MySQL数据库高可用安装配置

一、分析

• 本文所说的高可用

本文所说的MySQL高可用主要是通过Keepalived来实现多个节点的服务的可用性检测和故障转移，对外提供VIP地址供客户端连接，由keepalived根据服务的状态，负责将vip漂移到真实可用的机器上，从而实现服务的高可用。

• 架构

两台MySQL或者多台做主主互备，VIP对外提供连接

机器	IP/VIP	组件	版本
mysql1	10.10.0.1	MySQL/Keepalived	5.7.25/2.0.20
mysql2	10.10.0.2	MySQL/Keepalived	5.7.25/2.0.20
	10.10.0.3

二、基础环境

1、修改主机名及hosts

hostnamectl set-hostname mysql1
hostnamectl set-hostname mysql2
...

cat >> /etc/hosts <<EOF
10.10.0.1 mysql1
10.10.0.2 mysql2
EOF

2、修改系统进程打开最大文件数

echo "*   soft    nofile  65535" >> /etc/security/limits.conf
echo "*   hard    nofile  65535" >> /etc/security/limits.conf

3、关闭防火墙及selinux

systemctl stop firewalld && systemctl disable firewalld

setenforce 0

sed -i 's/^SELINUX=.*/SELINUX=disabled/' /etc/selinux/config

三、MySQL

分别在mysql1及mysql2节点安装同一版本的mysql，本文以5.7.25为例说明

1、卸载mariadb数据库

rpm -qa | grep mariadb

yum -y remove mariadb-libs-5.5.52-1.el7.x86_64

2、依赖检查安装

• 安装MySQL需要libaio组件，默认的操作系统自带，可检查一下，如果没有需自行安装

rpm -qa | grep libaio

• 安装net-tools组件，默认系统没有需自行安装

rpm -ivh net-tools-2.0-0.24.20131004git.el7.x86_64.rpm

3、解压安装MySQL

仅安装必须的几个包即可

tar -xvf mysql-5.7.25-1.el7.x86_64.rpm-bundle.tar

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-client-5.7.25-1.el7.x86_64.rpm
rpm -ivh mysql-community-server-5.7.25-1.el7.x86_64.rpm

4、修改配置文件

vim /etc/my.cnf

default-storage-engine = innodb
innodb_file_per_table
collation-server = utf8_general_ci
init-connect = 'SET NAMES utf8'
character-set-server = utf8
max_allowed_packet = 500M
innodb_buffer_pool_size = 512M
max_connections = 20000
expire_logs_days = 10
max_binlog_size = 512M

5、初始化并启动数据库

mysqld --initialize

chown mysql:mysql /var/lib/mysql -R

systemctl enable mysqld && systemctl start mysqld

6、修改密码及权限添加

默认MySQL安装完有一个临时密码，可通过这个临时密码修改我们数据库的密码

cat /var/log/mysqld.log | grep password

通过临时密码登陆MySQL，修改密码

mysql -uroot -pSlg.ieA+j8Dn

set password for root@localhost = password('Test1234!');

添加远程登录权限

GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY 'Test1234\!';
FLUSH PRIVILEGES;

四、主主互备

1、主机mysql1配置

创建用于存放bin日志文件的目录

mkdir -p /usr/local/mysql

创建bin日志文件并修改权限及用户属组

touch /usr/local/mysql/mysql-bin.log

chmod 777 /usr/local/mysql/mysql-bin.log && chown -R mysql:mysql /usr/local/mysql/

修改配置文件my.cnf

vim /etc/my.cnf

log_bin = /usr/local/mysql/mysql-bin.log
server_id = 1
binlog_ignore_db=mysql
auto_increment_increment = 2
auto_increment_offset = 1

重启MySQL

service mysqld stop && service mysqld start

登陆MySQL配置mysql2的同步账号

mysql -uroot -p

grant replication slave on *.* to'slave'@'10.10.0.2' identified by 'Test1234!';

FLUSH PRIVILEGES;

2、主机mysql2配置

创建用于存放bin日志文件的目录

mkdir -p /usr/local/mysql

创建bin日志文件并修改权限及用户属组

touch /usr/local/mysql/mysql-bin.log

chmod 777 /usr/local/mysql/mysql-bin.log && chown -R mysql:mysql /usr/local/mysql/

修改配置文件my.cnf

vim /etc/my.cnf

log_bin = /usr/local/mysql/mysql-bin.log
server_id = 2
binlog_ignore_db=mysql
auto_increment_increment = 2
auto_increment_offset = 1

重启MySQL

service mysqld stop && service mysqld start

登陆MySQL配置mysql1的同步账号

mysql -uroot -p

grant replication slave on *.* to'slave'@'10.10.0.1' identified by 'Test1234!';

FLUSH PRIVILEGES;

3、mysql1配置

重启并登陆MySQL

service mysqld stop && service mysqld start

mysql -uroot -p

配置salve

stop slave;

change master to master_host='10.10.0.2',master_user='slave',master_password='Test1234!';

start slave;

4、mysql2配置

重启并登陆MySQL

service mysqld stop && service mysqld start

mysql -uroot -p

配置salve

stop slave;

change master to master_host='10.10.0.1',master_user='slave',master_password='Test1234!';

start slave;

5、查看主主互备状态

分别登陆mysql1及mysql2，查看互备状态

show slave status \G;

重点关注项为：

Slave_IO_State: Waiting for master to send event
Slave_IO_Running: Yes
Slave_SQL_Running: Yes

五、Keepalived

在mysql1和mysql2分别安装keepalived

1、安装依赖

yum -y install openssl-devel

2、获取Keepalived

https://www.keepalived.org/download.html

3、安装

tar -xvf keepalived-2.0.20.tar.gz && rm -rf keepalived-2.0.20.tar.gz && cd keepalived-2.0.20

./configure --prefix=/usr/local/keepalived

make && make install

4、版本查看

/usr/local/keepalived/sbin/keepalived -v

5、配置文件

• 配置文件参数详解

https://www.cnblogs.com/arjenlee/p/9258188.html

• 创建配置文件目录及配置文件

mkdir -p /etc/keepalived

自带配置文件：/usr/local/keepalived/etc/keepalived/keepalived.conf，可作参考，这里直接创建新的配置文件即可

• mysql1服务器

vim /etc/keepalived/keepalived.conf


global_defs {
    router_id mysql1
}

vrrp_script mysql_check {
   script "/usr/local/keepalived/check.sh"
   interval 2
   weight -20
}

vrrp_instance VI_1 {
    state MASTER
    interface eth0
    virtual_router_id 51
    priority 80
    advert_int 1
    
    track_script {
       mysql_check
    }
    authentication {
        auth_type PASS
        auth_pass 123456
    }
    virtual_ipaddress {
        10.10.0.3
    }
}

• mysql2服务器

vim /etc/keepalived/keepalived.conf


global_defs {
    router_id mysql2
}

vrrp_script mysql_check {
   script "/usr/local/keepalived/check.sh"
   interval 2
   weight：-20
}

vrrp_instance VI_1 {
    state BACKUP
    interface eth0
    virtual_router_id 51
    priority 70
    advert_int 1
    
    track_script {
       mysql_check
    }
    authentication {
        auth_type PASS
        auth_pass 123456
    }
    virtual_ipaddress {
        10.10.0.3
    }
}

• vrrp_script：检查脚本，检查haproxy状态，如果挂掉，VIP漂移
• script：脚本命令
• interval：检查间隔
• weight：权重
• state：标记该节点是master还是backup
• interface：配置VIP绑定的网卡，这里使用和外网通信的网卡
• virtual_router_id：取1-255之间的值，主备需要相同，这样才能成为一个组
• priority：权重，数值高的主机是master，所以主节点要比从节点大，这是影响主备的关键
• advert_int：主备之间通讯的间隔秒数，用于判断主节点是否存活
• auth_type：进行安全认证的方式，PASS或者AH方式，推荐PASS
• auth_pass：PASS的密码
• virtual_ipaddress：VIP地址，最多可以写20个，keepalive启动后会自动配置该VIP

6、检测脚本

放置到配置文件所指定目录并添加权限

vim /usr/local/keepalived/check.sh

#!/bin/bash
count=`ps aux | grep -v grep | grep mysqld | wc -l`
if [ $count -eq 0 ]; then
    exit 1
else
    exit 0
fi

chmod +x /usr/local/keepalived/check.sh

7、启动

• 创建service文件

cat > /etc/systemd/system/keepalived.service <<EOF
[Unit]
Description=LVS and VRRP High Availability Monitor
After=syslog.target network-online.target

[Service]
Type=forking
KillMode=process
ExecStart=/usr/local/keepalived/sbin/keepalived

[Install]
WantedBy=multi-user.target
EOF

systemctl daemon-reload

systemctl enable keepalived && systemctl start keepalived && systemctl status keepalived

8、主从查看

在主节点查看网络信息，可以发现我们设置的VIP，当主节点或者MySQL任意一个挂掉时，VIP都会自动漂移到从节点实现mysql的高可用