Mysql master-slave synchronization reset

background

The server was forced to restart, resulting in data inconsistency between the master and slave databases of MySQL. The data difference between the master and slave databases was large, and the data synchronization could not be completed, and an error was reported. Therefore, a master-slave synchronous reset operation is required.

1. First operate the slave library

• 1) Enter the MySQL command line management interface

mysql -uroot -p

• 2) stop slave

stop slave;

• 3) Reset the slave library

reset slave all;

• 4) Clear the synchronized database

drop database `***`;

2. Operate the main library

• 1) Reset the synchronization settings of the main library

RESET MASTER;

• 2) Lock the main library, only read

FLUSH TABLES WITH READ LOCK;

• 3) Export mysql data

mysqldump –h(ip***) –P(port***) –u(user***) –p(pwd***) --all-databases > /master-dump.sql

4) Unlock the main library

UNLOCK TABLES;

3. Import the data exported from the main library from the library

• 1) Import data

mysql -r root -p 数据库名 < d:\user\userxxx.sql 

• 2) Modify the synchronization settings from the library

change master to master_host='主库ip（192.168.1.1）',master_user='root',master_password='123456',master_log_file='mysql-bin.000001',master_log_pos=154;
# master_log_file 如下图获取
# master_log_pos 如下图获取

• 3) Obtain master_log_file and master_log_pos data
  Enter the main database MySQL management interface, execute a command to view master_log_file and master_log_pos data

show master status;

• 4) Turn on the slave library

start slave;

• 5) View slave status

show slave status\G;

As shown in the figure below, the configuration is successful.

appendix

1. Set the master-slave configuration:
   
2. Add data synchronization account:

grant replication slave on *.* to 'root'@'%' identified by '123456';

3. restart mysql

mysql restart