Start, close and view MySQL service (Linux)

1. see MySQL Status of the service

[[email protected] ~]$ systemctl status mysqld.service
● mysqld.service - MySQL Server
   Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
   Active: active (running) since  5、 ... and  2022-07-15 09:33:30 CST; 43min ago
     Docs: man:mysqld(8)
           http://dev.mysql.com/doc/refman/en/using-systemd.html
  Process: 1370 ExecStart=/usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid $MYSQLD_OPTS (code=exited, status=0/SUCCESS)
  Process: 989 ExecStartPre=/usr/bin/mysqld_pre_systemd (code=exited, status=0/SUCCESS)
 Main PID: 1374 (mysqld)
   CGroup: /system.slice/mysqld.service
           └─1374 /usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid

7 month  15 09:33:26 hadoop102 systemd[1]: Starting MySQL Server...
7 month  15 09:33:30 hadoop102 systemd[1]: Started MySQL Server.

2. close MySQL service

[[email protected] ~]$ sudo systemctl stop mysqld.service

[[email protected] ~]$ systemctl status mysqld.service
● mysqld.service - MySQL Server
   Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
   Active: inactive (dead) since  5、 ... and  2022-07-15 10:22:53 CST; 2s ago
     Docs: man:mysqld(8)
           http://dev.mysql.com/doc/refman/en/using-systemd.html
  Process: 5101 ExecStart=/usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid $MYSQLD_OPTS (code=exited, status=0/SUCCESS)
  Process: 5079 ExecStartPre=/usr/bin/mysqld_pre_systemd (code=exited, status=0/SUCCESS)
 Main PID: 5104 (code=exited, status=0/SUCCESS)

7 month  15 10:22:34 hadoop102 systemd[1]: Starting MySQL Server...
7 month  15 10:22:35 hadoop102 systemd[1]: Started MySQL Server.
7 month  15 10:22:52 hadoop102 systemd[1]: Stopping MySQL Server...
7 month  15 10:22:53 hadoop102 systemd[1]: Stopped MySQL Server.

3. start-up MySQL service

[[email protected] ~]$ sudo systemctl start mysqld.service

[[email protected] ~]$ systemctl status mysqld.service
● mysqld.service - MySQL Server
   Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
   Active: active (running) since  5、 ... and  2022-07-15 10:24:00 CST; 2s ago
     Docs: man:mysqld(8)
           http://dev.mysql.com/doc/refman/en/using-systemd.html
  Process: 5195 ExecStart=/usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid $MYSQLD_OPTS (code=exited, status=0/SUCCESS)
  Process: 5169 ExecStartPre=/usr/bin/mysqld_pre_systemd (code=exited, status=0/SUCCESS)
 Main PID: 5198 (mysqld)
   CGroup: /system.slice/mysqld.service
           └─5198 /usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid

7 month  15 10:24:00 hadoop102 systemd[1]: Starting MySQL Server...
7 month  15 10:24:00 hadoop102 systemd[1]: Started MySQL Server.

4. Set to MySQL Boot up service ( Suggest )

[[email protected] ~]$ sudo systemctl enable mysqld.service

5. Check whether the self startup has been set successfully

[[email protected] ~]$ systemctl list-unit-files | grep mysqld
mysqld.service                                enabled 
mysqld[email protected]                               disabled

6. close MySQL Boot up service

[[email protected] ~]$ sudo systemctl disable mysqld.service
Removed symlink /etc/systemd/system/multi-user.target.wants/mysqld.service.

[[email protected] ~]$ systemctl list-unit-files | grep mysqld
mysqld.service                                disabled
[email protected]                               disabled

7. restart MySQL service

[[email protected] hive-3.1.2]$ sudo systemctl restart mysqld.service