[Solved] CentOS installs MySQL and starts MySQL with error 2002 (HY000)

MYSQL Startup error: ERROR 2002 (HY000): Can’t connect to local MySQL server through socket ‘/var/lib/mysql/mysql.sock’ (111)

[[email protected] ~]# sudo service mysqld status
Redirecting to /bin/systemctl status mysqld.service
● mysqld.service - MySQL Community Server
   Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
   Active: inactive (dead)
[[email protected] ~]# mysqladmin -u root password '123456'
mysqladmin: connect to server at 'localhost' failed
error: 'Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)'
Check that mysqld is running and that the socket: '/var/lib/mysql/mysql.sock' exists!
[[email protected] ~]# sudo mysqladmin -u root password '123456'
mysqladmin: connect to server at 'localhost' failed
error: 'Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)'
Check that mysqld is running and that the socket: '/var/lib/mysql/mysql.sock' exists!
[[email protected] ~]# mysql -u root
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)
[[email protected] ~]# lsof -i:3306
-bash: lsof: command not found
[[email protected] ~]# mysql -uroot -h 127.0.0.1 -p
Enter password: 
ERROR 2003 (HY000): Can't connect to MySQL server on '127.0.0.1' (111)
[[email protected] ~]# mysql -uroot -h 127.0.0.1 -p
Enter password: 
ERROR 2003 (HY000): Can't connect to MySQL server on '127.0.0.1' (111)
[[email protected]n7f2wrecqn5249Z ~]# netstat -ntlp 
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name    
tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      950/sshd            
tcp        0      0 127.0.0.1:25            0.0.0.0:*               LISTEN      969/master          
tcp6       0      0 ::1:25                  :::*                    LISTEN      969/master          
[[email protected] ~]# service mysqld start
Redirecting to /bin/systemctl start mysqld.service
[[email protected] ~]# service mysqld status
Redirecting to /bin/systemctl status mysqld.service
● mysqld.service - MySQL Community Server
   Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
   Active: active (running) since Mon 2021-11-01 19:27:48 CST; 14s ago
  Process: 1724 ExecStartPost=/usr/bin/mysql-systemd-start post (code=exited, status=0/SUCCESS)
  Process: 1664 ExecStartPre=/usr/bin/mysql-systemd-start pre (code=exited, status=0/SUCCESS)
 Main PID: 1723 (mysqld_safe)
   CGroup: /system.slice/mysqld.service
           ├─1723 /bin/sh /usr/bin/mysqld_safe --basedir=/usr
           └─1890 /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib64/mysql/plugin --log-error=/var/log/mysqld.log --pid-file=/var/run/mysqld/mysqld.pid --socket=/var/...

Nov 01 19:27:47 iZ2zei01n7f2wrecqn5249Z mysql-systemd-start[1664]: Support MySQL by buying support/licenses at http://shop.mysql.com
Nov 01 19:27:47 iZ2zei01n7f2wrecqn5249Z mysql-systemd-start[1664]: Note: new default config file not created.
Nov 01 19:27:47 iZ2zei01n7f2wrecqn5249Z mysql-systemd-start[1664]: Please make sure your config file is current
Nov 01 19:27:47 iZ2zei01n7f2wrecqn5249Z mysql-systemd-start[1664]: WARNING: Default config file /etc/my.cnf exists on the system
Nov 01 19:27:47 iZ2zei01n7f2wrecqn5249Z mysql-systemd-start[1664]: This file will be read by default by the MySQL server
Nov 01 19:27:47 iZ2zei01n7f2wrecqn5249Z mysql-systemd-start[1664]: If you do not want to use this, either remove it, or use the
Nov 01 19:27:47 iZ2zei01n7f2wrecqn5249Z mysql-systemd-start[1664]: --defaults-file argument to mysqld_safe when starting the server
Nov 01 19:27:47 iZ2zei01n7f2wrecqn5249Z mysqld_safe[1723]: 211101 19:27:47 mysqld_safe Logging to '/var/log/mysqld.log'.
Nov 01 19:27:47 iZ2zei01n7f2wrecqn5249Z mysqld_safe[1723]: 211101 19:27:47 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql
Nov 01 19:27:48 iZ2zei01n7f2wrecqn5249Z systemd[1]: Started MySQL Community Server.

Start it.

service mysqld start

Recheck status

service mysqld status

Just as shown above
set the password

mysqladmin -u root password '123456'

Sign in

mysql -u root -p

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