MySQL Last_SQL_Errno: 1062----经典错误，主键冲突

一、基础信息

1. Centos7.4

2.MySQL 5.7.21

3.基于gtid的复制

二、异常描述

误把从节点当成主节点插入一条数据，同一条数据在主、从节点插入都进行了一次插入操作，导致主键冲突，slave下的SQL线程异常。

建议设置从库为只读：

set global read_only=1;--针对普通MySQL数据库用户设置为只读
set global super_read_only=1;--针对super类MySQL数据库用户设置为只读，比如root用户

my.cnf 文件设置永久只读

read_only=1
super_read_only=1;

三、处理过程  

1.查看报错信息-- 报错大致如下

mysql> show slave status G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.1.1
                  Master_User: repuser
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql_binlog.000023
          Read_Master_Log_Pos: 2266930
               Relay_Log_File: devmidsrv01kf-relay-bin.000003
                Relay_Log_Pos: 423
        Relay_Master_Log_File: mysql_binlog.000016
             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: 1062
                   Last_Error: Could not execute Write_rows event on table testdb1.students; Duplicate entry '8' for key 'PRIMARY', Error_code: 1062; handler error HA_ERR_FOUND_DUPP_KEY; the event's master log mysql_binlog.000016, end_log_pos 340380520
                 Skip_Counter: 0
          Exec_Master_Log_Pos: 340380190
              Relay_Log_Space: 6541566399
              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: 1062
               Last_SQL_Error: Could not execute Write_rows event on table testdb1.students; Duplicate entry '8' for key 'PRIMARY', Error_code: 1062; handler error HA_ERR_FOUND_DUPP_KEY; the event's master log mysql_binlog.000016, end_log_pos 340380520
  Replicate_Ignore_Server_Ids: 
             Master_Server_Id: 757
                  Master_UUID: 7bd36140-a92d-11e9-ba1f-005056a4099b
             Master_Info_File: /data/mysql/3306/data/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: 191205 16:19:02
               Master_SSL_Crl: 
           Master_SSL_Crlpath: 
           Retrieved_Gtid_Set: 7bd36140-a92d-11e9-ba1f-005056a4099b:835084-2324874
            Executed_Gtid_Set: 7bd36140-a92d-11e9-ba1f-005056a4099b:1-835083,
bcad977d-a934-11e9-a589-005056a483f4:1-29
                Auto_Position: 1
         Replicate_Rewrite_DB: 
                 Channel_Name: 
           Master_TLS_Version: 
1 row in set (0.00 sec)

2.确认需要跳过的gtid是关键

找到这个已经执行的gtid，加1

7bd36140-a92d-11e9-ba1f-005056a4099b:1-835083

3.跳过gtid

stop slave;

SET @@SESSION.GTID_NEXT= '7bd36140-a92d-11e9-ba1f-005056a4099b:1-835084';

BEGIN; COMMIT;

SET SESSION GTID_NEXT = AUTOMATIC;

START SLAVE;

4、检查

mysql> show slave status G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.1.1
                  Master_User: repuser
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql_binlog.000023
          Read_Master_Log_Pos: 2266930
               Relay_Log_File: devmidsrv01kf-relay-bin.000003
                Relay_Log_Pos: 423
        Relay_Master_Log_File: mysql_binlog.000016
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes