MySQL主从同步状态

因为mysql的slave报错，导致slave落后master很远。找资料查看同步状态。

引用

mysql> show slave status\G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.0.103
                  Master_User: root
                  Master_Port: 3306
                Connect_Retry: 10
              Master_Log_File: masterlog.000298
          Read_Master_Log_Pos: 780437928
               Relay_Log_File: db-relay-bin.000246
                Relay_Log_Pos: 589923335
        Relay_Master_Log_File: masterlog.000298
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
              Replicate_Do_DB: byread
          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: 780437928
              Relay_Log_Space: 793806494
              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:
1 row in set (0.00 sec)

如果下面一个为NO，表明同步停止。

引用

If either of these is NO, like this, then replication is stopped:
Slave_IO_Running: No
Slave_SQL_Running: No

以下两项会告诉你什么出错。

引用

The Last_Errno and Last_Error might give you a clue as to what went wrong.

[url]
http://homepage.mac.com/kelleherk/iblog/C711669388/E20070717105144/index.html
[/url]

同步主库文件和位置

引用

Master_Log_File: masterlog.000298
Read_Master_Log_Pos: 780437928

从库执行到的文件位置

引用

Relay_Master_Log_File: masterlog.000298
Exec_Master_Log_Pos: 780437928

当主库和从库对应一致时表明同步正常。