I tried to import a large sql file through phpMyAdmin...But it kept showing error
'MySql server has gone away'
What to do?
As stated here:
Two most common reasons (and fixes) for the MySQL server has gone away
(error 2006) are:
Server timed out and closed the connection. How to fix:
check that wait_timeout variable in your mysqld’s my.cnf configuration file is large enough. On Debian: sudo nano
/etc/mysql/my.cnf, set wait_timeout = 600 seconds (you can
tweak/decrease this value when error 2006 is gone), then sudo
/etc/init.d/mysql restart. I didn't check, but the default value for
wait_timeout might be around 28800 seconds (8 hours).
Server dropped an incorrect or too large packet. If mysqld gets a packet that is too large or incorrect, it assumes that something has
gone wrong with the client and closes the connection. You can increase
the maximal packet size limit by increasing the value of
max_allowed_packet in my.cnf file. On Debian: sudo nano
/etc/mysql/my.cnf, set max_allowed_packet = 64M (you can
tweak/decrease this value when error 2006 is gone), then sudo
/etc/init.d/mysql restart.
Edit:
Notice that MySQL option files do not have their commands already available as comments (like in php.ini for instance). So you must type any change/tweak in my.cnf or my.ini and place them in mysql/data directory or in any of the other paths, under the proper group of options such as [client], [myslqd], etc. For example:
[mysqld]
wait_timeout = 600
max_allowed_packet = 64M
Then restart the server. To get their values, type in the mysql client:
> select ##wait_timeout;
> select ##max_allowed_packet;
For me this solution didn't work out so I executed
SET GLOBAL max_allowed_packet=1073741824;
in my SQL client.
If not able to change this with MYSql service running, you should stop the service and change the variable in "my.ini" file.
For example:
max_allowed_packet=20M
If you are working on XAMPP then you can fix the MySQL Server has gone away issue with following changes..
open your my.ini file
my.ini location is (D:\xampp\mysql\bin\my.ini)
change the following variable values
max_allowed_packet = 64M
innodb_lock_wait_timeout = 500
If you are running with default values then you have a lot of room to optimize your mysql configuration.
The first step I recommend is to increase the max_allowed_packet to 128M.
Then download the MySQL Tuning Primer script and run it. It will provide recommendations to several facets of your config for better performance.
Also look into adjusting your timeout values both in MySQL and PHP.
How big (file size) is the file you are importing and are you able to import the file using the mysql command line client instead of PHPMyAdmin?
If you are using MAMP on OS X, you will need to change the max_allowed_packet value in the template for MySQL.
You can find it at: File > Edit template > MySQL my.cnf
Then just search for max_allowed_packet, change the value and
save.
I had this error and other related ones, when I imported at 16 GB SQL file. For me, editing my.ini and setting the following (based on several different posts) in the [mysqld] section:
max_allowed_packet = 110M
innodb_buffer_pool_size=511M
innodb_log_file_size=500M
innodb_log_buffer_size = 800M
net_read_timeout = 600
net_write_timeout = 600
If you are running under Windows, go to the control panel, services, and look at the details for MySQL and you will see where my.ini is. Then after you edit and save my.ini, restart the mysql service (or restart the computer).
If you are using HeidiSQL, you can also set some or all of these using that.
I solved my issue with this short /etc/mysql/my.cnf file :
[mysqld]
wait_timeout = 600
max_allowed_packet = 100M
The other reason this can happen is running out of memory. Check /var/log/messages and make sure that your my.cnf is not set up to cause mysqld to allocate more memory than your machine has.
Your mysqld process can actually be killed by the kernel and then re-started by the "safe_mysqld" process without you realizing it.
Use top and watch the memory allocation while it's running to see what your headroom is.
make a backup of my.cnf before changing it.
I got same issue with
$image_base64 = base64_encode(file_get_contents($_FILES['file']['tmp_name']) );
$image = 'data:image/jpeg;base64,'.$image_base64;
$query = "insert into images(image) values('".$image."')";
mysqli_query($con,$query);
In \xampp\mysql\bin\my.ini file of phpmyadmin we get only
[mysqldump]
max_allowed_packet=110M
which is just for mysqldump -u root -p dbname . I resolved my issue by replacing above code with
max_allowed_packet=110M
[mysqldump]
max_allowed_packet=110M
I updated "max_allowed_packet" to 1024M, but it still wasn't working. It turns out my deployment script was running:
mysql --max_allowed_packet=512M --database=mydb -u root < .\db\db.sql
Be sure to explicitly specify a bigger number from the command line if you are donig it this way.
If your data includes BLOB data:
Note that an import of data from the command line seems to choke on BLOB data, resulting in the 'MySQL server has gone away' error.
To avoid this, re-create the mysqldump but with the --hex-blob flag:
http://dev.mysql.com/doc/refman/5.7/en/mysqldump.html#option_mysqldump_hex-blob
which will write out the data file with hex values rather than binary amongst other text.
PhpMyAdmin also has the option "Dump binary columns in hexadecimal notation (for example, "abc" becomes 0x616263)" which works nicely.
Note that there is a long-standing bug (as of December 2015) which means that GEOM columns are not converted:
Back up a table with a GEOMETRY column using mysqldump?
so using a program like PhpMyAdmin seems to be the only workaround (the option noted above does correctly convert GEOM columns).
If it takes a long time to fail, then enlarge the wait_timeout variable.
If it fails right away, enlarge the max_allowed_packet variable; it it still doesn't work, make sure the command is valid SQL. Mine had unescaped quotes which screwed everything up.
Also, if feasible, consider limiting the number of inserts of a single SQL command to, say, 1000. You can create a script that creates multiple statements out of a single one by reintroducing the INSERT... part every n inserts.
i got a similar error.. to solve this just open my.ini file..here at line no 36 change the value of maximum allowed packet size ie. max_allowed_packet = 20M
Make sure mysqld process does not restart because of service managers like systemd.
I had this problem in vagrant with centos 7. Configuration tweaks didn't help. Turned out it was systemd which killed mysqld service every time when it took too much memory.
I had similar error today when duplicating database (MySQL server has gone away...), but when I tried to restart mysql.server restart I got error
ERROR! The server quit without updating PID ...
This is how I solved it:
I opened up Applications/Utilities/ and ran Activity Monitor
quit mysqld
then was able to solve the error problem with
mysql.server restart
I am doing some large calculations which involves the mysql connection to stay long time and with heavy data. i was facing this "Mysql go away issue". So i tried t optimize the queries but that doen't helped me then i increased the mysql variables limit which is set to a lower value by default.
wait_timeout
max_allowed_packet
To the limit what ever suits to you it should be the Any Number * 1024(Bytes). you can login to terminal using 'mysql -u username - p' command and can check and change for these variable limits.
For GoDaddy shared hosting
On GoDaddy shared hosting accounts, it is tricky to tweak the PHP.ini etc files. However, there is another way and it just worked perfectly for me. (I just successfully uploaded a 3.8Mb .sql text file, containing 3100 rows and 145 cols. Using the IMPORT command in phpMyAdmin, I was getting the dreaded MySQL server has gone away error, and no further information.)
I found that Matt Butcher had the right answer. Like Matt, I had tried all kinds of tricks, from exporting MySQL databases in bite-sized chunks, to writing scripts that break large imports into smaller ones. But here is what worked:
(1) CPANEL ---> FILES (group) ---> BACKUP
(2a) Under "Partial Backups" heading...
(2b) Under "Download a MySQL Database Backup"
(2c) Choose your database and download a backup (this step optional, but wise)
(3a) Directly to the right of 2b, under heading "Restore a MySQL Database Backup"
(3b) Choose the .SQL import file from your local drive
(3c) True happiness will be yours (shortly....) Mine took about 5 seconds
I was able to use this method to import a single table. Nothing else in my database was affected -- but that is what step (2) above is intended to protect against.
Notes:
a. If you are unsure how to create a .SQL import file, use phpMyAdmin to export a table and modify that file structure.
SOURCE:
Matt Butcher 2010 Article
If increasing max_allowed_packet doesn't help.
I was getting the same error as you when importing a .sql file into my database via Sequel Pro.
The error still persisted after upping the max_allowed_packet to 512M so I ran the import in the command line instead with:
mysql --verbose -u root -p DatabaseName < MySQL.sql
It gave the following error:
ASCII '\0' appeared in the statement, but this is not allowed unless option --binary-mode is enabled
I found a couple helpful StackOverflow questions:
Enable binary mode while restoring a Database from an SQL dump
Mysql ERROR: ASCII '\0' while importing sql file on linux server
In my case, my .sql file was a little corrupt or something. The MySQL dump we get comes in two zip files that need to be concatenated together and then unzipped. I think the unzipping was interrupted initially, leaving the file with some odd characters and encodings. Getting a fresh MySQL dump and unzipping it properly worked for me.
Just wanted to add this here in case others find that increasing the max_allowed_packet variable was not helping.
None of the solutions regarding packet size or timeouts made any difference for me. I needed to disable ssl
mysql -u -p -hmyhost.com --disable-ssl db < file.sql
https://dev.mysql.com/doc/refman/5.7/en/encrypted-connections.html
Related
I'm trying to import a Wordpress Plugin database that stores files in the table using the longblob datatype. The database is on one server, so I exported it to import on another server, but have received various errors, the latest of which is "Got a packet bigger than 'max_allowed_packet' bytes".
Previously, these commands were run on the server: set global max_allowed_packet=10000000; and set global net_buffer_length=1000000; The server has been restarted since then.
Any ideas as to what would cause this? I'm fairly new to all of this, so I may not be providing all of the necessary information. Let me know if I need to clarify.
Thanks in advance for your time!
Set the variable in your my.cnf file. On linux you can find this at /etc/my.cnf and add the following line:
max_allowed_packet = 64M
Don't forget to restart mysql after you've made this change.
I tried to import a large sql file through phpMyAdmin...But it kept showing error
'MySql server has gone away'
What to do?
As stated here:
Two most common reasons (and fixes) for the MySQL server has gone away
(error 2006) are:
Server timed out and closed the connection. How to fix:
check that wait_timeout variable in your mysqld’s my.cnf configuration file is large enough. On Debian: sudo nano
/etc/mysql/my.cnf, set wait_timeout = 600 seconds (you can
tweak/decrease this value when error 2006 is gone), then sudo
/etc/init.d/mysql restart. I didn't check, but the default value for
wait_timeout might be around 28800 seconds (8 hours).
Server dropped an incorrect or too large packet. If mysqld gets a packet that is too large or incorrect, it assumes that something has
gone wrong with the client and closes the connection. You can increase
the maximal packet size limit by increasing the value of
max_allowed_packet in my.cnf file. On Debian: sudo nano
/etc/mysql/my.cnf, set max_allowed_packet = 64M (you can
tweak/decrease this value when error 2006 is gone), then sudo
/etc/init.d/mysql restart.
Edit:
Notice that MySQL option files do not have their commands already available as comments (like in php.ini for instance). So you must type any change/tweak in my.cnf or my.ini and place them in mysql/data directory or in any of the other paths, under the proper group of options such as [client], [myslqd], etc. For example:
[mysqld]
wait_timeout = 600
max_allowed_packet = 64M
Then restart the server. To get their values, type in the mysql client:
> select ##wait_timeout;
> select ##max_allowed_packet;
For me this solution didn't work out so I executed
SET GLOBAL max_allowed_packet=1073741824;
in my SQL client.
If not able to change this with MYSql service running, you should stop the service and change the variable in "my.ini" file.
For example:
max_allowed_packet=20M
If you are working on XAMPP then you can fix the MySQL Server has gone away issue with following changes..
open your my.ini file
my.ini location is (D:\xampp\mysql\bin\my.ini)
change the following variable values
max_allowed_packet = 64M
innodb_lock_wait_timeout = 500
If you are running with default values then you have a lot of room to optimize your mysql configuration.
The first step I recommend is to increase the max_allowed_packet to 128M.
Then download the MySQL Tuning Primer script and run it. It will provide recommendations to several facets of your config for better performance.
Also look into adjusting your timeout values both in MySQL and PHP.
How big (file size) is the file you are importing and are you able to import the file using the mysql command line client instead of PHPMyAdmin?
If you are using MAMP on OS X, you will need to change the max_allowed_packet value in the template for MySQL.
You can find it at: File > Edit template > MySQL my.cnf
Then just search for max_allowed_packet, change the value and
save.
I had this error and other related ones, when I imported at 16 GB SQL file. For me, editing my.ini and setting the following (based on several different posts) in the [mysqld] section:
max_allowed_packet = 110M
innodb_buffer_pool_size=511M
innodb_log_file_size=500M
innodb_log_buffer_size = 800M
net_read_timeout = 600
net_write_timeout = 600
If you are running under Windows, go to the control panel, services, and look at the details for MySQL and you will see where my.ini is. Then after you edit and save my.ini, restart the mysql service (or restart the computer).
If you are using HeidiSQL, you can also set some or all of these using that.
I solved my issue with this short /etc/mysql/my.cnf file :
[mysqld]
wait_timeout = 600
max_allowed_packet = 100M
The other reason this can happen is running out of memory. Check /var/log/messages and make sure that your my.cnf is not set up to cause mysqld to allocate more memory than your machine has.
Your mysqld process can actually be killed by the kernel and then re-started by the "safe_mysqld" process without you realizing it.
Use top and watch the memory allocation while it's running to see what your headroom is.
make a backup of my.cnf before changing it.
I got same issue with
$image_base64 = base64_encode(file_get_contents($_FILES['file']['tmp_name']) );
$image = 'data:image/jpeg;base64,'.$image_base64;
$query = "insert into images(image) values('".$image."')";
mysqli_query($con,$query);
In \xampp\mysql\bin\my.ini file of phpmyadmin we get only
[mysqldump]
max_allowed_packet=110M
which is just for mysqldump -u root -p dbname . I resolved my issue by replacing above code with
max_allowed_packet=110M
[mysqldump]
max_allowed_packet=110M
I updated "max_allowed_packet" to 1024M, but it still wasn't working. It turns out my deployment script was running:
mysql --max_allowed_packet=512M --database=mydb -u root < .\db\db.sql
Be sure to explicitly specify a bigger number from the command line if you are donig it this way.
If your data includes BLOB data:
Note that an import of data from the command line seems to choke on BLOB data, resulting in the 'MySQL server has gone away' error.
To avoid this, re-create the mysqldump but with the --hex-blob flag:
http://dev.mysql.com/doc/refman/5.7/en/mysqldump.html#option_mysqldump_hex-blob
which will write out the data file with hex values rather than binary amongst other text.
PhpMyAdmin also has the option "Dump binary columns in hexadecimal notation (for example, "abc" becomes 0x616263)" which works nicely.
Note that there is a long-standing bug (as of December 2015) which means that GEOM columns are not converted:
Back up a table with a GEOMETRY column using mysqldump?
so using a program like PhpMyAdmin seems to be the only workaround (the option noted above does correctly convert GEOM columns).
If it takes a long time to fail, then enlarge the wait_timeout variable.
If it fails right away, enlarge the max_allowed_packet variable; it it still doesn't work, make sure the command is valid SQL. Mine had unescaped quotes which screwed everything up.
Also, if feasible, consider limiting the number of inserts of a single SQL command to, say, 1000. You can create a script that creates multiple statements out of a single one by reintroducing the INSERT... part every n inserts.
i got a similar error.. to solve this just open my.ini file..here at line no 36 change the value of maximum allowed packet size ie. max_allowed_packet = 20M
Make sure mysqld process does not restart because of service managers like systemd.
I had this problem in vagrant with centos 7. Configuration tweaks didn't help. Turned out it was systemd which killed mysqld service every time when it took too much memory.
I had similar error today when duplicating database (MySQL server has gone away...), but when I tried to restart mysql.server restart I got error
ERROR! The server quit without updating PID ...
This is how I solved it:
I opened up Applications/Utilities/ and ran Activity Monitor
quit mysqld
then was able to solve the error problem with
mysql.server restart
I am doing some large calculations which involves the mysql connection to stay long time and with heavy data. i was facing this "Mysql go away issue". So i tried t optimize the queries but that doen't helped me then i increased the mysql variables limit which is set to a lower value by default.
wait_timeout
max_allowed_packet
To the limit what ever suits to you it should be the Any Number * 1024(Bytes). you can login to terminal using 'mysql -u username - p' command and can check and change for these variable limits.
For GoDaddy shared hosting
On GoDaddy shared hosting accounts, it is tricky to tweak the PHP.ini etc files. However, there is another way and it just worked perfectly for me. (I just successfully uploaded a 3.8Mb .sql text file, containing 3100 rows and 145 cols. Using the IMPORT command in phpMyAdmin, I was getting the dreaded MySQL server has gone away error, and no further information.)
I found that Matt Butcher had the right answer. Like Matt, I had tried all kinds of tricks, from exporting MySQL databases in bite-sized chunks, to writing scripts that break large imports into smaller ones. But here is what worked:
(1) CPANEL ---> FILES (group) ---> BACKUP
(2a) Under "Partial Backups" heading...
(2b) Under "Download a MySQL Database Backup"
(2c) Choose your database and download a backup (this step optional, but wise)
(3a) Directly to the right of 2b, under heading "Restore a MySQL Database Backup"
(3b) Choose the .SQL import file from your local drive
(3c) True happiness will be yours (shortly....) Mine took about 5 seconds
I was able to use this method to import a single table. Nothing else in my database was affected -- but that is what step (2) above is intended to protect against.
Notes:
a. If you are unsure how to create a .SQL import file, use phpMyAdmin to export a table and modify that file structure.
SOURCE:
Matt Butcher 2010 Article
If increasing max_allowed_packet doesn't help.
I was getting the same error as you when importing a .sql file into my database via Sequel Pro.
The error still persisted after upping the max_allowed_packet to 512M so I ran the import in the command line instead with:
mysql --verbose -u root -p DatabaseName < MySQL.sql
It gave the following error:
ASCII '\0' appeared in the statement, but this is not allowed unless option --binary-mode is enabled
I found a couple helpful StackOverflow questions:
Enable binary mode while restoring a Database from an SQL dump
Mysql ERROR: ASCII '\0' while importing sql file on linux server
In my case, my .sql file was a little corrupt or something. The MySQL dump we get comes in two zip files that need to be concatenated together and then unzipped. I think the unzipping was interrupted initially, leaving the file with some odd characters and encodings. Getting a fresh MySQL dump and unzipping it properly worked for me.
Just wanted to add this here in case others find that increasing the max_allowed_packet variable was not helping.
None of the solutions regarding packet size or timeouts made any difference for me. I needed to disable ssl
mysql -u -p -hmyhost.com --disable-ssl db < file.sql
https://dev.mysql.com/doc/refman/5.7/en/encrypted-connections.html
I am storing images in MYSQL.
I have table as
CREATE TABLE myTable (id INT, myImage BLOB);
When I am trying to insert 4.7MB file, I am getting exception as
com.mysql.jdbc.PacketTooBigException: Packet for query is too large (4996552 > 1048576). You can change this value on the server by setting the max_allowed_packet' variable.
I believe this is related to image size only. Is there any other variable type that I can use?
Update 1
As per older SO question, I also tried with MEDIUMBLOB but still I am getting same error.
Adding Image to a database in Java
Update 2
At the start of the project, I execute below query and everything is working now
SET GLOBAL max_allowed_packet = 1024*1024*14;
As the error says, it has nothing to do with variable type but rather the max_allowed_packet variable:
You must increase this value if you are using large BLOB columns or long strings. It should be as big as the largest BLOB you want to use. The protocol limit for max_allowed_packet is 1GB. The value should be a multiple of 1024; nonmultiples are rounded down to the nearest multiple.
But, generally speaking, don't store files in your database - store them in your filesystem and record the path to the file in the database.
For Windows users:
mysql_home points to your mysql/mariadb installation folder.
open cmd, cd to %mysql_home%\bin and run mysqladmin > temp.txt This will spit out a lot of information about the usage of the tool. Somewhere among all that output you will find this information:
Default options are read from the following files in the given order:
C:\windows\my.ini C:\windows\my.cnf C:\my.ini C:\my.cnf c:\mariadb-5.5.29-w
inx64\my.ini c:\mariadb-5.5.29-winx64\my.cnf
This shows that you could have, if you don't have it already, a file called my.ini or my.conf in the %mysql_home% directory.
create my.ini and add the lines:
[mysqld]
#allow larger BLOBs to be stored
max_allowed_packet = 10M
make sure to include the settings group which is [mysqld] otherwise it will fail to start (and for me it ended up hanging in limbo).
You will now need to restart the MySQL daemon, this is done either by killing and starting the currently running mysqld process or by restarting the MySQL service (run services.msc, locate MySQL, press the restart button; or from cmd, net stop MySQL followed by net start MySQL).
Following worked for me
edit my.cnf file ( mine was in /etc/mysql )
Then modify the max_allowed_packet value
I set it to
max_allowed_packet=200M
Make sure you restart MySQL for change to take effect
If working with AWS RDS, max_allowed_packet can be modified using DB Parameter Groups
The max_allowed_packet variable has a default value set in the configuration file (my.ini in my case). If your application tries to execute a query whose packet size exceeds this value, this exception is thrown.
My setup is on a Windows 10 machine with MySQL Server 8.0.
I copied the my.ini file with my desired value (64M) for max_allowed_packet to the various possible locations (C:\my.ini, C:\Windows\my.ini). Then restarted the mysql server. It didn't work. When I queried the database for the max_allowed_packet variable, the value remained unchanged.
The following steps worked:
I discovered that there is a my.ini file at a different location.
Open the my.ini file at the following location C:\ProgramData\MySQL\MySQL Server 8.0. This has lots of entries, besides max_allowed_packet.
Locate the entry for max_allowed_packet, and set it to the desired value (for e.g. 64M).
Save and close the my.ini file.
Restart the MySQL80 service.
Log into to the mysql server prompt and run the query
show variables like 'max_allowed_packet';
You should see the value set to your desired value.
I have been trying for quite a while to import a large (4GB) sql dump file with the MySQL command line. I always get a "MySQL server has gone away" error at a particular line, or if I split the file into smaller chunks (about 512 MB), I get an error about the maximum allowed packet size exceeded, again around the same line. From what I have read, the solution is to change the max_allowed_packet size in my.ini to a large number and restart, but I have done so with no luck. I have also tried the import using the command line parameter, --max_allowed_packet=2147483648, no luck there either. Is there something else that I am missing here? I've exhausted all of the other forum suggestions, maybe someone has another idea I can try. Thanks,
JW
Also, you have to change it for both the client and the daemon mysqld server. Change the my.cnf or my.ini file under the [mysqld] section and set max_allowed_packet=1000M or you could run these commands in a MySQL console connected to that same server:
set global net_buffer_length=1000000000;
set global max_allowed_packet=1000000000;
Use a very large value for the packet size, because they are in bytes and then restart your MySQL server.
I got the Error Code: 2013. Lost connection to MySQL server during query error when I tried to add an index to a table using MySQL Workbench.
I noticed also that it appears whenever I run long query.
Is there away to increase the timeout value?
New versions of MySQL WorkBench have an option to change specific timeouts.
For me it was under Edit → Preferences → SQL Editor → DBMS connection read time out (in seconds): 600
Changed the value to 6000.
Also unchecked limit rows as putting a limit in every time I want to search the whole data set gets tiresome.
If your query has blob data, this issue can be fixed by applying a my.ini change as proposed in this answer:
[mysqld]
max_allowed_packet=16M
By default, this will be 1M (the allowed maximum value is 1024M). If the supplied value is not a multiple of 1024K, it will automatically be rounded to the nearest multiple of 1024K.
While the referenced thread is about the MySQL error 2006, setting the max_allowed_packet from 1M to 16M did fix the 2013 error that showed up for me when running a long query.
For WAMP users: you'll find the flag in the [wampmysqld] section.
Start the DB server with the comandline option net_read_timeout / wait_timeout and a suitable value (in seconds) - for example: --net_read_timeout=100.
For reference see here and here.
SET ##local.net_read_timeout=360;
Warning: The following will not work when you are applying it in remote connection:
SET ##global.net_read_timeout=360;
Edit: 360 is the number of seconds
Add the following into /etc/mysql/cnf file:
innodb_buffer_pool_size = 64M
example:
key_buffer = 16M
max_allowed_packet = 16M
thread_stack = 192K
thread_cache_size = 8
innodb_buffer_pool_size = 64M
In my case, setting the connection timeout interval to 6000 or something higher didn't work.
I just did what the workbench says I can do.
The maximum amount of time the query can take to return data from the DBMS.Set 0 to skip the read timeout.
On Mac
Preferences -> SQL Editor -> Go to MySQL Session -> set connection read timeout interval to 0.
And it works 😄
There are three likely causes for this error message
Usually it indicates network connectivity trouble and you should check the condition of your network if this error occurs frequently
Sometimes the “during query” form happens when millions of rows are being sent as part of one or more queries.
More rarely, it can happen when the client is attempting the initial connection to the server
For more detail read >>
Cause 2 :
SET GLOBAL interactive_timeout=60;
from its default of 30 seconds to 60 seconds or longer
Cause 3 :
SET GLOBAL connect_timeout=60;
You should set the 'interactive_timeout' and 'wait_timeout' properties in the mysql config file to the values you need.
Just perform a MySQL upgrade that will re-build innoDB engine along with rebuilding of many tables required for proper functioning of MySQL such as performance_schema, information_schema, etc.
Issue the below command from your shell:
sudo mysql_upgrade -u root -p
If you experience this problem during the restore of a big dump-file and can rule out the problem that it has anything to do with network (e.g. execution on localhost) than my solution could be helpful.
My mysqldump held at least one INSERT that was too big for mysql to compute. You can view this variable by typing show variables like "net_buffer_length"; inside your mysql-cli.
You have three possibilities:
increase net_buffer_length inside mysql -> this would need a server restart
create dump with --skip-extended-insert, per insert one line is used -> although these dumps are much nicer to read this is not suitable for big dumps > 1GB because it tends to be very slow
create dump with extended inserts (which is the default) but limit the net-buffer_length e.g. with --net-buffer_length NR_OF_BYTES where NR_OF_BYTES is smaller than the server's net_buffer_length -> I think this is the best solution, although slower no server restart is needed.
I used following mysqldump command:
mysqldump --skip-comments --set-charset --default-character-set=utf8 --single-transaction --net-buffer_length 4096 DBX > dumpfile
On the basis of what I have understood this error was caused due to read timeout and max allowed packet default is 4M. if your query file more than 4Mb then you get an error. this worked for me
change the read timeout. For changing go to Workbench Edit → Preferences → SQL Editor
2. change the max_allowed_packet manually by editing the file my.ini. for editing go to "C:\ProgramData\MySQL\MySQL Server 8.0\my.ini". The folder ProgramData folder is hidden so if you did not see then select show hidden file in view settings. set the max_allowed_packet = 16M in my.ini file.
3. Restart MySQL. for restarting go to win+ R -> services.msc and restart MySQL.
I know its old but on mac
1. Control-click your connection and choose Connection Properties.
2. Under Advanced tab, set the Socket Timeout (sec) to a larger value.
Sometimes your SQL-Server gets into deadlocks, I've been in to this problem like 100 times. You can either restart your computer/laptop to restart server (easy way) OR you can go to task-manager>services>YOUR-SERVER-NAME(for me , it was MySQL785 something like this). And right-click > restart.
Try executing query again.
Try please to uncheck limit rows in in Edit → Preferences →SQL Queries
because You should set the 'interactive_timeout' and 'wait_timeout' properties in the mysql config file to the values you need.
Change "read time out" time in Edit->Preferences->SQL editor->MySQL session
I got the same issue when loading a .csv file.
Converted the file to .sql.
Using below command I manage to work around this issue.
mysql -u <user> -p -D <DB name> < file.sql
Hope this would help.
If all the other solutions here fail - check your syslog (/var/log/syslog or similar) to see if your server is running out of memory during the query.
Had this issue when innodb_buffer_pool_size was set too close to physical memory without a swapfile configured. MySQL recommends for a database specific server setting innodb_buffer_pool_size at a max of around 80% of physical memory, I had it set to around 90%, the kernel was killing the mysql process. Moved innodb_buffer_pool_size back down to around 80% and that fixed the issue.
Go to Workbench Edit → Preferences → SQL Editor → DBMS connections read time out : Up to 3000.
The error no longer occurred.
I faced this same issue. I believe it happens when you have foreign keys to larger tables (which takes time).
I tried to run the create table statement again without the foreign key declarations and found it worked.
Then after creating the table, I added the foreign key constrains using ALTER TABLE query.
Hope this will help someone.
This happened to me because my innodb_buffer_pool_size was set to be larger than the RAM size available on the server. Things were getting interrupted because of this and it issues this error. The fix is to update my.cnf with the correct setting for innodb_buffer_pool_size.
Go to:
Edit -> Preferences -> SQL Editor
In there you can see three fields in the "MySQL Session" group, where you can now set the new connection intervals (in seconds).
Turns out our firewall rule was blocking my connection to MYSQL. After the firewall policy is lifted to allow the connection i was able to import the schema successfully.
I had the same problem - but for me the solution was a DB user with too strict permissions.
I had to allow the Execute ability on the mysql table. After allowing that I had no dropping connections anymore
Check if the indexes are in place first.
SELECT *
FROM INFORMATION_SCHEMA.STATISTICS
WHERE TABLE_SCHEMA = '<schema>'
I ran into this while running a stored proc- which was creating lots of rows into a table in the database.
I could see the error come right after the time crossed the 30 sec boundary.
I tried all the suggestions in the other answers. I am sure some of it helped , however- what really made it work for me was switching to SequelPro from Workbench.
I am guessing it was some client side connection that I could not spot in Workbench.
Maybe this will help someone else as well ?
If you are using SQL Work Bench, you can try using Indexing, by adding an index to your tables, to add an index, click on the wrench(spanner) symbol on the table, it should open up the setup for the table, below, click on the index view, type an index name and set the type to index, In the index columns, select the primary column in your table.
Do the same step for other primary keys on other tables.
There seems to be an answer missing here for those using SSH to connect to their MySQL database. You need to check two places not 1 as suggested by other answers:
Workbench Edit → Preferences → SQL Editor → DBMS
Workbench Edit → Preferences → SSH → Timeouts
My default SSH Timeouts were set very low and causing some (but apparently not all) of my timeout issues. After, don't forget to restart MySQL Workbench!
Last, it may be worth contacting your DB Admin and asking them to increase wait_timeout & interactive_timeout properties in mysql itself via my.conf + mysql restart or doing a global set if restarting mysql is not an option.
Hope this helps!
Three things to be followed and make sure:
Whether multiple queries show lost connection?
how you use set query in MySQL?
how delete + update query simultaneously?
Answers:
Always try to remove definer as MySQL creates its own definer and if multiple tables involved for updation try to make a single query as sometimes multiple query shows lost connection
Always SET value at the top but after DELETE if its condition doesn't involve SET value.
Use DELETE FIRST THEN UPDATE IF BOTH OF THEM OPERATIONS ARE PERFORMED ON DIFFERENT TABLES
I had this error message due to a problem after of upgrade Mysql. The error appeared immediately after I tried to do any query
Check mysql error log files in path /var/log/mysql (linux)
In my case reassigning Mysql owner to the Mysql system folder worked for me
chown -R mysql:mysql /var/lib/mysql
Establish connection first
mysql --host=host.com --port=3306 -u username -p
then select your db use dbname
then source dumb source C:\dumpfile.sql.
After it's done \q