[highly available MySQL solution] centos7 configures MySQL master-slave replication

Common high availability MySQL The solution includes master-slave replication , Master master copy ,Heartbeat/SAN High availability ,MySQL Cluster High availability, etc . Here I use the simplest master-slave replication high availability scheme , It's also Mysql Built in features .

mysql Master slave replication principle ：

1. master Record data changes to a binary log (binary log) in , That is, the configuration file log-bin Specified file ( These records are called binary log events )
2. slave take master Of binary log events Copy to its trunk log (relay log)
3. slave Redo events in relay log , Will change the data that reflects itself ( Data replay )

In fact, it is synchronized according to the log file of the main database .

Support type

1. Statement based replication : Executed on the primary server SQL sentence , Execute the same statement on the slave server .MySQL Statement based replication is used by default , High efficiency
2. Line based replication : Copy the changed content directly , It doesn't matter which statement caused the change . from mysql5.0 Start supporting
3. Hybrid type of replication : Statement based replication is used by default , Once it is found that statement based replication cannot be accurate , You'll use row based replication .

precondition

1. Lord DB server And from the DB server The database version is consistent
2. Lord DB server And from the DB server Database data is consistent [ You can restore the primary backup on the secondary ]
3. Lord DB server Turn on binary log , Lord DB server And from the DB server Of server_id Must be unique

The detailed steps

master server node200：192.168.212.200

From the server node201：192.168.212.201（ You can set up multiple slave servers ）

1. Two machines selinux All are disable

2. Modify the master DB server Configuration file for (/etc/my.cnf), Turn on the log function , Set up server_id value , Ensure that the only [node200 Mainly DB server]

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[[email protected] ~]# vi /etc/my.cnf # Modify the configuration file , The following two parameters ： # Set up server_id, It is generally recommended to set IP, Or add some numbers server_id = 200 # Turn on binary log function , You can take it , Better have meaning log-bin=mysql3306-bin

3. Start the database server , And log in to the database , Grant corresponding users for synchronization

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mysql -uroot -p mysql> GRANT REPLICATION SLAVE,RELOAD,SUPER ON *.* TO 'slave1'@'192.168.212.201' IDENTIFIED BY 'winstore'; # Refresh authorization table information mysql> FLUSH PRIVILEGES; # Check and write down position Number and log file name ( Very important ) mysql> show master status; +----------------------+----------+--------------+------------------+-------------------+ | File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set | +----------------------+----------+--------------+------------------+-------------------+ | mysql3306-bin.000002 | 399 | | | | +----------------------+----------+--------------+------------------+-------------------+ 1 row in set (0.00 sec)

4. To ensure the Lord DB server And from the DB server The data are consistent , Here, the primary backup is used , From restore to achieve initial data consistency

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# Lord DB Log on to # Temporary lock table mysql> flush tables with read lock; # I implement full database backup here , In practice, , We might just synchronize one library , You can back up only one library # Open a new terminal , Do the following [[email protected] ~]# mysqldump -uroot -p --all-databases > /tmp/mysql.sql # Unlock mysql> unlock tables; # Transfer the backup data to the slave , Used to recover [[email protected] ~]# scp /tmp/mysql.sql [email protected]:/tmp

5. Only one item needs to be modified from the database configuration file , Use the command line to do the rest

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[[email protected] ~]# vi /etc/my.cnf # Set up server_id, It is generally recommended to set IP server_id = 201

6. Start from database , Restore backup data

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# Start database [[email protected] ~]# systemctl restart mysqld.service # Restore master DB server Backup data [[email protected] ~]# mysql -uroot -p < /tmp/mysql.sql

7. Log in from the database , Add relevant parameters ( Lord DBserver Of ip/ port / Synchronize users / password /position Number / Which log file to read )

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[[email protected] ~]# mysql -uroot -p mysql> change master to -> master_host='192.168.212.200', -> master_user='slave1', -> master_password='winstore', -> master_port=3306, -> master_log_file='mysql3306-bin.000002', -> master_log_pos=399; # Turn on master-slave synchronization mysql> start slave; # Check the master-slave synchronization status mysql> show slave status\G; # Look at the following two parameters ：[ If these two parameters are yes It means that the master-slave synchronization is normal ] Slave_IO_Running: Yes Slave_SQL_Running: Yes

8. Now you can be in the Lord DB server Create a new table , See if you can synchronize to from DB server On , I won't test it here

see server_id：

1	mysql> show variables like '%server_id%';