keepalived 高可用主备VIP快速部署

王忘杰

发布于 2026-03-18 12:32:08

900

IP规划

192.168.4.20 VIP虚拟地址
192.168.4.21 keepalived1
192.168.4.22 keepalived2

网卡为 ens192

系统为Anolis8 龙蜥8

关闭防火墙

systemctl stop firewalld && systemctl disable firewalld

软件安装

主机1 192.168.4.21 keepalived1 安装

yum install -y keepalived

配置文件备份

cp /etc/keepalived/keepalived.conf /etc/keepalived/keepalived.conf.bak

编辑 vi /etc/keepalived/keepalived.conf


! Configuration File for keepalived

global_defs {
   router_id keepalived1   #只是名字而已，辅节点改为keepalived2（两个名字一定不能一样）
}

vrrp_instance VI_1 {
    state MASTER        #定义主还是备，备用的话写backup
    interface ens192     #VIP绑定接口
    virtual_router_id #整个集群的调度器一致（在同一个集群）
    priority #（优先权）back改为50（50一间隔）
    advert_int #发包
    authentication {
        auth_type PASS      #主备节点认证
        auth_pass 
}
    virtual_ipaddress {
192.168.4.20/24    #VIP（自己网段的）
}
}

主机2 192.168.4.22 keepalived2 安装软件

yum install -y keepalived

配置文件备份

cp /etc/keepalived/keepalived.conf /etc/keepalived/keepalived.conf.bak

编辑 vi /etc/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs {
   router_id keepalived2
}
vrrp_instance VI_1 {
    state BACKUP    #设置为backup
    interface ens192
    nopreempt        #设置到back上面，不抢占资源
    virtual_router_id 
    priority #辅助改为50
    advert_int #检测间隔1s
    authentication {
        auth_type PASS
        auth_pass #认证类型和密码主备一样，要不然无法互相认证
}
    virtual_ipaddress {
192.168.4.20/24   #抢占的VIP也一样
}
}

启动服务

systemctl enable --now keepalived

重启主机1，VIP自动漂移到主机2，启动主机1，VIP漂回来

配置业务

在两台主机上安装nginx

yum install nginx -y
systemctl enable --now nginx

两台主机显示不同网页主机1

echo"keepalived1 nginx"> /usr/share/nginx/html/index.html

主机2

echo"keepalived2 nginx"> /usr/share/nginx/html/index.html

两台主机访问nginx业务正常

配置nginx高可用检测

两台主机均编写脚本 vi /etc/keepalived/check_nginx.sh 通过端口监听判断业务是否正常，几乎适用于所有业务，如MQ、nginx、OBProxy等等

#!/bin/bash

# 检查80端口是否有监听
if ss -tuln |grep -q ':80\b';then
exit# 检测成功，返回0
else
exit# 检测失败，返回1
fi

配置keepalived1 192.168.4.21 keepalived1 执行权限

chmod +x /etc/keepalived/check_nginx.sh

编辑配置文件 vi /etc/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs {
   router_id keepalived1   #只是名字而已，辅节点改为keepalived2（两个名字一定不能一样）
}
vrrp_script check_nginx {
   script "/etc/keepalived/check_nginx.sh"
   interval #每2秒执行一次
}

vrrp_instance VI_1 {
    state MASTER        #定义主还是备，备用的话写backup
    interface ens192     #VIP绑定接口
    virtual_router_id #整个集群的调度器一致（在同一个集群）
    priority #（优先权）back改为50（50一间隔）
    advert_int #发包
    authentication {
        auth_type PASS      #主备节点认证
        auth_pass 
}
    virtual_ipaddress {
192.168.4.20/24    #VIP（自己网段的）
}
    track_script {
        check_nginx
}
}

配置keepalived2 192.168.4.22 keepalived2 执行权限

chmod +x /etc/keepalived/check_nginx.sh

编辑配置文件 vi /etc/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs {
   router_id keepalived2
}
vrrp_script check_nginx {
   script "/etc/keepalived/check_nginx.sh"
   interval #每2秒执行一次
}
vrrp_instance VI_1 {
    state BACKUP    #设置为backup
    interface ens192
    nopreempt        #设置到back上面，不抢占资源
    virtual_router_id 
    priority #辅助改为50
    advert_int #检测间隔1s
    authentication {
        auth_type PASS
        auth_pass #认证类型和密码主备一样，要不然无法互相认证
}
    virtual_ipaddress {
192.168.4.20/24   #抢占的VIP也一样
}
    track_script {
        check_nginx
}
}

改完配置文件两台主机都需要重启keepalived服务

关闭主机1的nginx服务，VIP自动漂移到主机2，启动主机1的nginx服务，VIP漂回来

配置为单播，抵御脑裂

配置keepalived1 192.168.4.21 keepalived1 编辑配置文件 vi /etc/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs {
   router_id keepalived1   #只是名字而已，辅节点改为keepalived2（两个名字一定不能一样）
}
vrrp_script check_nginx {
   script "/etc/keepalived/check_nginx.sh"
   interval #每2秒执行一次
}

vrrp_instance VI_1 {
    state MASTER        #定义主还是备，备用的话写backup
    interface ens192     #VIP绑定接口
    virtual_router_id #整个集群的调度器一致（在同一个集群）
    priority #（优先权）back改为50（50一间隔）
    advert_int #发包
    authentication {
        auth_type PASS      #主备节点认证
        auth_pass 
}
    unicast_src_ip 192.168.4.21 #本机ip
    unicast_peer {
192.168.4.22 #其他机器ip，可多个
}
    virtual_ipaddress {
192.168.4.20/24    #VIP（自己网段的）
}
    track_script {
        check_nginx
}
}

配置keepalived2 192.168.4.22 keepalived2 编辑配置文件 vi /etc/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs {
   router_id keepalived2
}
vrrp_script check_nginx {
   script "/etc/keepalived/check_nginx.sh"
   interval #每2秒执行一次
}
vrrp_instance VI_1 {
    state BACKUP    #设置为backup
    interface ens192
    nopreempt        #设置到back上面，不抢占资源
    virtual_router_id 
    priority #辅助改为50
    advert_int #检测间隔1s
    authentication {
        auth_type PASS
        auth_pass #认证类型和密码主备一样，要不然无法互相认证
}
    unicast_src_ip 192.168.4.22 #本机ip
    unicast_peer {
192.168.4.21 #其他机器ip，可多个
}
    virtual_ipaddress {
192.168.4.20/24   #抢占的VIP也一样
}
    track_script {
        check_nginx
}
}

改完配置文件两台主机都需要重启keepalived服务