MySQL主从不同步、数据不一致解决办法

第一种:通过sql_slave_skip_counter跳过同步错误，适用于一般异常如插入时主键冲突

这种情况一般是在从库进行了写操作，错误提示

Last_SQL_Errno: 1062

Last_SQL_Error: Error 'Duplicate entry '14' for key 'PRIMARY'' on query. Default database: 'hadoop'. Query: 'INSERT INTO `user` (`username`, `password`) VALUES ('b', 'b')'
1 row in set (0.00 sec)

如果提示

Last_SQL_Errno: 126
Last_SQL_Error: Error 'Incorrect key file for table './hadoop/user.MYI'; try to repair it' on query. Default database: 'hadoop'. Query: 'INSERT INTO `user` (`username`, `password`) VALUES ('c', 'c')'

则先修复下表repair table user;再继续下面的操作

从库执行:

1.  
   #停止slave服务
2.  
   mysql> stop slave;
3.  
   Query OK, 0 rows affected, 1 warning (0.00 sec)
4.  
   #跳过一步错误，后面的数字可变，如果还不行可执行多次
5.  
   mysql> set global sql_slave_skip_counter =1;
6.  
   Query OK, 0 rows affected (0.00 sec)
7.  
   #开始slave服务
8.  
   mysql> start slave;
9.  
   Query OK, 0 rows affected (0.00 sec)
10.  
    #查看slave状态
11.  
    mysql> show slave statusG
12.  
    *************************** 1. row ***************************
13.  
    Slave_IO_State: Waiting for master to send event
14.  
    Master_Host: 192.168.20.195
15.  
    Master_User: test
16.  
    Master_Port: 3306
17.  
    Connect_Retry: 60
18.  
    Master_Log_File: mysql-bin.000004
19.  
    Read_Master_Log_Pos: 251
20.  
    Relay_Log_File: mysqld-relay-bin.000006
21.  
    Relay_Log_Pos: 251
22.  
    Relay_Master_Log_File: mysql-bin.000004
23.  
    Slave_IO_Running: Yes
24.  
    Slave_SQL_Running: Yes
25.  
    Replicate_Do_DB:
26.  
    Replicate_Ignore_DB:
27.  
    Replicate_Do_Table:
28.  
    Replicate_Ignore_Table:
29.  
    Replicate_Wild_Do_Table:
30.  
    Replicate_Wild_Ignore_Table: mysql.%,information_schema.%,performance_schema.%
31.  
    Last_Errno: 0
32.  
    Last_Error:
33.  
    Skip_Counter: 1
34.  
    Exec_Master_Log_Pos: 251
35.  
    Relay_Log_Space: 552
36.  
    Until_Condition: None
37.  
    Until_Log_File:
38.  
    Until_Log_Pos: 0
39.  
    Master_SSL_Allowed: No
40.  
    Master_SSL_CA_File:
41.  
    Master_SSL_CA_Path:
42.  
    Master_SSL_Cert:
43.  
    Master_SSL_Cipher:
44.  
    Master_SSL_Key:
45.  
    Seconds_Behind_Master: 0
46.  
    Master_SSL_Verify_Server_Cert: No
47.  
    Last_IO_Errno: 0
48.  
    Last_IO_Error:
49.  
    Last_SQL_Errno: 0
50.  
    Last_SQL_Error:
51.  
    1 row in set (0.00 sec)

第二种:重新做主从，然后使用change master指定同步位置，这种耗时长
主库执行：

1.  
   mysql> flush tables with read lock;
2.  
   [root@hd3 ~]# mysqldump -uroot -p123456 --lock-all-tables --flush-logs hadoop > /data/hadoop.sql
3.  
   [root@hd3 ~]# scp /data/hadoop.sql root@192.168.20.201:/data/
4.  
   mysql> unlock tables;

从库执行:

1.  
   mysql> stop slave;
2.  
   Query OK, 0 rows affected (0.00 sec)
3.  
   mysql> reset slave;
4.  
   Query OK, 0 rows affected (0.01 sec)
5.  
   mysql> source /data/hadoop.sql
6.  
   mysql> change master to master_host='192.168.20.195', master_port=3306, master_user='test',master_password='123456', master_log_file='mysql-bin.000003',master_log_pos=932;
7.  
   Query OK, 0 rows affected (0.03 sec)
8.  
   mysql> start slave;
9.  
   Query OK, 0 rows affected (0.00 sec)

第三种：使用第三方工具如pt-table-sync