MySQL主从复制不能同步，查看slave状态，报错如下：

mysql> show slave status \G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.0.134
                  Master_User: slave
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: master-bin.000006
          Read_Master_Log_Pos: 520
               Relay_Log_File: relay-log-bin.000028
                Relay_Log_Pos: 252
        Relay_Master_Log_File: master-bin.000006
             Slave_IO_Running: Yes
            Slave_SQL_Running: No
              Replicate_Do_DB: 
          Replicate_Ignore_DB: 
           Replicate_Do_Table: 
       Replicate_Ignore_Table: 
      Replicate_Wild_Do_Table: 
  Replicate_Wild_Ignore_Table: 
                   Last_Errno: 1008
                   Last_Error: Error 'Can't drop database 'aaa'; database doesn't exist' on query. Default database: ''. Query: 'drop database aaa'
                 Skip_Counter: 1
          Exec_Master_Log_Pos: 356
              Relay_Log_Space: 868
              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: NULL
Master_SSL_Verify_Server_Cert: No
                Last_IO_Errno: 0
                Last_IO_Error: 
               Last_SQL_Errno: 1008
               Last_SQL_Error: Error 'Can't drop database 'aaa'; database doesn't exist' on query. Default database: ''. Query: 'drop database aaa'
1 row in set (0.00 sec)

解决办法：

mysql> stop slave; 
Query OK, 0 rows affected (0.00 sec)
mysql> set global sql_slave_skip_counter = 1; # 将同步指针向下移动一个，可以重复操作
mysql> start slave;
Query OK, 0 rows affected (0.00 sec)
mysql> show slave status \G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.0.134
                  Master_User: slave
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: master-bin.000006
          Read_Master_Log_Pos: 520
               Relay_Log_File: relay-log-bin.000030
                Relay_Log_Pos: 252
        Relay_Master_Log_File: master-bin.000006
             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: 520
              Relay_Log_Space: 551
              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)