MySQL复制优点、原理详解

mysql> show processlist\G; 
*************************** 1. row *************************** 
   Id: 3 
  User: root 
  Host: 10.24.33.187:54194 
   db: NULL 
Command: Sleep 
  Time: 176 
 State:  
  Info: NULL 
*************************** 2. row *************************** 
   Id: 4 
  User: root 
  Host: 10.24.33.187:54195 
   db: NULL 
Command: Sleep 
  Time: 176 
 State:  
  Info: NULL 
*************************** 3. row *************************** 
   Id: 8 
  User: root 
  Host: localhost 
   db: test 
Command: Query 
  Time: 0 
 State: starting 
  Info: show processlist 
*************************** 4. row *************************** 
   Id: 12 
  User: repl 
  Host: dsz884.hcg.homecredit.net:39731 
   db: NULL 
Command: Binlog Dump  --Binlog Dump线程 
  Time: 87 
 State: Master has sent all binlog to slave; waiting for more updates --由此可见，以“推送”的方式同步 
  Info: NULL 
4 rows in set (0.00 sec) 
 
ERROR:  
No query specified 

mysql> show processlist\G; 
*************************** 1. row *************************** 
   Id: 1 
  User: system user 
  Host:  
   db: NULL 
Command: Connect 
  Time: 4427 
 State: Waiting for master to send event 
  Info: NULL 
*************************** 2. row *************************** 
   Id: 2 
  User: system user 
  Host:  
   db: NULL 
Command: Connect 
  Time: 2044 
 State: Slave has read all relay log; waiting for more updates 
  Info: NULL 

mysql> show variables like '%binlog_format%'; 
+---------------+-------+ 
| Variable_name | Value | 
+---------------+-------+ 
| binlog_format | ROW  | 
+---------------+-------+ 
1 row in set (0.00 sec) 

mysql> show slave status \G; 
*************************** 1. row *************************** 
        Slave_IO_State: Waiting for master to send event 
         Master_Host: 10.24.33.186 --主库IP 
         Master_User: repl --主库用于主从复制的用户账号 
         Master_Port: 3306 --主库端口 
        Connect_Retry: 60  
       Master_Log_File: mysql-bin.000005 --从库I/O线程当前读取主库Binlog文件名 
     Read_Master_Log_Pos: 4356 --从库I/O线程读取主库Binlog的位置 
        Relay_Log_File: strong-relay-bin.000006 --SQL线程正在应用的Relay Log 
        Relay_Log_Pos: 320 --Relay Log的位置 
    Relay_Master_Log_File: mysql-bin.000005 --Relay Log对应的Binlog 
       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: 4356 --SQL线程正在应用Relay Log的位置对应的Binlog的位置 
       Relay_Log_Space: 1153 
       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_UUID: 2a3e3fd9-0587-11e8-bdb8-0800272325a8 
       Master_Info_File: /usr/local/mysql-5.7.21-el7-x86_64/data/master.info 
          SQL_Delay: 0 
     SQL_Remaining_Delay: NULL 
   Slave_SQL_Running_State: Slave 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:  
        Auto_Position: 0 
     Replicate_Rewrite_DB:  
         Channel_Name:  
      Master_TLS_Version:  
1 row in set (0.00 sec) 
 
ERROR:  
No query specified 
 
mysql>