MySQL 8.0.18 InnoDB Cluster 主从（MGR）完整安装配置

提示： MySQL InnoDB Cluster底层依赖Group Replication模式，至少3台机器

1.  准备3台 CentOS Linux 7 (Core)， 修改各主机名：db-host1， db-host2， db-host3  然后配置各台机器 hosts 映射， 对应如下

cat << EOF >> /etc/hosts
192.168.50.181 db-host1
192.168.50.182 db-host2
192.168.50.183 db-host3
EOF

2. 确保3台服务器要互相访问正常，为了保险期间请关闭防火墙，firewalld常用命令 如：

# 启动
systemctl start firewalld

# 关闭
systemctl stop firewalld

# 查看状态
systemctl status firewalld 

# 开机禁用
systemctl disable firewalld

# 开机启用
systemctl enable firewalld

# 查看所有打开的端口
 firewall-cmd --zone=public --list-ports

3. 确保互访使用ssh 共享，这里使用root 账户 如：在db-host1 执行，其它以此类推：

ssh-keygen -t rsa
ssh-copy-id -i ~/.ssh/id_rsa.pub 192.168.50.182

ssh-keygen -t rsa
ssh-copy-id -i ~/.ssh/id_rsa.pub 192.168.50.183

4. 准备安装 mysql-community-server，mysql-shell，mysql-router 在3台机器安装，注意版本：

wget https://dev.mysql.com/get/mysql80-community-release-el7-3.noarch.rpm
rpm -ivh mysql80-community-release-el7-3.noarch.rpm
yum install mysql-community-server

wget https://dev.mysql.com/get/Downloads/MySQL-Shell/mysql-shell-8.0.18-1.el7.x86_64.rpm
rpm -ivh mysql-shell-8.0.18-1.el7.x86_64.rpm
yum install mysql-shell

wget https://dev.mysql.com/get/Downloads/MySQL-Router/mysql-router-community-8.0.18-1.el7.x86_64.rpm
rpm -ivh mysql-router-community-8.0.17-1.el7.x86_64.rpm
yum install mysql-router

5. 安装完MysqlServer 后，依次每台初始化mysql,步骤如下：#初始化：

mysqld --initialize;

#赋访问权限：
chown mysql:mysql /var/lib/mysql -R

#启动mysql服务：
systemctl start mysqld.service;

#设置mysql开机自启
mysql systemctl enable mysqld;

#命令查看数据库的密码：
cat /var/log/mysqld.log | grep password

#进入mysql命令行：
mysql -uroot -p (输入上述查看的数据库密码进入mysql命令行)
#命令来修改密码： 
ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY  '密码';

#创建远程访问权限：
create user 'root'@'%' identified with mysql_native_password by  '密码';

GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' WITH GRANT OPTION;

flush privileges;

6. 由于依赖组复制，在host1 修改  /etc/my.cnf

server_id = 4000000161
loose-group_replication_group_name="a38e32fd-5fb6-11e8-ad7a-00259015d941"
loose-group_replication_local_address= "192.168.50.181:3306"
loose-group_replication_group_seeds= "192.168.50.181:3306,192.168.50.182:3306,192.168.50.183:3306"
loose-group_replication_single_primary_mode=TRUE

然后拷贝 /etc/my.cnf到另外2台机器

rsync -e "ssh -p22" -avpgolr /etc/my.cnf root@192.168.50.182:/etc/
rsync -e "ssh -p22" -avpgolr /etc/my.cnf root@192.168.50.183:/etc/

确保各自 server_id  和 address

host1    server_id = 4000000161

loose-group_replication_local_address= "192.168.50.181:3306"

host2    server_id = 4000000162

loose-group_replication_local_address= "192.168.50.182:3306"

host3    server_id = 4000000163

loose-group_replication_local_address= "192.168.50.183:3306"

7. 3台mysql server 启动组复制

start group_replication

8. 检查实例配置， 使用 mysqlsh

dba.checkInstanceConfiguration('root@db-host1:3306')
dba.checkInstanceConfiguration('root@db-host2:3306')
dba.checkInstanceConfiguration('root@db-host3:3306')

8. 配置实例

dba.configureInstance('root@db-host1:3306',{'restart': true})
dba.configureInstance('root@db-host2:3306',{'restart': true})
dba.configureInstance('root@db-host3:3306',{'restart': true})

9. 创建添加实例

var cluster = dba.createCluster('mycluster');
var cluster=dba.getCluster('mycluster')
cluster.addInstance('root@db-host2:3306');
cluster.addInstance('root@db-host3:3306');

10. 登录主服务器 ，查看，配置成功

mysql> select * from performance_schema.replication_group_members;

注意：由于8.0 中的一些变化和5.X配置有所配置不同，按照以前的配置容易出错，要善于对应分析日志进行排错

推荐参考资料：

https://blog.csdn.net/wzy0623/article/details/100779450

https://www.jianshu.com/p/6e2918845ec8

https://lefred.be/content/mysql-8-0-innodb-cluster-the-quick-hands-on-manual/

https://cloud.tencent.com/developer/article/1445710