Why is MySql database not working?

Question

PHP

On the server where I have a VPS yesterday, a DDOS attack was carried out and failures occurred. After that, MySql stopped working for me.
phpmyadmin:

#2002 Unable to connect to MySQL server
Error while specifying connection for controluser in configuration.

PDO:

SQLSTATE[HY000] [2002] Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)

Support says that these are my problems, they say, and decide for yourself.
What to do? And how to make a backup if you have to reinstall MySql?

Answer 1

The first thing to do is to restart the server:
After the reboot, see if mysql has loaded:
If mysql has not loaded, then look in the logs for the reason why it did not load:

/var/log/mysql/error.log
/var/log/syslog
/var/log/messages
sometimes /var/lib/mysql/error.log

If mysql has loaded try to connect from the console:
If the connection was successful, exit the console client "quit" check if the socket has been created in the directory /var/run/mysqld/mysqld.sock If
the socket is not in the directory, you need to search for it with the command:
directory other than /var/run/mysqld/mysqld.sock, you need to specify a new socket location in the php.ini settings:

pdo_mysql.default_socket=
mysql.default_socket =
mysqli.default_socket =

Answer 2

Maybe just restart MySQL?
It looks like it is not running or has crashed.

Answer 3

Get an admin. You can guess for a long time.

Answer 4

See error log, presumably in /var/db/mysql file with .err resolution

Answer 5

I had the same problem, I suffered for a long time, in the end I realized that mysqld.exe did not start.
I realized that you need to start the unpacked server using the command line:
to shut down the server, use:
These exe files are located in the folder with your server in the bin directory.
You can also try installing MySQLInstaller to work with the MySQL server , it can replace the unpacking of the server from the archive with an installation with a convenient interface.
HERE IS THE LINK TO MySQLInstaller : dev.mysql.com/downloads/windows/installer/5.6.html
(On the site, at first it seems that you can’t install without registration, but there is a button below " No thanks, just start my download .")
+
(It is indicated that MySQLInstaller is 32-bit, but later you can install 64-bit server in the same program)

Answer 6

Create this file:

sudo mkdir /var/run/mysqld
sudo mkfifo /var/run/mysqld/mysqld.sock
sudo chown -R mysql /var/run/mysqld

Check: mysql -u root -p
It will most likely give a permissions error. Disable ban for "root" user:

$ sudo -i
$ echo "update user set plugin='' where User='root'; flush privileges;" | mysql -u root -p mysql

Restart mysql: sudo service mysql restart
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