/menu.inc).
Additional

PDOException: SQLSTATE[HY000]: General error: 2006 MySQL server has gone away: SELECT s.lid, t.translation, s.version FROM {locales_source} s LEFT JOIN {locales_target} t ON s.lid = t.lid AND t.language = :language WHERE s.source = :source AND s.context = :context AND s.textgroup = &#039;default&#039;; Array ( [:language] =&gt; da [:source] =&gt; The website encountered an unexpected error. Please try again later. [:context] =&gt; ) in locale() (line 719 of /home/<user>/public_html/modules/locale/locale.module).
Uncaught exception thrown in session handler.

PDOException: SQLSTATE[HY000]: General error: 2006 MySQL server has gone away: SELECT 1 AS expression FROM {sessions} sessions WHERE ( (sid = :db_condition_placeholder_0) AND (ssid = :db_condition_placeholder_1) ); Array ( [:db_condition_placeholder_0] =&gt;<somelongstring> [:db_condition_placeholder_1] =&gt;<somelongstring> ) in _drupal_session_write() (line 209 of /home/<user>/public_html/includes/session.inc). 

Specs

Ubuntu 16.04, PHP 7.1.26-1
mysql Ver 14.14 Distrib 5.7.25, for Linux (x86_64)

I have used the Drupal-VM for setting up the server, with a NGINX and Node.js service running on a VPS with 8G RAM.

$ free -m
              total        used        free      shared  buff/cache   available
Mem:           7793        1190        5541         100        1061        6228
Swap:          2047           0        2047

Configuration

my.cnf

[client]
port = 3306
socket = /var/run/mysqld/mysqld.sock

[mysqld]
port = 3306
bind-address = 0.0.0.0
datadir = /var/lib/mysql
socket = /var/run/mysqld/mysqld.sock
pid-file = /var/run/mysqld/mysqld.pid

# Logging configuration.
log-error = /var/log/mysql/mysql.err

# Slow query log configuration.
slow_query_log = 1
slow_query_log_file = /var/log/mysql/mysql-slow.log
long_query_time = 2


# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links = 0

# User is ignored when systemd is used (fedora >= 15).
user = mysql

# http://dev.mysql.com/doc/refman/5.5/en/performance-schema.html
;performance_schema

# Memory settings.
key_buffer_size = 256M
max_allowed_packet = 1024M
table_open_cache = 256
sort_buffer_size = 1M
read_buffer_size = 1M
read_rnd_buffer_size = 4M
myisam_sort_buffer_size = 64M
thread_cache_size = 8
query_cache_type = 0
query_cache_size = 16M
query_cache_limit = 1M
max_connections = 151
tmp_table_size = 16M
max_heap_table_size = 16M
group_concat_max_len = 1024
join_buffer_size = 262144

wait_timeout = 600
lower_case_table_names = 0
event_scheduler = OFF

# This will not be respected here so we set this in /etc/systemd/system/mysql.service
# open_files_limit = 10000

# InnoDB settings.
innodb_large_prefix = 1
innodb_file_format = barracuda
innodb_file_per_table = 1
innodb_buffer_pool_size = 256M
innodb_log_file_size = 64M
innodb_log_buffer_size = 8M
innodb_flush_log_at_trx_commit = 1
innodb_lock_wait_timeout = 50

[mysqldump]
quick
max_allowed_packet = 64M

[mysqld_safe]
pid-file = /var/run/mysqld/mysqld.pid

Variables:

mysql> SHOW VARIABLES LIKE 'max_allowed_packet';
+--------------------+------------+
| Variable_name      | Value      |
+--------------------+------------+
| max_allowed_packet | 1073741824 |
+--------------------+------------+
1 row in set (0.01 sec)

mysql> SHOW VARIABLES LIKE 'open_files_limit';
+------------------+-------+
| Variable_name    | Value |
+------------------+-------+
| open_files_limit | 10000 |
+------------------+-------+
1 row in set (0.00 sec)



mysql> SHOW VARIABLES LIKE 'wait_timeout';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| wait_timeout  | 28800 |
+---------------+-------+
1 row in set (0.01 sec)

mysql> SELECT table_schema "mydb",
    ->         ROUND(SUM(data_length + index_length) / 1024 / 1024, 1) "DB Size in MB" 
    -> FROM information_schema.tables 
    -> GROUP BY table_schema; 
+--------------------+---------------+
| mydb                 | DB Size in MB |
+--------------------+---------------+
| mydb                 |          11.2 |
| information_schema |           0.2 |
+--------------------+---------------+
2 rows in set (0.04 sec)

Update:

I never managed to fix this error by manipulating MySQL or OS settings. After consulting with others our diagnosis pointed to corrupted tables in the database.

We could not even run simple mysql count statements against certain tables without crashing the mysql process and in the mysql.err log we had ugly errors like these:

InnoDB: Assertion failure in thread 140192398046976 in file btr0cur.cc line 7218
InnoDB: Failing assertion: space_id == page_get_space_id(page)

Luckily the tables didn't contain vital data, so I ended up truncating the tables.

I experienced this error across different servers around the same time which makes me suspect that a hardware / storage issue might be in play.

#12 works - Drupal 8 php 7.2.14
Thanks

+1 #12
it worked for me

#12 above worked for me in Mac

I faced this problem in Drupal 7.72 when i try to open the new content type admin page. I changed the value of the variable "Maximum packet size" in the mySQL Server settings from 1MB to 2MB and it worked! Server System: CentOS Linux.

Set Variable "max_allowed_packet=512M" to resolved my issue:
mysql Ver 14.14 Distrib 5.7.28, for macos10.14 (x86_64) using EditLine wrapper
macOS Catalina
Version: 10.15.3

https://www.drupal.org/project/drupal/issues/984112#comment-13795388

#12 worked for me, thank you so much dear.

#12 did the trick, thanks.

I am also getting the same error. #12 resolved my error.

If you use lando:
.lando.yml

database:
    type: mysql:5.7
    portforward: true
    configuration:
      properties:
        max_allowed_packet: 77