There are two types of replication.
- Master-Master - Both databases are masters, meaning both can be used for reading and writing.
- Master-Slave - One database is the master, the other is the slave. Only the master can read and write, the slave can only read.
The start slave command can be used to start the slave database. This assume you are able to log into your MariaDB or mySQL server or you have configured passwordless authentication and will be using the -e command line option.
mysql -e "start slave"
The show slave status command can be used to display the status of the slave. Notice in this example that Slave_IO_Running and Slave_SQL_Running are Yes, which means the slave is running.
~]# mysql -e "show slave status \G" *************************** 1. row *************************** Slave_IO_State: Waiting for source to send event Master_Host: server1.example.com Master_User: replication_user Master_Port: 3306 Connect_Retry: 100 Master_Log_File: binary-log.000001 Read_Master_Log_Pos: 156 Relay_Log_File: relay-bin.000002 Relay_Log_Pos: 373 Relay_Master_Log_File: binary-log.000001 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: 156 Relay_Log_Space: 579 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: 2 Master_UUID: 0ea5da70-0481-11ec-9cef-96f1f3f0d86b Master_Info_File: mysql.slave_master_info SQL_Delay: 0 SQL_Remaining_Delay: NULL Slave_SQL_Running_State: Replica has read all relay log; waiting for more updates Master_Retry_Count: 86400 Master_Bind: Last_IO_Error_Timestamp: Last_SQL_Error_Timestamp: Master_SSL_Crl: Master_SSL_Crlpath: Retrieved_Gtid_Set: Executed_Gtid_Set: 6006451a-022c-11ec-9da1-98799582ca6f:1-50246 Auto_Position: 1 Replicate_Rewrite_DB: Channel_Name: Master_TLS_Version: Master_public_key_path: Get_master_public_key: 1 Network_Namespace: