How to confirm MySQL or MariaDB slave status

When you want to check MySQL or MariaDB slave status, run the below command

[linux ~]$ show slave status\G;
************ 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: ***
                  Master_User: ***
                  Master_Port: ****
                Connect_Retry: 60
              Master_Log_File: sm-bin.*****
          Read_Master_Log_Pos: *****
               Relay_Log_File: db104-relay-bin.****
                Relay_Log_Pos: 287813229
        Relay_Master_Log_File: sm-bin.****
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
              Replicate_Do_DB:
          Replicate_Ignore_DB:
           Replicate_Do_Table:
       Replicate_Ignore_Table:
      Replicate_Wild_Do_Table:
  Replicate_Wild_Ignore_Table:
                   Last_Errno: 0
                   Last_Error:
                 Skip_Counter: 0
          Exec_Master_Log_Pos: ******
              Relay_Log_Space: ******
              Until_Condition: None
               Until_Log_File:
                Until_Log_Pos: 0
           Master_SSL_Allowed: No
           Master_SSL_CA_File:
           Master_SSL_CA_Path:
              Master_SSL_Cert:
            Master_SSL_Cipher:
               Master_SSL_Key:
        Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert: No
                Last_IO_Errno: 0
                Last_IO_Error:
               Last_SQL_Errno: 0
               Last_SQL_Error:
  Replicate_Ignore_Server_Ids:
             Master_Server_Id: ******
               Master_SSL_Crl:
           Master_SSL_Crlpath:

**************abbreviation**************

If you want to whether slave works well or not, check these status.
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
Also, there is no error displayed on slave status, slave is no problem to work..

Regarding the meanings of respective parameters, refer the official documents
https://dev.mysql.com/doc/refman/5.7/en/show-slave-status.html
https://mariadb.com/kb/en/library/show-slave-status/

How to use ssh-keygen

Brief
Surmise about ssh-keygen

What is ssh-keygen?
create ssh key pairs, a secret key and a public key

Environment 
CentOS

Basic Syntax
ssh-keygen <options>

e.g.
# create a secret key and a public key
# The keys are created in the folder of /root/.ssh/ at the default
ssh-keygen -t 'algorithm name' -m 'comment'

# create a public key from a secret key
ssh-keygen -yf ${private_key_file} > ${public_key_file}