(13) MySQL master-slave replication

(1) Working principle

(2) Master-slave implementation

1) Environment introduction

/etc/redhat-release 
CentOS Linux release 7.3.1611 (Core)

MySQL version: 5.7

mysql> select version();
+------------+
| version()  |
+------------+
| 5.7.22-log |
+------------+

2) master side configuration

• Prepare data

  mysql>  mysql -uroot -pRedhat@123 -e 'create database testdb;
  mysql>  create table testdb.t1(id int,name varchar(50));
  mysql>  insert into testdb.t1 values(1,'jack');
  mysql>  insert into testdb.t1 values(2,'alex');

• Enable binary logging and configure server-id

  #vim /etc/my.cnf
  log-bin
  server-id=1

• restart the server

  #systemctl restart mysqld

• Create an authorized account

  mysql> grant replication slave,replication client on *.* to 'rep'@'192.168.111.%' identified by 'Reprep@123';
  mysql> flush privileges;

• backup database

  mysqldump -uroot -pRedhat@123 -A -R  --single-transaction --master-data=1 --flush-logs >$(date +%F)-mysql-all.sql

• Copy the backup database file to the slave host

  scp -r 2018-04-26-mysql-all.sql [email protected]:/root

• After creating some data after full backup

  mysql> insert into testdb.t1 values(3,'www');
  mysql> insert into testdb.t1 values(4,'yyyy');

  3) Slave side configuration

• Verify whether the account created by the main library can log in normally, and also verify whether there is a firewall problem

  # mysql -h192.168.111.151 -urep -p'Reprep@123'

• Configure the server-id of the slave library and set the slave library to be read-only.
  Pay attention to the permission of the application to connect to the slave library. Do not give all permissions, only make the slave library read-only.

  #vim /etc/my.cnf
  server-id=2
  read-only 

• restart the database

  #systemctl restart mysqld

• Import the backup to the slave library: It is strongly recommended to use the source method to import sql backup to the slave library. It is
  not recommended to use mysql -uroot -pRedhat@123 </root/2018-04-26-mysql-all.sql, otherwise the change master needs to Specify pos file and location point

  mysql>source /root/2018-04-26-mysql-all.sql   

• Link to the main library

  mysql> change master to 
  -> master_host='192.168.111.151',               \\生成环境建议使用主机名，不建议使用ip地址
  -> master_user='rep',
  -> master_password='Reprep@123';

• Enable replication and verification status

  mysql> start slave;
  mysql> show slave status\G
    Slave_IO_Running: Yes
          Slave_SQL_Running: Yes

• verify the data

  mysql> select * from testdb.t1;
  +------+------+
  | id   | name |
  +------+------+
  |    1 | jack |
  |    2 | alex |
  |    3 | www  |
  |    4 | yyyy |
  +------+------+