MySQL8.0 MIC高可用集群搭建

mysql8.0带来的新特性，结合MySQLshell，不需要第三方中间件，自动构建高可用集群。

mysql8.0作为一款新产品，其内置的mysq-innodb-cluster（MIC）高可用集群的技术确实惊艳，结合MySQLshell能够实施集群的快速部署，MySQL-route能够实现灾备快速切换，内置读写分离技术，负载均衡技术。结合但实际效果如何，还需验证。

一，集群部署

1.1 安装环境；

操作系统：Linux，版本：CentOS-7-x86

介质准备：无

环境清理

释放yum进程

[root@bug ~]# ps -ef|grep yum
root          : ?        :: /usr/bin/python /usr/share/PackageKit/helpers/yum/yumBackend.py get-updates none
root         : pts/    :: grep --color=auto yum
[root@bug ~]# kill - 

查看是否有多余系统，有则卸载

[root@bug ~]# rpm -qa|grep mairadb
[root@bug ~]# rpm -qa|grep mysql

关闭防火墙

[root@bug ~]# systemctl status firewalld.service
● firewalld.service - firewalld - dynamic firewall daemon
   Loaded: loaded (/usr/lib/systemd/system/firewalld.service; enabled; vendor preset: enabled)
   Active: inactive (dead) 

关闭selinux，重启系统后生效

[root@bug selinux]# vi /etc/selinux/config
SELINUX=disabled
[root@bug selinux]# reboot

1.2 安装MySQL8.0

[root@bug ~]# yum install -y wget https://repo.mysql.com//mysql80-community-release-el7-1.noarch.rpm
[root@bug ~]# yum list|grep mysql
[root@bug ~]# yum install -y mysql-community-client.x86_64 mysql-router.x86_64 mysql-shell.x86_64

　采用YUM源安装方式，总下载量约400M，

1.3自动集群部署

部署节点1

[root@bug ~]# mysqlsh

 MySQL  JS >  dba.deploySandboxInstance(3310);
A new MySQL sandbox instance will be created on this host in
/root/mysql-sandboxes/3310

Warning: Sandbox instances are only suitable for deploying and
running on your local machine for testing purposes and are not
accessible from external networks.

Please enter a MySQL root password for the new instance: ******
Deploying new MySQL instance...

Instance localhost:3310 successfully deployed and started.
Use shell.connect('root@localhost:3310'); to connect to the instance.

　　第一个节点部署完毕，端口设置为3310，登陆账号为root@localhost，密码 ******

使用本地认证的方式， 登陆数据库实例，进行验证。

[root@bug ~]# mysql -uroot -porange -S /root/mysql-sandboxes/3310/sandboxdata/mysqld.sock
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.

　　

同样的方法，部署节点2，节点3。

MySQL  JS >  dba.deploySandboxInstance(3320); 

MySQL  JS > dba.deploySandboxInstance(3330);

1.4创建集群

此实验采用简单的创建本地集群。

 MySQL  JS >  \connect root@localhost:3310
Creating a session to 'root@localhost:3310'

*****************************************************
 MySQL  localhost:3310 ssl  JS >  var cluster=dba.createCluster('test')
A new InnoDB cluster will be created on instance 'root@localhost:3310'.

*********************************************************

Cluster successfully created. Use Cluster.addInstance() to add MySQL instances.
At least 3 instances are needed for the cluster to be able to withstand up to
one server failure.

　集群系统已经创建成功，最后一行：At least 3 instances are needed for the cluster to be able to withstand up to one server failure.提示需要至少三个实例，才能保证灾备，所以接下来，将节点2，3添加进集群。

MySQL  localhost:3310 ssl  JS > cluster.addInstance( 'root@localhost:3320')

The instance 'root@localhost:3320' was successfully added to the cluster.

 MySQL  localhost:3310 ssl  JS > cluster.addInstance( 'root@localhost:3330') 

The instance 'root@localhost:3330' was successfully added to the cluster.

查看集群状态

MySQL  localhost:3310 ssl  JS > dba.getCluster().status()
{
    "clusterName": "test",
    "defaultReplicaSet": {
        "name": "default",
        "primary": "localhost:3310",
        "ssl": "REQUIRED",
        "status": "OK",
        "statusText": "Cluster is ONLINE and can tolerate up to ONE failure.",
        "topology": {
            "localhost:3310": {
                "address": "localhost:3310",
                "mode": "R/W",
                "readReplicas": {},
                "role": "HA",
                "status": "ONLINE"
            },
            "localhost:3320": {
                "address": "localhost:3320",
                "mode": "R/O",
                "readReplicas": {},
                "role": "HA",
                "status": "ONLINE"
            },
            "localhost:3330": {
                "address": "localhost:3330",
                "mode": "R/O",
                "readReplicas": {},
                "role": "HA",
                "status": "ONLINE"
            }
        }
    },
    "groupInformationSourceMember": "mysql://root@localhost:3310"
}

　　

一个简单的包含三个节点的集群已经创建完成。可以完成数据同步，读写分离等功能，比如此刻3310端口的状态是"R/W"，同时read与write，3320与3330的状态是"R/O"，只读模式。

1.5配置中间件

此时的集群的高可用性还不完整，需要MySQL-router来完成集群与外部的对接，实现自动切换，故障转移等功能。

MySQL-router的作用类似keepalived 类的中间件。当主机发生故障后，自动将应用切换到其他实例。

[root@bug ~]#  mysqlrouter --bootstrap root@localhost:3310 --user=mysqlrouter
Please enter MySQL password for root: *****

Bootstrapping system MySQL Router instance...
Checking for old Router accounts
Creating account mysql_router2_j05xzi45m81x@'%'
MySQL Router  has now been configured for the InnoDB cluster 'test'.

The following connection information can be used to connect to the cluster.

Classic MySQL protocol connections to cluster 'test':
- Read/Write Connections: localhost:6446
- Read/Only Connections: localhost:6447
X protocol connections to cluster 'test':
- Read/Write Connections: localhost:64460
- Read/Only Connections: localhost:64470

Existing configurations backed up to '/etc/mysqlrouter/mysqlrouter.conf.bak'
[root@bug ~]# mysqlrouter&
[1] 25602
[root@bug ~]#  ps -ef|grep router
mysqlro+ 25602 22507  8 19:35 pts/0    00:00:01 mysqlrouter
root     25619 22507  0 19:36 pts/0    00:00:00 grep --color=auto router

　　

验证MySQL-router安装效果

在MySQL-router默认配置下，

主机端口：6446

从库端口：6447

[root@bug ~]#  mysql -uroot -h 127.0.0.1 -P 6446 -p
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
********************************************************8
mysql>

　证明MySQL-router配置完成可用。

1.6验证集群效果

1,通过router同时登陆三个节点，查看端口号。

2,在节点1构造数据，在节点2，3差看状态，验证数据同步性。

3,节点1（主机）离线，查看集群状态与节点2，节点3状态，验证灾备能力。