Mysql8 cluster operation practice under CentOS7 (two)-master-slave replication

Introduction to the principle of master-slave replication:

• After the master server data is submitted, the data will be written to the Binary log
• The Slave server monitors the Binary log log through the IO thread. If the log changes, it will read and write the content to the relay log (relay log).
• The Relay thread monitors the relay log, and if the log changes, the incremental write operation of the log will be executed once and written to the data file.

Hardware planning (virtual machine)

CPU name	The S	IP	use	Remarks
Cent OS 7_107	Cent OS7	192.168.1.107	M aster/ write	Mysql8
Cent OS 7_108	Cent OS7	192.168.1.108	Slave/read	Mysql8
Cent OS 7_109	Cent OS7	192.168.1.109	Slave/read	Mysql8

Create three virtual machines, one master and two slaves.

The specific implementation steps of master-slave replication:

1. Master master server configuration

• Modify my.cnf

             

vi /etc/my.cnf

               #Enable binary files

               log-bin=mysql-bin

              #Set the unique ID of the server, which is used to distinguish the master from the server.

              server-id=107

• Restart the Mysql service

systemctl restart mysqld

• Log in to Mysql to authorize the Slave server

mysql -uroot -p

Enter the mysql password and press Enter to enter the mysql interface

• Create an account in the Master library with Replication Slave permissions and provide the Slave library with access to binary logs.

CREATE USER 'sluser'@'%' IDENTIFIED BY '123456';

GRANT REPLICATION SLAVE ON *.* TO 'sluser'@'%';

• Refresh permissions

flush privileges;

• View Master status

show master status;

         2.S Lave from the server configuration

Servers 108 and 109 are slave servers. The following only demonstrates the configuration of the slave servers of 108. The configuration methods of 109 and 108 are the same, so we will not repeat them here.

• Modify my.cnf

vi /etc/my.cnf

Add the following content

server-id=108

replay-log=mysql-bin

• Log in to mysql and configure the slave server

Set up the slave server to monitor the master server

CHANGE MASTER TO  MASTER_HOST='192.168.1.107',MASTER_USER='sluser',MASTER_PASSWORD='123456',MASTER_LOG_FILE='mysql-bin.000001', MASTER_LOG_POS=1707;

Description:

MASTER_HOST: master ip or virtual ip or domain name

MASTER_USER: The login account name previously created on the master

MASTER_PASSWORD: the password of the created login account

MASTER_LOG_FILE：master的file

MASTER_LOG_POS：master的position

• Start copy function from server

start slave;

• View the status of the slave server

show slave status \G

If Slave_IO_Running: Yes

Slave_SQL_Running: Yes, indicating that our slave server is successfully configured, and the master-slave replication configuration has been completed.

         3. Test the master-slave replication function

• The main server creates a database and adds the t_user table

create database testdb;

use testdb；

DROP TABLE IF EXISTS `t_user`;

CREATE TABLE `t_user`  (

  `id` int(11) NOT NULL AUTO_INCREMENT,

  `name` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL,

  `age` int(11) NOT NULL,

  PRIMARY KEY (`id`) USING BTREE

) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;

INSERT INTO `t_user` VALUES (1, 'test', 25);

• View the database from the server

show databases;

use testdb；

show tables;

select * from t_user;

You can see that the tables created on the master server and the data written can also be queried in the slave server, indicating that our master-slave replication configuration is successful.