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 22481 1694 5 17:23 ? 00:00:03 /usr/bin/python /usr/share/PackageKit/helpers/yum/yumBackend.py get-updates none root 22591 22507 1 17:24 pts/0 00:00:00 grep --color=auto yum [root@bug ~]# kill -9 22481
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。
