mysql-mmm高可用群集
一、概述
MMM（Master-Master replication manager for MySQL）是一套支持双主故障切换和双主日常管理的脚本程序。 MMM 使用 Perl 语言开发，主要用来监控和管理 MySQL Master-Master（双主）复制，可以说是 MySQL 主主复制管理器
虽然叫做双主复制，但是业务上同一时刻只运行对一个主进行写入，另一台备选主上提供部分读服务，以加速在主主切换时刻备选主的预热，可以说 MMM 这套脚本程序一方面实现了故障切换的功能，另一方面其内部附加的工具脚本也可以实现多个 Slave 的 Read 负载均衡
MMM 提供了自动和手动两种方式移除一组服务器中复制延迟较高的服务器的虚拟 IP，同时它还可以备份数据，实现两节点之间的数据同步等。由于 MMM 无法完全的保证数据一致性，所以 MMM 适用于对数据的一致性要求不是很高，但是又想最大程度的保证业务可用性的场景
二、MySQL-MMM 优缺点
优点：高可用性，扩展性好，出现故障自动切换，对于主主同步，在同一时间只提供一台数据库写操作，保证数据的一致性
缺点：Monitor 节点是单点，可以结合 Keepalived 实现高可用，对主机的数量有需求，需要实现读写分离，对程序来说是个挑战
三、MySQL-MMM 内部工作架构
（一）、进程类型
mmm_mond：监控进程，负责所有的监控工作，决定和处理所有节点角色活动。此脚本需要在监控机上运行
mmm_agentd：运行在每个 MySQL 服务器上（Master 和 Slave）的代理进程，完成监控的探针工作和执行简单的远端服务设置
mmm_control：一个简单的脚本，提供管理 mmm_mond 进程的命令
（二）、工作架构
（三）、工作原理
mysql-mmm 的监管端会提供多个虚拟 IP（VIP），包括一个可写的 VIP，多个可读的 VIP
通过监管的管理，这些 IP 会绑定在可用的 MySQL 之上
当某一台 MySQL 宕机时，监管会将 VIP 迁移至其它 MySQL
四、案例
| 系统类型 | 名称 | server ID | IP | VIP | role（角色） |
| CentOS 7.4 | monitor(监听) | 无 |
192.168.2.8 | 无 | |
| CentOS 7.4 | master1(主1) | 1 | 192.168.2.9 | 192.168.2.100 | writer |
| CentOS 7.4 | master2(主1) | 2 | 192.168.2.10 | 192.168.2.100 | writer |
| CentOS 7.4 | slave1(从1) | 3 | 192.168.2.11 | 192.168.2.101 | reader |
| CentOS 7.4 | slave2(从2) | 4 | 192.168.2.12 | 192.168.2.102 | reader |
（一）、 准备工作
1、 在monitor、master1、master2、slave1、slave2配置域名解析
直接复制修改ip或名称
echo '
192.168.2.8 monitor
192.168.2.9 master1
192.168.2.10 master2
192.168.2.11 slave1
192.168.2.12 slave2'>> /etc/hosts2、 在master1上安装配置ntp服务
[root@master1 ~]# yum -y install ntp
.......
...
[root@master1 ~]# sed -i '/^server/s/^/#/g' /etc/ntp.conf
[root@master1 ~]# echo '
server 127.127.1.0
fudge 127.127.1.0 stratum 8
' >> /etc/ntp.conf
[root@master1 ~]# systemctl start ntpd
[root@master1 ~]# systemctl enable ntpd
Created symlink from /etc/systemd/system/multi-user.target.wants/ntpd.service to /usr/lib/systemd/system/ntpd.service.
3、 master2上配置ntp时间
[root@master2 ~]# yum -y install ntp
[root@master2 ~]# /usr/sbin/ntpdate 192.168.2.9
21 Dec 15:48:55 ntpdate[55094]: adjust time server 192.168.2.9 offset 0.000702 sec
[root@master2 ~]# echo "/usr/sbin/ntpdate 192.168.2.9" >> /etc/rc.local
[root@master2 ~]# chmod +x /etc/rc.local monitor、slave1、slave2同master2安装配置ntp
(二)、安装MySQL服务
注意：如果有一个完整的mysql服务可以按照(三)进行复制
安装mysql文献：mysql的安装过程
(三)、部署剩下的mysql
master1：已安装mysql
注意： 直接把 master1 安装好的MySQL复制到 master2上
一定要关闭MySQL！！！！！！！！！！！
一定要关闭MySQL！！！！！！！！！！！
一定要关闭MySQL！！！！！！！！！！！
[root@master1 ~]# systemctl stop mysqld #复制前先关闭mysql 服务
-------------------------------------
mysql 主文件复制
[root@master1 ~]# for i in 10 11 12;do scp -r /usr/local/mysql/ [email protected].$i:/usr/local/mysql;done
mysql启动文件复制
[root@master1 ~]# for i in 10 11 12;do scp -r /usr/lib/systemd/system/mysqld.service [email protected].$i:/usr/lib/systemd/system/;done
mysql配置文件复制
[root@master1 ~]# for i in 10 11 12;do scp -r /etc/my.cnf [email protected].$i:/etc/;done
mysql系统文件复制
[root@master1 ~]# for i in 10 11 12;do scp -r /etc/init.d/mysql.server [email protected].$i:/etc/init.d/;done
master2 ：没有安装；进行部署
方法一：手动输入
[root@master2 ~]# yum -y install gcc gcc-c++ ncurses bison libgcrypt perl cmake ncurses-devel
...................
.........
..
[root@master2 ~]# groupadd mysql
[root@master2 ~]# useradd -r -g mysql mysql
[root@master2 ~]# chown -R mysql:mysql /usr/local/mysql
[root@master2 ~]# echo "export PATH=$PATH:/usr/local/mysql/bin/" >>/etc/profile
[root@master2 ~]# source /etc/profile
[root@master2 ~]# chkconfig --add mysql.server
[root@master2 ~]# systemctl start mysqld 或者 systemctl start mysql
-------------------------------------------------------------------
[root@master2 ~]# netstat -anptul | grep mysql
tcp6 0 0 :::3306 :::* LISTEN 68776/mysqld 方法二：懒人模式（复制粘贴完事）
echo '
yum -y install gcc gcc-c++ ncurses bison libgcrypt perl cmake ncurses-devel
groupadd mysql
useradd -r -g mysql mysql
chown -R mysql:mysql /usr/local/mysql
chkconfig --add mysql.server
systemctl start mysql
netstat -anptul | grep mysql
rm -rf jb.sh' > jb.sh
bash jb.sh
直接回车
echo "export PATH=$PATH:/usr/local/mysql/bin/" >>/etc/profile
source /etc/profileslave1(从1)、slave2(从2) 同上
完成后查看数据库是否启动：master1、master2、slave1、slave2的mysql数据库
1、 删除UUID文件
原因：mysql 有个uuid , 然而uuid 是唯一标识的，所以复制过来的uuid是一样的，只需要删除重启就可以了
[root@master2 ~]# find / -iname "auto.cnf"
/usr/local/mysql/data/auto.cnf
[root@master2 ~]# rm -rf /usr/local/mysql/data/auto.cnf
[root@master2 ~]# systemctl restart mysqld #重启
删除slave1、slave2的UUID
[root@slave1 ~]# rm -rf /usr/local/mysql/data/auto.cnf
[root@slave1 ~]# systemctl restart mysqld #重启
[root@slave2 ~]# rm -rf /usr/local/mysql/data/auto.cnf
[root@slave2 ~]# systemctl restart mysqld #重启（四）、 实现双主复制
1、 配置master1
echo '
server-id=1
log-bin=mysql-bin
log-slave-updates
sync_binlog=1
auto_increment_increment=2
auto_increment_offset=1
relay-log=relay1-log-bin
relay-log-index=slave-relay1-bin.index
' >> /etc/my.cnf
————————————————————说明——————————————————————————
server-id = 1 #每台 Mysql 主机的 server-id 不能相同
log_bin=mysql_bin #开启二进制日志用于主从数据复制
log_slave_updates=true #允许slave从master复制数据时可以写入到自己的二进制日志
sync_binlog=1 #主机每次提交事务的时候把二进制日志的内容同步到磁盘上，所以即使服务器崩溃，也会把时间写入到日志中
auto_increment_increment=2 #自增字段一次递增多少
auto_increment_offset=1 #自增字段的起始值
[root@master1 ~]# systemctl restart mysqld
[root@master1 ~]# mysql -uroot -p123.com
........
...
mysql> show master status;
+-----------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+-----------------+----------+--------------+------------------+-------------------+
| mysql-bin.000001 | 154 | | | |
+-----------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
mysql> grant replication slave on *.* to 'master'@'192.168.2.%' identified by '123.com';
Query OK, 0 rows affected, 1 warning (0.00 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
2、 配置master2(同步master1)
echo '
server-id=2
log-bin=mysql-bin
log-slave-updates
sync_binlog=1
auto_increment_increment=2
auto_increment_offset=1
relay-log=relay1-log-bin
relay-log-index=slave-relay1-bin.index
' >> /etc/my.cnf
[root@master2 ~]# systemctl restart mysqld
[root@master2 ~]# mysql -uroot -p123.com
.......
...
mysql> grant replication slave on *.* to 'master'@'192.168.2.%' identified by '123.com';
Query OK, 0 rows affected, 1 warning (0.00 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.01 sec)
mysql> change master to master_host='192.168.2.9',master_user='master',master_password='123.com',master_log_file='mysql-bin.000001',master_log_pos=154; #建议输入154
Query OK, 0 rows affected, 2 warnings (0.00 sec)
mysql> start slave;
Query OK, 0 rows affected (0.00 sec)
mysql> show slave status\G
*************************** 1. row ***************************
Slave_IO_State:
Master_Host: 192.168.2.9
Master_User: master
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000001
Read_Master_Log_Pos: 611
Relay_Log_File: relay1-log-bin.000002
Relay_Log_Pos: 776
Relay_Master_Log_File: mysql-bin.000001
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
.............
......4、 配置master1(同步master2)
在 master1 上配置
mysql> change master to master_host='192.168.2.10',master_user='master',master_password='123.com',master_log_file='mysql-bin.000001',master_log_pos=154; #写154
Query OK, 0 rows affected, 2 warnings (0.00 sec)
mysql> start slave;
Query OK, 0 rows affected (0.01 sec)
mysql> show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.2.10
Master_User: master
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000001
Read_Master_Log_Pos: 1068
Relay_Log_File: relay1-log-bin.000002
Relay_Log_Pos: 776
Relay_Master_Log_File: mysql-bin.000001
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
.....................
..........（五）、实现主从复制
1、配置 slave1从同步maser1
注意： 配置从服务器时从服务器不能同步旧数据
查看：maser1
mysql> flush logs;
Query OK, 0 rows affected (0.00 sec)
mysql> show master status;
+-----------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+-----------------+----------+--------------+------------------+-------------------+
| mysql-bin.000002 | 154 | | | |
+-----------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
slave1上配置
echo '
server-id=3
log-bin=mysql-bin
log-slave-updates
sync_binlog=1
auto_increment_increment=2
auto_increment_offset=1
relay-log=relay1-log-bin
relay-log-index=slave-relay1-bin.index
' >> /etc/my.cnf
[root@slave1 ~]# systemctl restart mysqld
[root@slave1 ~]# mysql -uroot -p123.com
mysql> change master to master_host='192.168.2.9',master_user='master',master_password='123.com',master_log_file='mysql-bin.000002',master_log_pos=154;
Query OK, 0 rows affected, 2 warnings (0.00 sec)
mysql> start slave;
Query OK, 0 rows affected (0.00 sec)
mysql> show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.2.9
Master_User: slave
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000001
Read_Master_Log_Pos: 154
Relay_Log_File: relay1-log-bin.000004
Relay_Log_Pos: 319
Relay_Master_Log_File: mysql-bin.000001
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
................
........
2、配置 slave2从同步maser2
注意： 配置从服务器时从服务器不能同步旧数据
查看 master2 的 Position
mysql> flush logs;
Query OK, 0 rows affected (0.00 sec)
mysql> show master status;
+-----------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+-----------------+----------+--------------+------------------+-------------------+
| mysql-bin.000002 | 154 | | | |
+-----------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
slave2上配置
echo '
server-id=4
log-bin=mysql-bin
log-slave-updates
sync_binlog=1
auto_increment_increment=2
auto_increment_offset=1
relay-log=relay1-log-bin
relay-log-index=slave-relay1-bin.index
' >> /etc/my.cnf
[root@slave2 ~]# systemctl restart mysqld
[root@slave2 ~]# mysql -uroot -p123.com
mysql> change master to master_host='192.168.2.10',master_user='master',master_password='123.com',master_log_file='mysql-bin.000002',master_log_pos=154;
Query OK, 0 rows affected, 2 warnings (0.01 sec)
mysql> start slave;
Query OK, 0 rows affected (0.00 sec)
mysql> show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.2.10
Master_User: master
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000002
Read_Master_Log_Pos: 154
Relay_Log_File: relay1-log-bin.000002
Relay_Log_Pos: 319
Relay_Master_Log_File: mysql-bin.000002
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
................
.......
如果I/O进程为NO 进行下面的操作
先重启服务在进行同步
systemctl restart mysqld
在主服务器上刷新日志
mysql> flush logs;
Query OK, 0 rows affected (0.00 sec)
在查看
mysql> show master status;
——————————————————————————————————————-
从服务器上执行
mysql> stop slave;
Query OK, 0 rows affected (0.00 sec)
mysql> change master to master_host='192.168.2.10',master_user='master',master_password='123.com',master_log_file='mysql-bin.000002',master_log_pos=154;
Query OK, 0 rows affected, 2 warnings (0.00 sec)
mysql> start slave;
Query OK, 0 rows affected (0.01 sec)
mysql> show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.2.10
Master_User: master
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000002
Read_Master_Log_Pos: 154
Relay_Log_File: relay1-log-bin.000002
Relay_Log_Pos: 319
Relay_Master_Log_File: mysql-bin.000002
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
.....................
..........（六）、测试
在 master1 上创建 user 库
mysql> create database user;
Query OK, 1 row affected (0.00 sec)
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
| user |
+--------------------+
5 rows in set (0.00 sec)
————————————————————————————————————————
master2
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
| user |
+--------------------+
5 rows in set (0.00 sec)
————————————————————————————————————————
slave1
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
| user |
+--------------------+
5 rows in set (0.00 sec)
————————————————————————————————————————
slave2
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
| user |
+--------------------+
5 rows in set (0.00 sec)
（七）、在monitor、master1、master2、slave1、slave2节点上安装mysql-mmm软件程序
1、在所有服务器上安装 MySQL-MMM
添加一个网卡 设置为桥接模式 后执行下面的命令
systemctl restart network
yum -y install wget
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
yum -y install epel-release
yum -y install mysql-mmm* 2、在 monitor 上对 MySQL-MMM 进行配置
[root@monitor ~]# cd /etc/mysql-mmm/
[root@monitor mysql-mmm]# vim mmm_common.conf
ctive_master_role writer
cluster_interface ens33 #修改网卡名称为内部网卡名称
pid_path /run/mysql-mmm-agent.pid
bin_path /usr/libexec/mysql-mmm/
replication_user master #数据库授权用户
replication_password 123.com #数据库授权密码
agent_user mmm_agent #代理用户的用户名
agent_password 12345 #代理用户的密码
ip 192.168.2.9 #修改ip
mode master
peer db2
ip 192.168.2.10 #修改ip
mode master
peer db1
ip 192.168.2.11 #修改ip
mode slave
ip 192.168.2.12 #修改ip
mode slave
hosts db1, db2
ips 192.168.2.100 #mater的虚拟IP
mode exclusive
hosts db3, db4 #修改
ips 192.168.2.101, 192.168.2.102 #slave1、slave2的虚拟IP
mode balanced
保存3、把配置文件复制到其它 4 台主机，所有主机配置文件内容都一样
[root@monitor mysql-mmm]# for i in 9 10 11 12;do scp mmm_common.conf [email protected].$i:/etc/mysql-mmm/;done 4、修改所有数据库服务器的代理配置文件 mmm_agent.conf
[root@master1 ~]# vim /etc/mysql-mmm/mmm_agent.conf
include mmm_common.conf
......
this db1
保存
——————————————————————————————————————
[root@master2 ~]# vim /etc/mysql-mmm/mmm_agent.conf
include mmm_common.conf
.....
this db2
保存
——————————————————————————————————————
[root@slave1 ~]# vim /etc/mysql-mmm/mmm_agent.conf
include mmm_common.conf
......
this db3
保存
——————————————————————————————————————
[root@slave2 ~]# vim /etc/mysql-mmm/mmm_agent.conf
include mmm_common.conf
......
this db4
保存5、在 monitor 监控服务器上修改监控配置文件 mmm_mon.conf
[root@monitor ~]# cd /etc/mysql-mmm/
[root@monitor mysql-mmm]# ls
mmm_agent.conf mmm_common.conf mmm_mon.conf mmm_mon_log.conf mmm_tools.conf
[root@monitor mysql-mmm]# cp mmm_mon.conf{,.bak}
[root@monitor mysql-mmm]# ls
mmm_agent.conf mmm_common.conf mmm_mon.conf mmm_mon.conf.bak mmm_mon_log.conf mmm_tools.conf
[root@monitor mysql-mmm]# vim mmm_mon.conf
include mmm_common.conf
ip 127.0.0.1
pid_path /run/mysql-mmm-monitor.pid
bin_path /usr/libexec/mysql-mmm
status_path /var/lib/mysql-mmm/mmm_mond.status
ping_ips 192.168.2.9,192.168.10,192.168.11,192.168.2.12 #指定数据库IP
auto_set_online 10 #指定自动上线时间
.................
......
monitor_user mmm_monitor #指定用户
monitor_password 12345 #指定密码
debug 0
保存6、在master 数据库上为 mmm_agent（代理进程）和 mmm_moniter（监控进程） 授权
grant super, replication client, process on *.* to 'mmm_agent'@'192.168.2.%' identified by '12345';
grant replication client on *.* to 'mmm_monitor'@'192.168.2.%' identified by '12345';
flush privileges; 7、monitor、master1、master2、slave1、slave2 启动 mysql-mmm
monitor 上启动mysql-mmm-monitor
[root@monitor ~]# systemctl start mysql-mmm-monitor.service master1、master2、slave1、slave2 启动 mysql-mmm-agent
systemctl start mysql-mmm-agent.service
systemctl enable mysql-mmm-agent.service （八）、在 monitor 服务器上进行测试群集
1、查看节点情况
[root@monitor ~]# mmm_control show
db1(192.168.2.9) master/ONLINE. Roles: writer(192.168.2.100)
db2(192.168.2.10) master/ONLINE. Roles:
db3(192.168.2.11) slave/ONLINE. Roles: reader(192.168.2.102)
db4(192.168.2.12) slave/ONLINE. Roles: reader(192.168.2.101)
| ONLINE. Roles | 在线节点 |
| HARD_OFFLINE. Roles | ping不通 或者 mysql连接中断，会导致hard_offline状态 |
| admin_offline | 手动下线的状态 |
2、查看监控情况是否都完善，全为OK表示没有问题
[root@monitor ~]# mmm_control checks all
db4 ping [last change: 2021/12/21 21:49:40] OK
db4 mysql [last change: 2021/12/21 21:49:40] OK
db4 rep_threads [last change: 2021/12/21 21:49:40] OK
db4 rep_backlog [last change: 2021/12/21 21:49:40] OK: Backlog is null
db2 ping [last change: 2021/12/21 21:49:40] OK
db2 mysql [last change: 2021/12/21 21:49:40] OK
db2 rep_threads [last change: 2021/12/21 21:49:40] OK
db2 rep_backlog [last change: 2021/12/21 21:49:40] OK: Backlog is null
db3 ping [last change: 2021/12/21 21:49:40] OK
db3 mysql [last change: 2021/12/21 21:49:40] OK
db3 rep_threads [last change: 2021/12/21 21:49:40] OK
db3 rep_backlog [last change: 2021/12/21 21:49:40] OK: Backlog is null
db1 ping [last change: 2021/12/21 21:49:40] OK
db1 mysql [last change: 2021/12/21 21:49:40] OK
db1 rep_threads [last change: 2021/12/21 21:49:40] OK
db1 rep_backlog [last change: 2021/12/21 21:49:40] OK: Backlog is null
3、指定绑定 VIP 的主机
——————————————————修改前
[root@monitor ~]# mmm_control show
db1(192.168.2.9) master/ONLINE. Roles: writer(192.168.2.100)
db2(192.168.2.10) master/ONLINE. Roles:
db3(192.168.2.11) slave/ONLINE. Roles: reader(192.168.2.102)
db4(192.168.2.12) slave/ONLINE. Roles: reader(192.168.2.101)
[root@monitor ~]# mmm_control move_role writer db2 #修改writer的主机
OK: Role 'writer' has been moved from 'db1' to 'db2'. Now you can wait some time and check new roles info!
——————————————————修改后
[root@monitor ~]# mmm_control show
db1(192.168.2.9) master/ONLINE. Roles:
db2(192.168.2.10) master/ONLINE. Roles: writer(192.168.2.100)
db3(192.168.2.11) slave/ONLINE. Roles: reader(192.168.2.102)
db4(192.168.2.12) slave/ONLINE. Roles: reader(192.168.2.101)
——————————————————修改回来
[root@monitor ~]# mmm_control move_role writer db1
OK: Role 'writer' has been moved from 'db2' to 'db1'. Now you can wait some time and check new roles info!
[root@monitor ~]# mmm_control show
db1(192.168.2.9) master/ONLINE. Roles: writer(192.168.2.100)
db2(192.168.2.10) master/ONLINE. Roles:
db3(192.168.2.11) slave/ONLINE. Roles: reader(192.168.2.102)
db4(192.168.2.12) slave/ONLINE. Roles: reader(192.168.2.101)
（九）、故障测试
1、停止 master01 确认 VIP 是否移动到 master02 上
注意：master1 主服务器恢复服务后，不会抢占
[root@master1 ~]# systemctl stop mysqld
[root@master1 ~]# netstat -anptu|grep mysql
[root@master1 ~]#
[root@monitor ~]# mmm_control show
db1(192.168.2.9) master/HARD_OFFLINE. Roles:
db2(192.168.2.10) master/ONLINE. Roles: writer(192.168.2.100)
db3(192.168.2.11) slave/ONLINE. Roles: reader(192.168.2.102)
db4(192.168.2.12) slave/ONLINE. Roles: reader(192.168.2.101)
[root@master1 ~]# systemctl start mysqld
结论：当master1 宕机之后，writer会自动切换到master2上，实现了高可用
2、 停止一台从服务器，另一台将接管两个虚拟IP，以保证业务不停止
[root@slave1 ~]# systemctl stop mysqld
[root@monitor ~]# mmm_control show
db1(192.168.2.9) master/ONLINE. Roles:
db2(192.168.2.10) master/ONLINE. Roles: writer(192.168.2.100)
db3(192.168.2.11) slave/HARD_OFFLINE. Roles:
db4(192.168.2.12) slave/ONLINE. Roles: reader(192.168.2.101), reader(192.168.2.102) #db4接管了两个VIP
[root@slave1 ~]# systemctl start mysqld（十）、客户端测试
1、在 master1、master2、slave1、slave2 上配置VIP地址
[root@master1 ~]# ip addr add 192.168.2.100/24 dev ens33
[root@master2 ~]# ip addr add 192.168.2.100/24 dev ens33
[root@slave1 ~]# ip addr add 192.168.2.101/24 dev ens33
[root@slave2 ~]# ip addr add 192.168.2.102/24 dev ens33
删除 VIP
[root@slave2 ~]# ip addr del 192.168.2.102/32 dev ens33
如果没有删除就查看子网掩码是多少位
2、在 master1 服务器上为 monitor 服务器地址授权登录
[root@master1 ~]# systemctl start mysqld
......
..
mysql> grant all on *.* to 'jl'@'192.168.2.%' identified by '123456'; #授权monitor服务器上的 jl 用户远程登录权限
Query OK, 0 rows affected, 1 warning (0.01 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
3、在 monitor 服务器上使用 VIP 登录进行测试
[root@monitor ~]# yum install -y mariadb-server mariadb
.......
..
[root@monitor ~]# systemctl start mariadb.service
[root@monitor ~]# mysql -ujl -p123456 -h 192.168.2.100
...............
.....
MySQL [(none)]> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
| user |
+--------------------+
5 rows in set (0.00 sec)
MySQL [(none)]> create database aaa;
Query OK, 1 row affected (0.00 sec)
MySQL [(none)]> quit
Bye
[root@monitor ~]# mysql -ujl -p123456 -h 192.168.2.102
..........
....
MySQL [(none)]> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| aaa |
| mysql |
| performance_schema |
| sys |
| user |
+--------------------+
6 rows in set (0.00 sec)
4、关闭slave1和slave2节点的写功能，让其只能读取
没有关闭前
[root@monitor ~]# mysql -ujl -p123456 -h 192.168.2.102
.............
MySQL [(none)]> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| aaa |
| mysql |
| performance_schema |
| sys |
| user |
+--------------------+
6 rows in set (0.00 sec)
MySQL [(none)]> create database user111;
Query OK, 1 row affected (0.00 sec)
MySQL [(none)]> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| aaa |
| mysql |
| performance_schema |
| sys |
| user |
| user111 |
+--------------------+
7 rows in set (0.00 sec)
在 slave1和slave2 上配置
echo 'read_only=1'>>/etc/my.cnf
重启mysql
systemctl restart mysqld
————————————————————————————————————————
master1 创建一个用户
mysql> grant select,insert on *.* to 'yg'@'192.168.2.%' identified by "123456";
Query OK, 0 rows affected, 1 warning (0.01 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
——————————————————————————————
客户端测试
[root@monitor ~]# mysql -uyg -p123456 -h 192.168.2.102
...........
MySQL [(none)]> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| aaa |
| mysql |
| performance_schema |
| sys |
| user |
| user111 |
+--------------------+
7 rows in set (0.00 sec)
MySQL [(none)]> create database bbbbb;
ERROR 1290 (HY000): The MySQL server is running with the --read-only option so it cannot execute this statement