1、环境描述
MariaDB 10.1.35
CentOS 6.8

2、stop slave命令

root@MariaDB0 07:55:  [(none)]> help stop
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id:    21
Current database: *** NONE ***

Name: 'STOP SLAVE'
Description:
Syntax:
STOP SLAVE [thread_types]

thread_types:
    [thread_type [, thread_type] ... ]

thread_type: IO_THREAD | SQL_THREAD

Stops the slave threads. STOP SLAVE requires the SUPER privilege.
Recommended best practice is to execute STOP SLAVE on the slave before
stopping the slave server (see
http://dev.mysql.com/doc/refman/5.5/en/server-shutdown.html, for more
information).

When using the row-based logging format: You should execute STOP SLAVE
on the slave prior to shutting down the slave server if you are
replicating any tables that use a nontransactional storage engine (see
the Note later in this section). In MySQL 5.5.9 and later, you can also
use STOP SLAVE SQL_THREAD for this purpose.

Like START SLAVE, this statement may be used with the IO_THREAD and
SQL_THREAD options to name the thread or threads to be stopped.

*Note*: In MySQL 5.5, STOP SLAVE waits until the current replication
event group affecting one or more non-transactional tables has finished
executing (if there is any such replication group), or until the user
issues a KILL QUERY or KILL CONNECTION statement. (Bug #319, Bug
#38205)

URL: https://mariadb.com/kb/en/stop-slave/

root@MariaDB0 09:07:  [(none)]> 
root@MariaDB0 09:07:  [(none)]> show slave status\G;
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.56.101
                  Master_User: repl
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000005
          Read_Master_Log_Pos: 335
               Relay_Log_File: relay-bin.000015
                Relay_Log_Pos: 627
        Relay_Master_Log_File: mysql-bin.000005
             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: 335
              Relay_Log_Space: 5452
              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: 1
               Master_SSL_Crl: 
           Master_SSL_Crlpath: 
                   Using_Gtid: No
                  Gtid_IO_Pos: 
      Replicate_Do_Domain_Ids: 
  Replicate_Ignore_Domain_Ids: 
                Parallel_Mode: conservative
1 row in set (0.00 sec)

ERROR: No query specified

root@MariaDB0 09:07:  [(none)]> stop slave io_thread;
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id:    22
Current database: *** NONE ***

Query OK, 0 rows affected (0.01 sec)

root@MariaDB0 09:09:  [(none)]> stop slave sql_thread;
Query OK, 0 rows affected (0.00 sec)

root@MariaDB0 09:09:  [(none)]> start slave io_thread;
Query OK, 0 rows affected (0.00 sec)

root@MariaDB0 09:10:  [(none)]> start slave sql_thread;
Query OK, 0 rows affected (0.00 sec)

root@MariaDB0 09:10:  [(none)]> show slave status\G;
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.56.101
                  Master_User: repl
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000005
          Read_Master_Log_Pos: 335
               Relay_Log_File: relay-bin.000016
                Relay_Log_Pos: 541
        Relay_Master_Log_File: mysql-bin.000005
             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: 335
              Relay_Log_Space: 6040
              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: 1
               Master_SSL_Crl: 
           Master_SSL_Crlpath: 
                   Using_Gtid: No
                  Gtid_IO_Pos: 
      Replicate_Do_Domain_Ids: 
  Replicate_Ignore_Domain_Ids: 
                Parallel_Mode: conservative
1 row in set (0.00 sec)

ERROR: No query specified

root@MariaDB0 09:10:  [(none)]> stop slave;
Query OK, 0 rows affected (0.00 sec)

root@MariaDB0 09:10:  [(none)]> start slave;
Query OK, 0 rows affected (0.00 sec)

root@MariaDB0 09:10:  [(none)]>