参考文章：
https://blog.csdn.net/f18770366447/article/details/80703347
https://www.cnblogs.com/benjamin77/p/8682360.html
https://www.xiaocoder.com/2017/03/17/mysql-installation-guide/
https://blog.csdn.net/hongguo_cheng/article/details/80293588
1，配置环境
两个节点，vcpu8个，内存8G，磁盘16G
操作系统：Centos7.5最小化安装
A节点IP地址：172.16.103.14 node1
B节点IP地址：172.16.103.15 node2
VIP：172.16.103.16
关闭selinux和防火墙
2，查看是否已经存在数据库，如果已经存在则卸载
rpm -qa |grep mysql //查看是否mysql数据库
rpm -qa |grep mari //查看是否又mariadb数据库
rpm -e --nodeps mariadb-libs-5.5.56-2.el7.x86_64 //卸载mariadb数据库，包的名字一定要是grep出来的全名
3，安装依赖包
yum install -y net-tools perl
4，下载mysql包，上传解压，安装。
下载5.7的mysql 社区版包
https://cdn.mysql.com//Downloads/MySQL-5.7/mysql-5.7.25-1.el7.x86_64.rpm-bundle.tar
上传到/software目录下，解压
tar -xvf mysql-5.7.25-1.el7.x86_64.rpm-bundle.tar
安装
rpm -ivh mysql-community-common-5.7.25-1.el7.x86_64.rpm
rpm -ivh mysql-community-libs-5.7.25-1.el7.x86_64.rpm
rpm -ivh mysql-community-libs-compat-5.7.25-1.el7.x86_64.rpm
rpm -ivh mysql-community-client-5.7.25-1.el7.x86_64.rpm
rpm -ivh mysql-community-server-5.7.25-1.el7.x86_64.rpm
5，创建目录，添加用户，设置所属
mkdir -p /data/mysql/{data,tmp,log}
groupadd mysql
useradd -g mysql mysql
chown -R mysql:mysql /data/mysql/{data,tmp,log}
6，修改配置文件
vi /etc/my.cnf
#配置文件内容开始
[client]
port = 3306
socket = /data/mysql/tmp/mysql.sock
default-character-set = utf8mb4
[mysqld]
port = 3306
datadir = /data/mysql/data
pid-file = /data/mysql/tmp/mysqld.pid
socket = /data/mysql/tmp/mysql.sock
log-error = /data/mysql/log/error.log
character_set_server = utf8mb4
user = mysql
bind-address = *
server-id = 1 #节点2修改为2
symbolic-links=1
connect_timeout = 3600
wait_timeout = 3600
interactive_timeout = 3600
explicit_defaults_for_timestamp = true
log-bin = mysql-bin
sync_binlog = 1
binlog_checksum = none
binlog_format = mixed
auto-increment-increment = 2
auto-increment-offset = 1 #节点2修改为2
slave-skip-errors = all
#配置文件内容结束
启动服务
systemctl start mysqld
8，登陆数据库并做相关配置获取mysql安装时的默认密码
MySQL_PASS=$(cat /data/mysql/log/error.log | grep "A temporary password" | awk '{print $NF}')
使用改密码登陆数据库
mysql -u root -p"${MySQL_PASS}"
设置新密码为：Admin123,.
mysql> SET PASSWORD='Admin123,.';
开启任意主机可使用root用户访问所有库，密码为ADmin123,.
mysql> GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY 'ADmin123,.' WITH GRANT OPTION;
9，节点2执行上面1-8步骤，然后添加同步账户
10，添加同步账户，账户名为repl，密码为ADMin123,.
节点1mysql> grant replication slave on *.* to 'repl'@'172.16.103.15' identified by 'ADMin123,.';
节点2mysql> grant replication slave on *.* to 'repl'@'172.16.103.14' identified by 'ADMin123,.';
使配置立即生效
mysql> flush privileges;
11，查看的主库状态
节点1
show master status;
节点2
show master status;
12，开始同步
节点1操作，change master 语句中填写节点2的信息
mysql> unlock tables;
mysql> stop slave;
mysql> change master to master_host='172.16.103.15',master_user='repl',master_password='ADMin123,.',master_log_file='mysql-bin.000003',master_log_pos=150;
mysql> start slave;
mysql> show slave status G
具体过程
执行show slave status G之后看到以下内容为正常！
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
节点2操作
节点2操作，change master 语句中填写节点1的信息
mysql> unlock tables;
mysql> stop slave;
mysql> change master to master_host='172.16.103.14',master_user='repl',master_password='ADMin123,.',master_log_file='mysql-bin.000002',master_log_pos=2848;
mysql> start slave;
mysql> show slave status G
执行show slave status G之后看到以下内容为正常！
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
13，主主同步测试
在节点1登陆数据库，创建数据库，创建表，插入数据，然后在节点2上查看。
解锁表
unlock tables;
创建ceshiku数据库
create database ceshiku;
使用ceshik数据库
use ceshiku;
创建表，名字为哈哈，后面是列是数据类型
create table if not exists haha ( id int(10) PRIMARY KEY AUTO_INCREMENT, name varchar(50) NOT NULL);
插入数据
insert into haha values(2,'guojing');
插入数据
insert into haha values(1,"huangrong");
查询表haha的所有数据
select * from haha;
以下是图形操作的过程
在节点2上查看同步过来的信息
select * from ceshiku.haha;
14，安装keepalived软件包，并集成成系统服务（两个节点都执行）
keepalived包的下载地址
http://www.keepalived.org/software/keepalived-1.3.5.tar.gz
所有版本
https://www.keepalived.org/download.html
上传keepalive包到/usr/local/src/下，安装依赖包，解压缩软件包，编译，安装
安装依赖包
yum install -y openssl-devel gcc
进入目录解压缩
cd /usr/local/src/
tar -zxvf keepalived-1.3.5.tar.gz
进入目录，编译，安装
cd keepalived-1.3.5
./configure --prefix=/usr/local/keepalived
make && make install
拷贝相关目录和文件的到系统目录
cp /usr/local/src/keepalived-1.3.5/keepalived/etc/init.d/keepalived /etc/rc.d/init.d/
cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
mkdir -p /etc/keepalived/
cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/
cp /usr/local/keepalived/sbin/keepalived /usr/local/sbin/
echo "/etc/init.d/keepalived start" >> /etc/rc.local
15，配置keepaived服务
节点1配置
备份原有的conf文件
cp /etc/keepalived/keepalived.conf /etc/keepalived/keepalived.conf.bak
vi /etc/keepalived/keepalived.conf #删除配置文件中的所有内容，加入以下内容
#配置文件内容开始
! Configuration File for keepalived
global_defs {
notification_email {
ops@wangshibo.cn
tech@wangshibo.cn
}
notification_email_from ops@wangshibo.cn
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id MASTER-HA
}
vrrp_script chk_mysql_port { #检测mysql服务是否在运行。有很多方式，比如进程，用脚本检测等等
script "/opt/chk_mysql.sh" #这里通过脚本监测
interval 2 #脚本执行间隔，每2s检测一次
weight -5 #脚本结果导致的优先级变更，检测失败（脚本返回非0）则优先级 -5
fall 2 #检测连续2次失败才算确定是真失败。会用weight减少优先级（1-255之间）
rise 1 #检测1次成功就算成功。但不修改优先级
}
vrrp_instance VI_1 {
state MASTER
interface ens192 #指定自己的网卡接口和IP
mcast_src_ip 172.16.103.14
virtual_router_id 51 #路由器标识，MASTER和BACKUP必须是一致的
priority 101 #定义优先级，数字越大，优先级越高，在同一个vrrp_instance下，MASTER的优先级必须大于BACKUP的优先级。这样MASTER故障恢复后，就可以将VIP资源再次抢回来
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
172.16.103.16
}
track_script {
chk_mysql_port
}
}
#配置文件内容结束
编写检测脚本，KeepAlived做心跳检测，如果Master的MySQL服务挂了(3306端口挂了),那么它就会选择自杀。Slave的KeepAlived通过心跳检测发现这个情况，就会将VIP的请求接管
vi /opt/chk_mysql.sh
#脚本内容开始
#!/bin/bash
counter=$(netstat -na|grep "LISTEN"|grep "3306"|wc -l)
if [ "${counter}" -eq 0 ]; then
/etc/init.d/keepalived stop
fi
#脚本内容结束
给脚本添加执行权限
chmod 755 /opt/chk_mysql.sh
启动keepalived服务
systemctl start keepalived
如果启动延迟最终导致启动失败，最后keepalived的状态是下图所示。
然后查看日志：
tail -f /var/log/messages
Apr 16 18:35:18 node1 systemd: PID file /usr/local/keepalived/var/run/keepalived.pid not readable (yet?) after start.
Apr 16 18:36:48 node1 systemd[1]: keepalived.service start operation timed out. Terminating.
Apr 16 18:36:48 node1 systemd[1]: Failed to start LVS and VRRP High Availability Monitor.
Apr 16 18:36:48 node1 systemd[1]: Unit keepalived.service entered failed state.
Apr 16 18:36:48 node1 systemd[1]: keepalived.service failed.
这种情况下vip确实已经生效了，但是keepalived服务也没有正常开启，解决办法是编辑keepalived服务的pid文件指向的位置
vi /usr/lib/systemd/system/keepalived.service
PIDFile=/var/run/keepalived.pid
然后重载服务，重启服务
systemctl daemon-reload
systemctl start keepalived
systemctl status keepalived
节点2配置参照节点1配置，只是keepalived.conf配置文件的内容不通，具体内容如下
#配置文件内容开始
! Configuration File for keepalived
global_defs {
notification_email {
ops@wangshibo.cn
tech@wangshibo.cn
}
notification_email_from ops@wangshibo.cn
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id MASTER-HA
}
vrrp_script chk_mysql_port { #检测mysql服务是否在运行。有很多方式，比如进程，用脚本检测等等
script "/opt/chk_mysql.sh" #这里通过脚本监测
interval 2 #脚本执行间隔，每2s检测一次
weight -5 #脚本结果导致的优先级变更，检测失败（脚本返回非0）则优先级 -5
fall 2 #检测连续2次失败才算确定是真失败。会用weight减少优先级（1-255之间）
rise 1 #检测1次成功就算成功。但不修改优先级
}
vrrp_instance VI_1 {
state BACKUP
interface ens192 #指定自己的网卡接口和IP
mcast_src_ip 172.16.103.15
virtual_router_id 51 #路由器标识，MASTER和BACKUP必须是一致的
priority 100 #定义优先级，数字越大，优先级越高，在同一个vrrp_instance下，MASTER的优先级必须大于BACKUP的优先级。这样MASTER故障恢复后，就可以将VIP资源再次抢回来
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
172.16.103.16
}
track_script {
chk_mysql_port
}
}
#配置文件内容结束
同样参照节点1的配置，节点2同样需要配置检测脚本
vi /opt/chk_mysql.sh
#脚本内容开始
#!/bin/bash
counter=$(netstat -na|grep "LISTEN"|grep "3306"|wc -l)
if [ "${counter}" -eq 0 ]; then
/etc/init.d/keepalived stop
fi
#脚本内容结束
设置权限
chmod 755 /opt/chk_mysql.sh
同样要修改keepalived服务的pid文件指向的位置
vi /usr/lib/systemd/system/keepalived.service
PIDFile=/var/run/keepalived.pid
启动服务
systemctl start keepalived
检查keepalived的状态
systemctl status keepalived
可以看到该节点被定义为从节点了。
至此，使用navicat客户端连接vip即可，vip可以对外提供服务了。