1. 系统环境
cat /etc/redhat-release
CentOS Linux release 7.9.2009 (Core)
192.168.183.137 mysql-master
192.168.183.153 mysql-slave-1
192.168.183.154 mysql-slave-2
# 关闭SELINUX
sed -i 's/SELINUX=enforcing/SELINUX=disabled/g' /etc/selinux/config
setenforce 0
# 关闭防火墙
systemctl stop firewalld
systemctl disable firewalld2. 安装MySQL
三台机器均执行
wget https://dev.mysql.com/get/mysql80-community-release-el7-7.noarch.rpm
yum -y install mysql80-community-release-el7-7.noarch.rpm
yum clean all && yum makecache
yum -y install mysql-community-server
systemctl start mysqld
systemctl enable mysqld
# 查看root密码
grep 'temporary password' /var/log/mysqld.log
mysql -uroot -ppassword
# 修改root密码
ALTER USER 'root'@'localhost' IDENTIFIED BY 'password';
FLUSH PRIVILEGES;3. mysql-master配置文件修改
vim /etc/my.cnf
# 加入以下内容
server_id=137 # server_id需要保证唯一性，不可与其他从服务器相同 如果为0会拒绝所有从服务器连接
log-bin=mysql-bin # 设置同步的binary log二进制日志文件名前缀，默认是binlog
binlog_ignore_db = information_schema # 不需要同步的数据库
binlog_ignore_db = performance_schema # 不需要同步的数据库
innodb_flush_log_at_trx_commit=1 # 我们每次事务的结束都会触发Log Thread 将log buffer中的数据写入文件并通知文件系统同步文件。这个设置是最安全的设置，能够保证不论是MySQL Crash 还是OS Crash或者是主机断电都不会丢失任何已经提交的数据。4. mysql-slave-1配置文件修改
vim /etc/my.cnf
# 加入以下内容
server_id=153
log-bin=mysql-bin
binlog_ignore_db = information_schema
binlog_ignore_db = performance_schema
innodb_flush_log_at_trx_commit=1 5. mysql-slave-2配置文件修改
vim /etc/my.cnf
# 加入以下内容
server_id=154
log-bin=mysql-bin
binlog_ignore_db = information_schema
binlog_ignore_db = performance_schema
innodb_flush_log_at_trx_commit=1 修改完成之后全部重启systemctl restart mysqld
6. 主库创建复制用户
mysql -uroot -ppassworn
# 创建同步账户master节点 执行
mysql> CREATE USER slave@'%' IDENTIFIED BY 'QAZqaz1234@';
mysql> GRANT ALL PRIVILEGES ON *.* TO 'slave'@'%'WITH GRANT OPTION;
mysql> CHANGE MASTER TO GET_MASTER_PUBLIC_KEY=1;
mysql> FLUSH PRIVILEGES;
mysql> SHOW MASTER STATUS;
mysql> show master status;
+------------------+----------+--------------+---------------------------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+---------------------------------------+-------------------+
| mysql-bin.000001 | 873 | | information_schema,performance_schema | |
+------------------+----------+--------------+---------------------------------------+-------------------+7. 配置从库
mysql -uroot -ppassworn
# slave-1和slave-2都是同样的操作
mysql> change master to
master_host='192.168.183.137',master_user='slave',master_password='QAZqaz1234@',
master_log_file='master-bin.000001',master_log_pos=873;
# 启动同步
mysql> START SLAVE;
mysql> FLUSH PRIVILEGES;mysql> SHOW SLAVE STATUS\G
Slave_IO_Running: Connecting，
报错：Error connecting to source 'slave@192.168.183.137:3306'. This was attempt 5/86400, with a delay of 60 seconds between attempts. Message: Authentication plugin 'caching_sha2_password' reported error: Authentication requires secure connection.
发生这个问题的原因是在 mysql 8.0 以后，caching_sha2_password是默认的身份验证插件，而不是以往的mysql_native_password。在 MySQL Command Line 工具下修改 mysql 的默认身份验证插件即可。
登录主库
ALTER USER slave@'%' IDENTIFIED WITH mysql_native_password BY 'QAZqaz1234@';
FLUSH PRIVILEGES;然后从库重新同步
# slave-1和slave-2都是同样的操作
mysql> STOP SLAVE;
mysql> change master to
master_host='192.168.183.137',master_user='slave',master_password='QAZqaz1234@',
master_log_file='master-bin.000001',master_log_pos=1323;
# 启动同步
mysql> RESET SLAVE;
mysql> START SLAVE;
mysql> FLUSH PRIVILEGES;再次查看同步状况可以看到已经成功：
mysql> SHOW SLAVE STATUS\G
8. 测试
在master节点上执行SQL语句
create database db_test;
show databases;
在从库上面查看
在master的db_test库里面创建表
use db_test;
# 创建一个my_user表：
CREATE TABLE `my_user` (
`id` tinyint(4) NOT NULL AUTO_INCREMENT,
`account` varchar(255) DEFAULT NULL,
`passwd` varchar(255) DEFAULT NULL,
PRIMARY KEY (`id`)
);
# 插入数据：
INSERT INTO `my_user` VALUES ('1', 'admin', 'admin');
INSERT INTO `my_user` VALUES ('2', 'pu', '12345');
INSERT INTO `my_user` VALUES ('3', 'system', 'system');
# 查看插入数据
select * from db_test.my_user;
到从库上都能查到则说明没问题。
