基于GTID Replication主从数据不一致操作

基本的M-S结构

 

现在master与slave主机数据一致：

 

mysql> select * from t1;
+------+
| id   |
+------+
|    1 |
|    2 |
|    4 |
+------+
3 rows in set (0.00 sec)

 

我们来模拟故障现象：

在master上，通过设置sql_log_bin来控制命令是否写入二进制日志中，运行命令：

set sql_log_bin=OFF;
insert into t1 values(5);
set sql_log_bin=ON;
insert into t1 values(6);

这样数据在master上是这样的：

mysql> select * from t1;
+------+
| id   |
+------+
|    1 |
|    2 |
|    4 |
|    5 |
|    6 |
+------+
5 rows in set (0.00 sec)

而在slave上的数据是这样的：

mysql> select * from testdb.t1;
+------+
| id   |
+------+
|    1 |
|    2 |
|    4 |
|    6 |
+------+
4 rows in set (0.00 sec)

此时我们在master上执行操作：

update t1 set id=7 where id=5;
insert into t1 values(8);

mysql> select * from t1;
+------+
| id   |
+------+
|    1 |
|    2 |
|    4 |
|    7 |
|    6 |
|    8 |
+------+
6 rows in set (0.00 sec)

我们查询一下slave上的数据：

mysql> select * from testdb.t1;
+------+
| id   |
+------+
|    1 |
|    2 |
|    4 |
|    6 |
+------+
4 rows in set (0.00 sec)

发现数据并没有被同步过来，我们来show一下slave

mysql> show slave status\G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.203.135
                  Master_User: replmonitor
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: host2-bin.000002
          Read_Master_Log_Pos: 1146
               Relay_Log_File: host3-relay-bin.000003
                Relay_Log_Pos: 648
        Relay_Master_Log_File: host2-bin.000002
             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: 1032
                   Last_Error: Could not execute Update_rows event on table testdb.t1; Can't find record in 't1', Error_code: 1032; handler error HA_ERR_END_OF_FILE; the event's master log host2-bin.000002, end_log_pos 875
                 Skip_Counter: 0
          Exec_Master_Log_Pos: 660
              Relay_Log_Space: 1595
              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: 1032
               Last_SQL_Error: Could not execute Update_rows event on table testdb.t1; Can't find record in 't1', Error_code: 1032; handler error HA_ERR_END_OF_FILE; the event's master log host2-bin.000002, end_log_pos 875
  Replicate_Ignore_Server_Ids:
             Master_Server_Id: 2
                  Master_UUID: cd32a980-2a97-11e5-a344-000c2954ccde
             Master_Info_File: mysql.slave_master_info
                    SQL_Delay: 0
          SQL_Remaining_Delay: NULL
      Slave_SQL_Running_State:
           Master_Retry_Count: 86400
                  Master_Bind:
      Last_IO_Error_Timestamp:
     Last_SQL_Error_Timestamp: 150717 23:51:51
               Master_SSL_Crl:
           Master_SSL_Crlpath:
           Retrieved_Gtid_Set: cd32a980-2a97-11e5-a344-000c2954ccde:1-3
            Executed_Gtid_Set: cd32a980-2a97-11e5-a344-000c2954ccde:1
                Auto_Position: 1
1 row in set (0.00 sec)

此时我们查看一下错误日志：

 

2015-07-17 23:51:51 30750 [ERROR] Slave SQL: Could not execute Update_rows event on table testdb.t1; Can't find record in 't1', Error_code: 1032; handler error HA_ERR_END_OF_FILE; the event's master log host2-bin.000002, end_log_pos 875, Error_code: 1032
2015-07-17 23:51:51 30750 [Warning] Slave: Can't find record in 't1' Error_code: 1032
2015-07-17 23:51:51 30750 [ERROR] Error running query, slave SQL thread aborted. Fix the problem, and restart the slave SQL thread with "SLAVE START". We stopped at log 'host2-bin.000002' position 660

 

提示我们在修改错误并重新启动slave，但关键在于如何修正错误，一般我们采用如下方法：

 

在从机slave上执行：

 

mysql> stop slave;
Query OK, 0 rows affected (0.02 sec)

mysql> set gtid_next='cd32a980-2a97-11e5-a344-000c2954ccde:2';
Query OK, 0 rows affected (0.00 sec)

mysql> begin;
Query OK, 0 rows affected (0.00 sec)

mysql> commit;
Query OK, 0 rows affected (0.00 sec)

mysql> set gtid_next='AUTOMATIC';
Query OK, 0 rows affected (0.00 sec)

mysql> start slave;
Query OK, 0 rows affected (0.01 sec)

即跳过有错误的GTID编号

mysql> show slave status\G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.203.135
                  Master_User: replmonitor
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: host2-bin.000002
          Read_Master_Log_Pos: 1146
               Relay_Log_File: host3-relay-bin.000005
                Relay_Log_Pos: 688
        Relay_Master_Log_File: host2-bin.000002
             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: 1146
              Relay_Log_Space: 1429
              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: cd32a980-2a97-11e5-a344-000c2954ccde
             Master_Info_File: mysql.slave_master_info
                    SQL_Delay: 0
          SQL_Remaining_Delay: NULL
      Slave_SQL_Running_State: Slave has read all relay log; waiting for the slave I/O thread to update it
           Master_Retry_Count: 86400
                  Master_Bind:
      Last_IO_Error_Timestamp:
     Last_SQL_Error_Timestamp:
               Master_SSL_Crl:
           Master_SSL_Crlpath:
           Retrieved_Gtid_Set: cd32a980-2a97-11e5-a344-000c2954ccde:1-3
            Executed_Gtid_Set: cd32a980-2a97-11e5-a344-000c2954ccde:1-3
                Auto_Position: 1
1 row in set (0.00 sec)

mysql> select * from testdb.t1;
+------+
| id   |
+------+
|    1 |
|    2 |
|    4 |
|    6 |
|    8 |
+------+
5 rows in set (0.00 sec)

可以发现事务已经全部同步了，但现在数据却是不一致的。

这种适合在数据要求不高的情况下使用，如果后续还有其它数据操作，造成主从数据差异过大，就得用从主库的一个完整备份过来，再从某点开始做replication。