I cannot start Mysql

enrico.rubagotti 2019-11-12 18:08:02 UTC #1

Keywords: MySQL - AWS - Technical issue - Other
bnsupport ID: 06c90d15-ff2f-0b15-a1ef-369af73979b8
Description:
Since when Ioaded > 8 Gbyte of data Mysql behave erratically and I cannot start it at the moment.

bitnami@ip-172-31-46-39:~$ sudo /opt/bitnami/ctlscript.sh start mysql
/opt/bitnami/mysql/scripts/ctl.sh : mysql could not be started
There is spare HD space:

bitnami@ip-172-31-46-39:~$
bitnami@ip-172-31-46-39:~$ df -h
Filesystem Size Used Avail Use% Mounted on
udev 3.9G 0 3.9G 0% /dev
tmpfs 799M 8.9M 790M 2% /run
/dev/xvda1 194G 38G 157G 20% /
tmpfs 3.9G 0 3.9G 0% /dev/shm
tmpfs 5.0M 0 5.0M 0% /run/lock
tmpfs 3.9G 0 3.9G 0% /sys/fs/cgroup
/dev/loop0 90M 90M 0 100% /snap/core/8039
/dev/loop1 13M 13M 0 100% /snap/amazon-ssm-agent/295
/dev/loop2 90M 90M 0 100% /snap/core/7917
/dev/loop3 18M 18M 0 100% /snap/amazon-ssm-agent/1480
tmpfs 1.6G 0 1.6G 0% /mnt/hardDisk
/dev/xvdj 500G 76G 425G 16% /mnt/xvdj
tmpfs 799M 0 799M 0% /run/user/1000
Ido not have any active mysql process before to try to start it:

When I run
ps aux | grep mysql
bitnami 20039 0.0 0.0 14220 924 pts/0 S+ 18:01 0:00 grep --color=auto mysql

But when I run
sudo /opt/bitnami/ctlscript.sh start mysql

I obtained the following error :

/opt/bitnami/mysql/scripts/ctl.sh : mysql could not be started
Monitored mysql
bitnami@ip-172-31-46-39:~$ ps aux | grep mysql
root 20053 0.0 0.0 4500 1688 pts/0 S 18:03 0:00 /bin/sh /opt/bitnami/mysql/bin/mysqld_safe --defaults-file=/opt/bitnami/mysql/my.cnf --mysqld=mysqld.bin --socket=/opt/bitnami/mysql/tmp/mysql.sock --datadir=/opt/bitnami/mysql/data --log-error=/opt/bitnami/mysql/data/mysqld.log --pid-file=/opt/bitnami/mysql/data/mysqld.pid --lower-case-table-names=1
mysql 20456 8.3 4.4 990888 367164 pts/0 Sl 18:03 0:12 /opt/bitnami/mysql/bin/mysqld.bin --defaults-file=/opt/bitnami/mysql/my.cnf --basedir=/opt/bitnami/mysql --datadir=/opt/bitnami/mysql/data --plugin-dir=/opt/bitnami/mysql/lib/plugin --user=mysql --lower-case-table-names=1 --log-error=/opt/bitnami/mysql/data/mysqld.log --pid-file=/opt/bitnami/mysql/data/mysqld.pid --socket=/opt/bitnami/mysql/tmp/mysql.sock --port=3306
bitnami 20557 0.0 0.0 14220 940 pts/0 S+ 18:06 0:00 grep --color=auto mysql

The support bundle code is: 06c90d15-ff2f-0b15-a1ef-369af73979b8

michiel 2019-11-13 09:55:34 UTC #2

Hi @enrico.rubagotti,

Your instance doesn't seem to have a lot of free memory available (158M). This is a probable cause of MySQL not starting. Could you check if enabling swap memory solves the issue?

https://docs.bitnami.com/general/how-to/troubleshoot-magento-issues/#does-your-instance-have-swap-memory-enabled

Regards,
Michiel

enrico.rubagotti 2019-11-13 17:01:11 UTC #3

Dear Michiel,
I really appreciate your help.

I increased the RAM to 32 Gigabyte and uses swap and now the mysql is working
Unfortunately I cannot export the data using :
bitnami@ip-172-31-46-39:~$ sudo mysqldump --force --add-drop-table -u root -pXXXXXXX --log-error= /mnt/xvdj/log.mysqldump -v csv_data >csv_data.sql
mysqldump: [Warning] Using a password on the command line interface can be insecure.
The output file results empty:
bitnami@ip-172-31-46-39:~$ ls -lht
total 16K
-rw-r--r-- 1 bitnami bitnami 0 Nov 13 16:45 csv_data.sql
-r-------- 1 bitnami bitnami 395 Nov 13 15:58 bitnami_credentials
-rwxr-xr-x 1 bitnami bitnami 405 Nov 12 17:58 kill.sh
-rwxr-xr-x 1 bitnami bitnami 855 Nov 12 08:20 start.sh
drwxr-xr-x 2 bitnami bitnami 4.0K Oct 28 13:47 document
lrwxrwxrwx 1 bitnami bitnami 12 Oct 26 05:51 stack -> /opt/bitnami
lrwxrwxrwx 1 bitnami bitnami 27 Oct 26 05:51 htdocs -> /opt/bitnami/apache2/htdocs
lrwxrwxrwx 1 bitnami bitnami 17 Oct 26 05:51 apps -> /opt/bitnami/apps

I do not have any mysqldump active process:

bitnami@ip-172-31-46-39:~$ ps aux | grep mysqldump
bitnami 5800 0.0 0.0 14220 980 pts/1 S+ 16:47 0:00 grep --color=auto mysqldump

Support ticket: e7d3b2fa-f147-5c3d-6b11-08d6ea61cb22

Your help will be highly appreciated

michiel 2019-11-14 09:16:27 UTC #4

Hi @enrico.rubagotti,

You need to provide the applications database name. For example:

mysqldump -u root -p bitnami_app > backup.sql

You can find more information about exporting data in the following guide:

https://docs.bitnami.com/general/infrastructure/lamp/administration/backup-restore-mysql-mariadb/

Regards,
Michiel

enrico.rubagotti 2019-11-14 11:10:42 UTC #5

Hi Michael,
thanks but I supplied the database name:

nohup sudo mysqldump --force --add-drop-table -u User -py234324 csv_data > /mnt/hardDisk/csv_data.sql &

It exists with error 2 and each time it exports a table throws the following error:

mysqldump: Couldn't execute 'show table status like 'w10_0_cia'': MySQL server has gone away (2006)

Why it cannot connect with the mysql server ?

gongomgra 2019-11-15 12:56:27 UTC #6

Hi @enrico.rubagotti,

Was the MySQL process still running after receiving that error? It is possible that you are trying to get a very big packet from the server and it is giving an error

https://dev.mysql.com/doc/refman/8.0/en/packet-too-large.html

Can you try is increasing the max_allowed_packet parameter of MySQL helps you to fix your issue as mentioned in the link below? Try increasing it for both sections of the my.cnf file: mysqld and client.

Also, can you tell us which User are you setting in the mysqldump command? Can you try using root so you are sure that you have full privileges and the MySQL system?

Remember to restart the MySQL service for changes to take effect

sudo /opt/bitnami/ctlscript.sh restart mysql

Please run the bnsupport tool again in case of errors so we can check your updated configuration and logs.

Hope it helps,
Gonzalo

Bitnami provides free all-in-one installers, virtual machines and cloud images for popular open source applications. Get them now!