keepalived知识点详解

一、高可用集群

1.1集群类型

LB：Load Balance 负载均衡

LVS/HAProxy/nginx（http/upstream, stream/upstream）

HA：High Availability 高可用集群数据库、Redis

SPoF: Single Point of Failure，解决单点故障

HPC：High Performance Computing 高性能集群

1.2系统可用性

SLA：Service-Level Agreement 服务等级协议（提供服务的企业与客户之间就服务的品质、水准、性能等方面所达成的双方共同认可的协议或契约）

A = MTBF / (MTBF+MTTR）

1.3 系统故障

硬件故障：设计缺陷、wear out（损耗）、非人为不可抗拒因素软件故障：设计缺陷 bug

1.4 实现高可用

提升系统高用性的解决方案：降低MTTR- Mean Time To Repair(平均故障时间)

解决方案：建立冗余机制

active/passive 主/备

active/active 双主 active --> HEARTBEAT --> passive active <--> HEARTBEAT <--> active

1.5.VRRP：Virtual Router Redundancy Protocol

虚拟路由冗余协议,解决静态网关单点风险

物理层:路由器、三层交换机

软件层:keepalived

1.5.1 VRRP 相关术语

虚拟路由器：Virtual Router

虚拟路由器标识：VRID(0-255)，唯一标识虚拟路由器

VIP：Virtual IP

VMAC：Virutal MAC (00-00-5e-00-01-VRID)

物理路由器： master：主设备

backup：备用设备

priority：优先级

1.5.2 VRRP 相关技术

通告：心跳，优先级等；

周期性工作方式：抢占式，非抢占式安全认证： 无认证

简单字符认证：预共享密钥

MD5 工作模式： 主/备：单虚拟路由器

主/主：主/备（虚拟路由器1），备/主（虚拟路由器2

二、keepalived部署

2.1 keepalived简介

vrrp 协议的软件实现，原生设计目的为了高可用 ipvs服务

官网：http://keepalived.org/

功能：

基于vrrp协议完成地址流动 为vip地址所在的节点生成ipvs规则(在配置文件中预先定义) 为ipvs集群的各RS做健康状态检测 基于脚本调用接口完成脚本中定义的功能，进而影响集群事务，以此支持nginx、haproxy等服务

2.2keepalived架构

官方文档：

https://keepalived.org/doc/

http://keepalived.org/documentation.html

用户空间核心组件：

vrrp stack：VIP消息通告

checkers：监测real server

system call：实现 vrrp 协议状态转换时调用脚本的功能

SMTP：邮件组件

IPVS wrapper：生成IPVS规则

Netlink Reflector：网络接口

WatchDog：监控进程

控制组件：提供keepalived.conf 的解析器，完成Keepalived配置

IO复用器：针对网络目的而优化的自己的线程抽象

内存管理组件：为某些通用的内存管理功能（例如分配，重新分配，发布等）提供访问权限

2.3 keepalived环境准备

各节点时间必须同步：ntp.chrony

关闭防火墙及SELinux

各节点之间可通过主机名互相通信：非必须

建议使用/etc/hosts文件实现：非必须

各节点之间的root用户可以基于密钥认证的ssh服务完成互相通信：feibixu

2..4 keepalived相关文件

软件包名：keepalived

主程序文件：/usr/sbin/keepalived/keepalived.conf

主配置文件：/etc/keepalived/keepalived.conf

配置文件示例：/usr/share/doc/keepalived/

Unit File： /lib/systemd/system/keepalived.service

Unit File的环境配置文件：/etc/sysconfig/keepalived

2.5 keepalived配置说明

2.6.1 配置文件组成部分

配置文件：/etc/keepalived/keepalived.conf

配置文件组成

GLOBAL CONFIGURATION

Global definitions： 定义邮件配置，route_id，vrrp配置，多播地址等

VRRP CONFIGURATION VRRP instance(s)： 定义每个vrrp虚拟路由器

LVS CONFIGURATION

Virtual server group(s)

Virtual server(s)： LVS集群的VS和RS

三、实战

1.Keepalived实验环境设定

1.环境设定图

2.环境设定

#部署rs1和rh2（单网卡NAT模式）
[root@rs1 ~]# vmset.sh eth0 172.25.254.10 rs1
[root@rs1 ~]# dnf install httpd -y
[root@rs1 ~]# echo RS1 - 172.25.254.10 > /var/www/html/index.html
[root@rs1 ~]# systemctl enable --now httpd

[root@rs2 ~]# vmset.sh eth0 172.25.254.20 rs2
[root@rs2 ~]# dnf install httpd -y
[root@rs2 ~]# echo RS2 - 172.25.254.20 > /var/www/html/index.html
[root@rs2 ~]# systemctl enable --now httpd

#测试：

#设定ka1和ka2
[root@KA1 ~]# vmset.sh eth0 172.25.254.50 KA1
[root@KA2 ~]# vmset.sh eth0 172.25.254.60 KA6

#设定本地解析
[root@KA1 ~]# vim /etc/hosts
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
::1 localhost localhost.localdomain localhost6 localhost6.localdomain6
172.25.254.50 KA1
172.25.254.60 KA2
172.25.254.10 rs1
172.25.254.20 rs2

[root@KA1 ~]# for i in 60 10 20
> do
> scp /etc/hosts 172.25.254.$i:/etc/hosts
> done

#在所有主机中查看/etc/hosts

#在ka1中开启时间同步服务
[root@KA1 ~]# vim /etc/chrony.conf
26 allow 0.0.0.0/0
29 local stratum 10

[root@KA1 ~]# systemctl restart chronyd
[root@KA1 ~]# systemctl enable --now chronyd

#在ka2中使用ka1的时间同步服务
[root@KA2 ~]# vim /etc/chrony.conf
pool 172.25.254.50 iburst

[root@KA2 ~]# systemctl restart chronyd
[root@KA2 ~]# systemctl enable --now chronyd

[root@KA2 ~]# chronyc sources -v

2.Keepalived虚拟路由配置

1.Keepalived安装

[root@KA1 ~]# dnf install keepalived.x86_64 -y
[root@KA2 ~]# dnf install keepalived.x86_64 -y

2.配置虚拟路由

#在master
[root@KA1 ~]# vim /etc/keepalived/keepalived.conf
global_defs {
notification_email {
[e-mail]
}
notification_email_from [e-mail]
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id KA1
vrrp_skip_check_adv_addr
#vrrp_strict
vrrp_garp_interval 1
vrrp_gna_interval 1
vrrp_mcast_group4 224.0.0.44
}
vrrp_instance WEB_VIP {
state MASTER
interface eth0
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
172.25.254.100/24 dev eth0 label eth0:0
}
}

[root@KA1 ~]# systemctl enable --now keepalived.service
Created symlink /etc/systemd/system/multi-user.target.wants/keepalived.service → /usr/lib/systemd/system/keepalived.service.

#在KA2中设定
[root@KA2 ~]# vim /etc/keepalived/keepalived.conf
global_defs {
notification_email {
[e-mail]
}
notification_email_from [e-mail]
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id KA1
vrrp_skip_check_adv_addr
#vrrp_strict
vrrp_garp_interval 1
vrrp_gna_interval 1
vrrp_mcast_group4 224.0.0.44
}
vrrp_instance WEB_VIP {
state BACKUP
interface eth0
virtual_router_id 51
priority 80
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
172.25.254.100/24 dev eth0 label eth0:0
}
}

[root@KA2 ~]# systemctl enable --now keepalived.service

#验证
[root@KA1 ~]# tcpdump -i eth0 -nn host 224.0.0.44

[root@KA1 ~]# ifconfig

#测试故障
#在一个独立的shell中执行
[root@KA1 ~]# tcpdump -i eth0 -nn host 224.0.0.44

#在kA1中模拟故障
[root@KA1 ~]# systemctl stop keepalived.service

#在KA2中看vip是否被迁移到当前主机
[root@KA2 ~]# ifconfig

3.Keepalived日志分离

默认情况下。keepalived的日志会被保存在/var/log/messages文件中，这个文件中除了含有keepalived的日志外，还有其他服务的日志信息，这样不利于对于keepalived的日志进行查看

[root@KA1 ~]# vim /etc/sysconfig/keepalived
KEEPALIVED_OPTIONS="-D -S 6"
[root@KA1 ~]# systemctl restart keepalived.service

[root@KA1 ~]# vim /etc/rsyslog.conf
local6.* /var/log/keepalived.log
[root@KA1 ~]# systemctl restart rsyslog.service

#测试

4.Keepalived的子配置文件设定

在主配置文件中如果写入过多的配置不利于对于主配置文件的阅读

[root@KA1 ~]# vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived

global_defs {
notification_email {
[e-mail]
}
notification_email_from [e-mail]
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id KA1
vrrp_skip_check_adv_addr
#vrrp_strict
vrrp_garp_interval 1
vrrp_gna_interval 1
vrrp_mcast_group4 224.0.0.44
}

include /etc/keepalived/conf.d/*.conf #指定独立子配置文件

[root@KA1 ~]# mkdir /etc/keepalived/conf.d -p
[root@KA1 ~]# vim /etc/keepalived/conf.d/webvip.conf
vrrp_instance WEB_VIP {
state MASTER
interface eth0
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
172.25.254.100/24 dev eth0 label eth0:0
}
}

[root@KA1 ~]# keepalived -t -f /etc/keepalived/keepalived.conf
[root@KA1 ~]# systemctl restart keepalived.service
[root@KA1 ~]# ifconfig

5.抢占模式

1.抢占模式preempt_delay( 默认的，谁优先级高就把vip放到哪里)

抢占延迟模式，即优先级高的主机恢复后，不会立即抢回VIP，而是延迟一段时间（默认300s）再抢回

注意：需要各keepalived服务器state为BACKUP并且不要启用 vrrp strict

2.非抢占模式nopreempt（持有vip只要vrrp通告正常就不做vip迁移

默认为抢占模式preempt，即当高优先级的主机恢复在线后，会抢占低先级的主机的master角色，这样会使vip在KA主机中来回漂移，造成网络抖动，建议设置为非抢占模式 nopreempt ，即高优先级主机恢复后，并不会抢占低优先级主机的master角色非抢占模块下,如果原主机down机, VIP迁移至的新主机, 后续也发生down时,仍会将VIP迁移回原主机

注意：要关闭 VIP抢占，必须将各 keepalived 服务器state配置为BACKUP

#kA1中
[root@KA1 ~]# vim /etc/keepalived/keepalived.conf
vrrp_instance WEB_VIP {
state BACKUP #非抢占模式互为backup
interface eth0
virtual_router_id 51
nopreempt #启动非抢占模式
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
172.25.254.100/24 dev eth0 label eth0:0
}
}

[root@KA1 ~]# systemctl stop keepalived.service

#KA2中
[root@KA2 ~]# vim /etc/keepalived/keepalived.conf
vrrp_instance WEB_VIP {
state BACKUP
interface eth0
virtual_router_id 51
nopreempt #开启非抢占模式
priority 80
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
172.25.254.100/24 dev eth0 label eth0:0
}
}
[root@KA2 ~]# systemctl stop keepalived.service

#测试：
[root@KA1 ~]# systemctl start keepalived.service
[root@KA2 ~]# systemctl start keepalived.service

[root@KA1 ~]# systemctl stop keepalived.service

3.延迟抢占

#kA1中
[root@KA1 ~]# vim /etc/keepalived/keepalived.conf
vrrp_instance WEB_VIP {
state BACKUP #非抢占模式互为backup
interface eth0
virtual_router_id 51
preempt_delay 10 #启动延迟抢占，延迟10s抢占
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
172.25.254.100/24 dev eth0 label eth0:0
}
}

[root@KA1 ~]# systemctl stop keepalived.service

#KA2中
[root@KA2 ~]# vim /etc/keepalived/keepalived.conf
vrrp_instance WEB_VIP {
state BACKUP
interface eth0
virtual_router_id 51
preempt_delay 10 #启动延迟抢占，延迟10s抢占
priority 80
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
172.25.254.100/24 dev eth0 label eth0:0
}
}
[root@KA2 ~]# systemctl stop keepalived.service

#测试：

[root@KA1 ~]# systemctl start keepalived.service
[root@KA2 ~]# systemctl start keepalived.service

#在一个独立的shell中开启ip的监控
[root@KA1 ~]# watch -n 1 ifconfig

#在KA1另外的shell中关闭keepalived
[root@KA1 ~]# systemctl stop keepalived.service

[root@KA1 ~]# systemctl start keepalived.service
#操作完毕后观察监控中vip的迁移延迟过

4.keepalived单播模式

为什么要单播，组播模式使用的网址资源最少，但是不能跨网络，如果主备两台主机是跨网络的，那么只能启用单播来实现vrrp通告

#在KA1中
[root@KA1 ~]# vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived

global_defs {
notification_email {
[e-mail]
}
notification_email_from [e-mail]
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id KA1
vrrp_skip_check_adv_addr
#vrrp_strict
vrrp_garp_interval 1
vrrp_gna_interval 1
#vrrp_mcast_group4 224.0.0.44 #关闭组播
}

vrrp_instance WEB_VIP {
state MASTER
interface eth0
virtual_router_id 51
priority 100
advert_int 1
unicast_src_ip 172.25.254.50 #指定单播源地址，通常是本机IP
unicast_peer {
172.25.254.60 #指定单播接收地址
}
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
172.25.254.100/24 dev eth0 label eth0:0
}
}

#在KA2中
[root@KA2 ~]# vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived

global_defs {
notification_email {
[e-mail]
}
notification_email_from [e-mail]
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id KA1
vrrp_skip_check_adv_addr
#vrrp_strict
vrrp_garp_interval 1
vrrp_gna_interval 1
#vrrp_mcast_group4 224.0.0.44 #关闭组播
}

vrrp_instance WEB_VIP {
state MASTER
interface eth0
virtual_router_id 51
priority 100
advert_int 1
unicast_src_ip 172.25.254.60 #指定单播源地址，通常是本机IP
unicast_peer {
172.25.254.50 #指定单播接收地址
}
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
172.25.254.100/24 dev eth0 label eth0:0
}
}

[root@KA1 ~]# systemctl restart keepalived.service
[root@KA2 ~]# systemctl restart keepalived.service

#测试
#在KA1中开启独立shell监控播报信息
[root@KA1 ~]# tcpdump -i eth0 -nn src host 172.25.254.50 and dst 172.25.254.60

#在KA2中开启独立shell监控播报信息
[root@KA2 ~]# tcpdump -i eth0 -nn src host 172.25.254.60 and dst 172.25.254.50

#在KA1正常时
#ka2播报信息不显示通告内容

6.Keepalived业务vip迁移告警

当keepalived的状态变化时，可以自动触发脚本的执行，比如：发邮件通知用户 默认以用户keepalived_script身份执行脚本 如果此用户不存在，以root执行脚本可以用下面指令指定脚本执行用户的身份

1.邮件告警环境构建

#安装邮件软件
[root@KA1 ~]# dnf install s-nail postfix -y
[root@KA2 ~]# dnf install s-nail postfix -y

#启动邮件代理
[root@KA1 ~]# systemctl start postfix.service
[root@KA2 ~]# systemctl start postfix.service

#设定sendmail

#在Linux主机中配置mailrc（KA1+KA2）
[root@KA1+KA2 ~]# vim /etc/mail.rc
set smtp=smtp.163.com
set smtp-auth=login
set smtp-auth-user=[e-mail]
set smtp-auth-password=TGfdKaJT7EB
set from=[e-mail]
set ssl-verify=ignore

#测试邮件
[root@KA1 mail]# echo hello | mailx -s test [e-mail]

[root@KA1 mail]# mailq #查看邮件队列
Mail queue is empty

[root@KA1 mail]# mail #查看是否又退信

#查看对应邮箱是否有邮件收到

2.设定keepalived告警脚本

[root@KA1 ~]# mkdir -p /etc/keepalived/scripts
[root@KA2 ~]# mkdir -p /etc/keepalived/scripts

#编写告警脚本
[root@KA1+2 ~]# vim /etc/keepalived/scripts/waring.sh
#!/bin/bash
mail_dest='[e-mail]'

mail_send()
{
mail_subj="$HOSTNAME to be $1 vip 转移"
mail_mess="`date +%F\ %T`: vrrp 转移,$HOSTNAME 变为 $1"
echo "$mail_mess" | mail -s "$mail_subj" $mail_dest
}
case $1 in
master)
mail_send master
;;
backup)
mail_send backup
;;
fault)
mail_send fault
;;
*)
exit 1
;;
esac

[root@KA1+2 ~]# chmod +x /etc/keepalived/scripts/waring.sh

[root@KA1 ~]# /etc/keepalived/scripts/waring.sh master

#对应邮箱中会出现邮件

3.配置keepalived告警

#在KA1和KA2中设定配置文件
! Configuration File for keepalived

global_defs {
notification_email {
[e-mail]
}
notification_email_from [e-mail]
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id KA1
vrrp_skip_check_adv_addr
#vrrp_strict
vrrp_garp_interval 1
vrrp_gna_interval 1
vrrp_mcast_group4 224.0.0.44
enable_script_security
script_user root
}
vrrp_instance WEB_VIP {
state MASTER
interface eth0
virtual_router_id 51
priority 100
advert_int 1
# unicast_src_ip 172.25.254.50
# unicast_peer {
# 172.25.254.60
# }
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
172.25.254.100/24 dev eth0 label eth0:0
}
notify_master "/etc/keepalived/scripts/waring.sh master"
notify_backup "/etc/keepalived/scripts/waring.sh backup"
notify_fault "/etc/keepalived/scripts/waring.sh fault"
}

[root@KA1+2 ~]# systemctl restart keepalived.service

#测试
[root@KA1 ~]# systemctl stop keepalived.service #停止服务后查看邮件

[root@KA1 ~]# systemctl start keepalived.service #开启服务后查看邮件

7.Keepalived双主模式

master/slave的单主架构，同一时间只有一个Keepalived对外提供服务，此主机繁忙，而另一台主机却很空闲，利用率低下，可以使用master/master的双主架构，解决此问题。 master/master 的双主架构： 即将两个或以上VIP分别运行在不同的keepalived服务器，以实现服务器并行提供web访问的目的，提高服务器资源利用率

#在KA1中
[root@KA1 ~]# vim /etc/keepalived/keepalived.conf
vrrp_instance WEB_VIP { #第一个虚拟路由，以master身份设定
state MASTER
interface eth0
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
172.25.254.100/24 dev eth0 label eth0:0
}
}

vrrp_instance DB_VIP { #第二个虚拟路由。以backup身份设定
state BACKUP
interface eth0
virtual_router_id 52
priority 80
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
172.25.254.200/24 dev eth0 label eth0:1
}
}

#KA2中
[root@KA2 ~]# vim /etc/keepalived/keepalived.conf
vrrp_instance WEB_VIP {
state BACKUP
interface eth0
virtual_router_id 51
preempt_delay 10
priority 80
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
172.25.254.100/24 dev eth0 label eth0:0
}
}
vrrp_instance DB_VIP {
state MASTER
interface eth0
virtual_router_id 52
preempt_delay 10
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
172.25.254.200/24 dev eth0 label eth0:1
}
}
[root@KA1 ~]# systemctl restart keepalived.service
[root@KA2 ~]# systemctl restart keepalived.service

#测试
[root@KA1 ~]# ifconfig

[root@KA1 ~]# systemctl stop keepalived.service
[root@KA2 ~]# ifconfig

[root@KA2 ~]# systemctl stop keepalived.service
[root@KA1 ~]# ifconfig

8.实现IPVS的高可用性

1.配置RS

[root@rs1+2 ~]# cd /etc/NetworkManager/system-connections/
[root@rs1+2 system-connections]# ls
eth0.nmconnection
[root@rs1+2 system-connections]# cp eth0.nmconnection lo.nmconnection -p
[root@rs1+2 system-connections]# vim lo.nmconnection

[connection]
id=lo
type=loopback
interface-name=lo

[ipv4]
method=manual
address1=127.0.0.1/8
address2=172.25.254.100/32

[root@rs1+2 system-connections]# nmcli connection reload
[root@rs1+2 system-connections]# nmcli connection up lo
[root@rs1+2 system-connections]# ip a

[root@rs1+2 system-connections]# vim /etc/sysctl.conf
net.ipv4.conf.all.arp_ignore=1
net.ipv4.conf.all.arp_announce=2
net.ipv4.conf.lo.arp_announce=2
net.ipv4.conf.lo.arp_ignore=1

[root@rs1+2 system-connections]# sysctl -p
net.ipv4.conf.all.arp_ignore = 1
net.ipv4.conf.all.arp_announce = 2
net.ipv4.conf.lo.arp_announce = 2
net.ipv4.conf.lo.arp_ignore = 1

#安装ipvsadm
[root@KA1+KA2 ~]# dnf install ipvsadm -y

2.实现方式

#在keepalived的所有主机中
[root@KA1 ~]# vim /etc/keepalived/keepalived.conf
virtual_server 172.25.254.100 80 {
delay_loop 6
lb_algo rr
lb_kind DR
protocol TCP

real_server 172.25.254.10 80 {
weight 1
HTTP_GET {
url {
path /
status_code 200
}
connect_timeout 1
retry 3
delay_before_retry 1
}
}

real_server 172.25.254.20 80 {
weight 1
TCP_CHECK {
connect_timeout 5
retry 3
delay_before_retry 3
connect_port 80
}
}
}

[root@KA1 ~]# systemctl restart keepalived.service

3.测试

#友情提示：不要再KA1和KA2中访问vip，会检测不出效果

#在ka1中开启独立的shell
[root@KA1 ~]# watch -n 1 ipvsadm -Ln

#在RS1中关闭wen服务查看lvs策略是否变化

#把ka1中的keepalived关闭查看ka2中是否自动生成lvs策略

9.双主模式代理不同业务实现高可用

1.实验环境

#web服务设定再个实验已经设定完成
#在rs中设定lo添加vip2 172.25.254.200、32
#在rs中搭建数据库

#web服务设定再个实验已经设定完成
#在rs中设定lo添加vip2 172.25.254.200、32
#在rs中搭建数据库
[root@rs1+2 ~]# dnf install mariadb-server -y
[root@rs1+2 ~]# systemctl enable --now mariadb
[root@rs1+2 ~]# mysql
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MariaDB connection id is 3
Server version: 10.5.27-MariaDB MariaDB Server

Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

MariaDB [(none)]> CREATE USER lee@'%' identified by 'lee';
Query OK, 0 rows affected (0.001 sec)

MariaDB [(none)]> GRANT ALL ON *.* TO lee@'%';
Query OK, 0 rows affected (0.001 sec)

#测试

2.实现不同vip代理不同业务

#KA1和KA2
[root@KA1+2 ~]# vim /etc/keepalived/keepalived.conf
include /etc/keepalived/conf.d/webserver.conf
include /etc/keepalived/conf.d/datebase.conf

[root@KA1+2 ~]# vim /etc/keepalived/conf.d/webserver.conf
virtual_server 172.25.254.100 80 {
delay_loop 6
lb_algo rr
lb_kind DR
protocol TCP

real_server 172.25.254.10 80 {
weight 1
HTTP_GET {
url {
path /
status_code 200
}
connect_timeout 1
retry 3
delay_before_retry 1
}
}

real_server 172.25.254.20 80 {
weight 1
TCP_CHECK {
connect_timeout 5
retry 3
delay_before_retry 3
connect_port 80
}
}
}
[root@KA1 ~]# vim /etc/keepalived/conf.d/datebase.conf
virtual_server 172.25.254.200 3306 {
delay_loop 6
lb_algo rr
lb_kind DR
protocol TCP

real_server 172.25.254.10 3306 {
weight 1
TCP_CHECK {
connect_timeout 5
retry 3
delay_before_retry 3
connect_port 3306
}
}

real_server 172.25.254.20 3306 {
weight 1
TCP_CHECK {
connect_timeout 5
retry 3
delay_before_retry 3
connect_port 3306
}
}
}

[root@KA1+2 ~]# systemctl restart keepalived.service

3.测试

10.利用VRRP Script 实现全能高可用

keepalived利用 VRRP Script 技术，可以调用外部的辅助脚本进行资源监控，并根据监控的结果实现优先动态调整，从而实现其它应用的高可用性功能

参考配置文件：/usr/share/doc/keepalived/keepalived.conf.vrrp.localcheck

VRRP Script配置

分两步实现：

定义脚本 vrrp_script：自定义资源监控脚本，vrrp实例根据脚本返回值，公共定义，可被多个实例调用，定 义在vrrp实例之外的独立配置块，一般放在global_defs设置块之后。 通常此脚本用于监控指定应用的状态。一旦发现应用的状态异常，则触发对MASTER节点的权重减至 低于SLAVE节点，从而实现 VIP 切换到 SLAVE 节点

调用脚本

track_script：调用vrrp_script定义的脚本去监控资源，定义在VRRP实例之内，调用事先定义的vrrp_script

1.实验环境

#在KA1和KA2中安装haproxy
[root@KA1+2 ~]# dnf install haproxy-2.4.22-4.el9.x86_64 -y
[root@KA1 ~]# vim /etc/sysctl.conf

[root@KA1+2 ~]# vim /etc/sysctl.conf
net.ipv4.ip_nonlocal_bind=1

[root@KA1+2 ~]# vim /etc/haproxy/haproxy.cfg
listen webserver
bind 172.25.254.100:80
mode http
server web1 172.25.254.10:80 check
server web2 172.25.254.20:80 check

[root@KA1+2 ~]# systemctl enable --now haproxy.service

2.利用案例理解vrrp_scripts

#在KA1主机中
[root@KA1 ~]# vim /etc/keepalived/scripts/test.sh
#!/bin/bash
[ ! -f "/mnt/lee" ]

[root@KA1 ~]# vim /etc/keepalived/keepalived.conf
vrrp_script check_lee {
script "/etc/keepalived/scripts/test.sh"
interval 1
weight -30
fall 2
rise 2
timeout 2
user root
}
vrrp_instance DB_VIP {
state MASTER
interface eth0
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
172.25.254.100/24 dev eth0 label eth0:1
}
track_script {
check_lee
}
}

[root@KA1 ~]# systemctl restart keepalived.service

#测试：
[root@KA1 ~]# ifconfig

[root@KA1 ~]# touch /mnt/lee

[root@KA1 ~]# rm -fr /mnt/lee

3.keepalived + haproxy

[root@KA1 ~]# vim /etc/keepalived/scripts/haproxy_check.sh
#!/bin/bash
killall -0 haproxy &> /dev/null

[root@KA1 ~]# chmod +x /etc/keepalived/scripts/haproxy_check.sh
vrrp_script haporxy_check {
script "/etc/keepalived/scripts/haproxy_check.sh"
interval 1
weight -30
fall 2
rise 2
timeout 2
user root
}
vrrp_instance WEB_VIP {
state MASTER
interface eth0
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
172.25.254.100/24 dev eth0 label eth0:0
}
track_script {
haporxy_check
}
}

[root@KA1 ~]# systemctl restart keepalived.service

#测试
通过关闭和开启haproxy来观察vip是否迁移