Resolve MySQL Master never sync issues

Resolve MySQL Master never sync

Today, MySQL's master and slave databases are not synchronized.

First on the Master library:

Mysql>show processlist; See if the next process is too much sleep. Found to be normal.

Show master status; also normal.

Mysql> Show master status;

+-------------------+----------+--------------+-------------------------------+

| File | Position | binlog_do_db | binlog_ignore_db |

+-------------------+----------+--------------+-------------------------------+

|     mysqld-bin.000001 |              3260 | | Mysql,test,information_schema |

+-------------------+----------+--------------+-------------------------------+

1 row in Set (0.00 sec)

Go to the slave and check it out.

Mysql> Show Slave Status\g

Slave_io_running:yes

Slave_sql_running:no

Visible is slave different steps

Two workarounds are described below:

Method one: After ignoring the error, continue syncing

This method is applicable to the case that the data of master-slave database is not very different, or the data can not be completely unified, the data requirements are not strict.

Solve:

Stop slave;

#表示跳过一步错误, the following numbers are variable

Set global sql_slave_skip_counter = 1;

Start slave;

Then use mysql> Show slave status\g to view:

Slave_io_running:yes

Slave_sql_running:yes

OK, now the master-slave synchronization state is normal ...

Mode two: Re-master from, fully synchronized

This method is suitable for the case that the master-slave database data is large or the data is completely unified.

The steps to resolve are as follows:

1. Advanced Master Library, lock table, prevent data write

Use the command:

Mysql> flush tables with read lock;

Note: This is locked to a read-only state, and the statement is case insensitive

2. Perform data backup

#把数据备份到mysql. bak.sql file

[[email protected] MySQL] #mysqldump-uroot-p-hlocalhost > Mysql.bak.sql

Note here: Database backups must be done on a regular basis, with shell scripts or Python scripts, to make sure the data is foolproof

3. View Master Status

Mysql> Show master status;

+-------------------+----------+--------------+-------------------------------+

| File | Position | binlog_do_db | binlog_ignore_db |

+-------------------+----------+--------------+-------------------------------+

|     mysqld-bin.000001 |              3260 | | Mysql,test,information_schema |

+-------------------+----------+--------------+-------------------------------+

1 row in Set (0.00 sec)

4. Upload the MySQL backup file to the slave library for data recovery

#使用scp命令

[Email protected] mysql]# SCP mysql.bak.sql [email protected]:/tmp/

5. Stop the state from the library

mysql> stop Slave;

6. Then run the MySQL command from the library, import the data backup

Mysql> Source/tmp/mysql.bak.sql

7. Set synchronization from the library, note that the synchronization point is in the main library show Master status information | file| Position two items

Change Master to Master_host = ' 192.168.128.100 ', master_user = ' rsync ', master_port=3306, master_password= ', Master_log _file = ' mysqld-bin.000001 ', master_log_pos=3260;

8. Re-open from sync

mysql> start slave;

9. View sync Status

Mysql> Show slave status\g View:

Slave_io_running:yes

Slave_sql_running:yes

Resolve MySQL Master never sync issues