高可用集群keepalived(知识点+实验)详细版

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筋斗云
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高可用集群KEEPALIVED

.高可用集群

1.1 集群类型

  • LBLoad Balance 负载均衡

      LVS/HAProxy/nginxhttp/upstream, stream/upstream

  • HAHigh Availability 高可用集群

     数据库、Redis

  • SPoF: Single Point of Failure,解决单点故障

     HPCHigh Performance Computing 高性能集群

1.2 系统可用性

SLAService-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+MTTR99.95%:(60*24*30)*(1-0.9995)=21.6分钟 #一般按一个月停机时间统计指标 :99.9%, 99.99%, 99.999%,99.9999%

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

1.5.VRRPVirtual 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

  1. 虚拟路由器:Virtual Router
  2. 虚拟路由器标识:VRID(0-255),唯一标识虚拟路由器
  3. VIPVirtual IP
  4. VMACVirutal MAC (00-00-5e-00-01-VRID)
  5. 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:
  • /备:单虚拟路由器
  • /主:主/备(虚拟路由器1),备/主(虚拟路由器2

1.6Keepalived 相关文件

  • 软件包名:keepalived
  • 主程序文件:/usr/sbin/keepalived
  • 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
Warning RHEL7中可能会遇到一下bug systemctl restart keepalived #新配置可能无法生效 systemctl stop keepalived;systemctl start keepalived #无法停止进程,需要 kill

二、 全局配置

! Configuration File for keepalived global_defs {     notification_email {            594233887@qq.com#keepalived 发生故障切换时邮件发送的目标邮箱,可以按行区分写多个                 timiniglee-zln@163.com } notification_email_from keepalived@KA1.timinglee.org      #发邮件的地址 smtp_server 127.0.0.1                                                        #邮件服务器地址 smtp_connect_timeout 30                                                   #邮件服务器连接timeout router_id KA1.timinglee.org                                         #每个keepalived主机唯一标识                                                                     #建议使用当前主机名,但多节点重名不影响 vrrp_skip_check_adv_addr                              #对所有通告报文都检查,会比较消耗性能 #启用此配置后,如果收到的通告报文和上一个报文是同一 #个路由器,则跳过检查,默认 值为全检查 vrrp_strict                                                                             #严格遵循vrrp协议                                                                            #启用此项后以下状况将无法启动服务:                                                                                                                                    #1.VIP地址                                                                                             #2.配置了单播邻居                                                                                          #3.VRRP版本2中有IPv6地址                                                                                             #建议不加此项配置 vrrp_garp_interval 0                                                 #报文发送延迟,0表示不延迟 vrrp_gna_interval 0                                                                 #消息发送延迟 vrrp_mcast_group4 224.0.0.18                                          #指定组播IP地址范围: }

三、配置虚拟路由器

vrrp_instance VI_1 {              state MASTER        interface eth0 #绑定为当前虚拟路由器使用的物理接口,如:eth0,可以和VIP不在一个网卡       virtual_router_id 51    #每个虚拟路由器惟一标识,范围:0-255,每个虚拟路由器此值必须唯一                               #否则服务无法启动                               #同属一个虚拟路由器的多个keepalived节点必须相同                                #务必要确认在同一网络中此值必须唯一         priority 100           #当前物理节点在此虚拟路由器的优先级,范围:1-254                                #值越大优先级越高,每个keepalived主机节点此值不同        advert_int 1           #vrrp通告的时间间隔,默认1s        authentication {       #认证机制             auth_type AH|PASS     #AH为IPSEC认证(不推荐),PASS为简单密码(建议使用)             uth_pass 1111        #预共享密钥,仅前8位有效                                  #同一个虚拟路由器的多个keepalived节点必须一样       }      virtual_ipaddress {        #虚拟IP,生产环境可能指定上百个IP地址      <IPADDR>/<MASK> brd <IPADDR> dev <STRING> scope <SCOPE> label <LABEL>           172.25.254.100     #指定VIP,不指定网卡,默认为eth0,注意:不指定/prefix,默认32       172.25.254.101/24 dev eth1       172.25.254.102/24 dev eth2 label eth2:1       }  }  

四、抢占模式和非抢占模式

1、非抢占模式 nopreempt

        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, VIP迁移至的新主机, 后续也发生down,仍会将VIP迁移回原主机
Note 注意:要关闭 VIP抢占,必须将各 keepalived 服务器state配置为BACKUP

2、抢占延迟模式 preempt_delay

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 VIP
preempt_delay # #指定抢占延迟时间为#s,默认延迟300s
Note 注意:需要各keepalived服务器state为BACKUP,并且不要启用 vrrp_strict

五、VIP单播配置

       默认keepalived主机之间利用多播相互通告消息,会造成网络拥塞,可以替换成单播,减少网络流量
[!NOTE] 注意:启用 vrrp_strict 时,不能启用单播
#在所有节点vrrp_instance语句块中设置对方主机的IP,建议设置为专用于对应心跳线网络的地址,而非使用业务网络
unicast_src_ip <IPADDR> #指定发送单播的源IP unicast_peer { <IPADDR> #指定接收单播的对方目标主机IP ...... }

六、Keepalived 通知脚本配置

1、通知脚本类型

当前节点成为主节点时触发的脚本  notify_master <STRING>|<QUOTED-STRING>  当前节点转为备节点时触发的脚本  notify_backup <STRING>|<QUOTED-STRING>  当前节点转为“失败”状态时触发的脚本  notify_fault <STRING>|<QUOTED-STRING>  通用格式的通知触发机制,一个脚本可完成以上三种状态的转换时的通知  notify <STRING>|<QUOTED-STRING>  当停止VRRP时触发的脚本  notify_stop <STRING>|<QUOTED-STRING>

2、脚本的调用方法

vrrp_instance VI_1 语句块的末尾加下面行 notify_master "/etc/keepalived/notify.sh master" notify_backup "/etc/keepalived/notify.sh backup" notify_fault "/etc/keepalived/notify.sh fault"

七:双主架构

实现 master/master Keepalived 双主架构 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

八、实现IPVS的高可用性

1、IPVS相关配置

1.1虚拟服务器配置结构

virtual_server IP port { ... real_server { ... } real_server { ... } }

1.2 virtual server (虚拟服务器)的定义格式

virtual_server IP port #定义虚拟主机IP地址及其端口 virtual_server fwmark int #ipvs的防火墙打标,实现基于防火墙的负载均衡集群 virtual_server group string #使用虚拟服务器组

1.3 虚拟服务器配置

virtual_server IP port { #VIPPORT delay_loop <INT> #检查后端服务器的时间间隔 lb_algo rr|wrr|lc|wlc|lblc|sh|dh #定义调度方法 lb_kind NAT|DR|TUN #集群的类型,注意要大写 persistence_timeout <INT> #持久连接时长 protocol TCP|UDP|SCTP #指定服务协议,一般为TCP sorry_server <IPADDR> <PORT> #所有RS故障时,备用服务器地址 real_server <IPADDR> <PORT> { #RSIPPORT weight <INT> #RS权重 notify_up <STRING>|<QUOTED-STRING> #RS上线通知脚本 notify_down <STRING>|<QUOTED-STRING> #RS下线通知脚本 HTTP_GET|SSL_GET|TCP_CHECK|SMTP_CHECK|MISC_CHECK { ... } #定义当前主机健康状 态检测方法    } } #注意:括号必须分行写,两个括号写在同一行,: }} 会出错

1.4 应用层监测

应用层检测:HTTP_GET|SSL_GET
HTTP_GET|SSL_GET { url { path <URL_PATH> #定义要监控的URL status_code <INT> #判断上述检测机制为健康状态的响应码,一般为 200 } connect_timeout <INTEGER> #客户端请求的超时时长, 相当于haproxytimeout server nb_get_retry <INT> #重试次数 delay_before_retry <INT> #重试之前的延迟时长 connect_ip <IP ADDRESS> #向当前RS哪个IP地址发起健康状态检测请求 connect_port <PORT> #向当前RS的哪个PORT发起健康状态检测请求 bindto <IP ADDRESS> #向当前RS发出健康状态检测请求时使用的源地址 bind_port <PORT> #向当前RS发出健康状态检测请求时使用的源端口 }

1.5 TCP监测

传输层检测:TCP_CHECK
TCP_CHECK { connect_ip <IP ADDRESS> #向当前RS的哪个IP地址发起健康状态检测请求 connect_port <PORT> #向当前RS的哪个PORT发起健康状态检测请求 bindto <IP ADDRESS> #发出健康状态检测请求时使用的源地址 bind_port <PORT> #发出健康状态检测请求时使用的源端口 connect_timeout <INTEGER> #客户端请求的超时时长 #等于haproxytimeout server }

九、实现其它应用的高可用性 VRRP Script

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

1、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
vrrp_script <SCRIPT_NAME> { script <STRING>|<QUOTED-STRING> #此脚本返回值为非0时,会触发下面OPTIONS执行 OPTIONS }
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
track_script {   SCRIPT_NAME_1   SCRIPT_NAME_2 }

2、定义 VRRP script

vrrp_script <SCRIPT_NAME> { #定义一个检测脚本,在global_defs 之外配置 script <STRING>|<QUOTED-STRING> #shell命令或脚本路径 interval <INTEGER> #间隔时间,单位为秒,默认1timeout <INTEGER> #超时时间 weight <INTEGER:-254..254> #默认为0,如果设置此值为负数, #当上面脚本返回值为非0#会将此值与本节点权重相加可以降低本节点权重, #即表示fall. #如果是正数,当脚本返回值为0#会将此值与本节点权重相加可以提高本节点权重 #即表示 rise.通常使用负值 fall <INTEGER> #执行脚本连续几次都失败,则转换为失败,建议设为2以上 rise <INTEGER> #执行脚本连续几次都成功,把服务器从失败标记为成功 user USERNAME [GROUPNAME] #执行监测脚本的用户或组 init_fail #设置默认标记为失败状态,监测成功之后再转换为成功状态 }

3、调用 VRRP script

vrrp_instance test { ... ... track_script {     check_down    } }

keepalived实验

一、虚拟路由管理

1、ip配置

[root@ka1 ~]# vmset.sh eth0 172.25.254.10 ka1.hyl.oeg
[root@ka1 ~]# systemctlstop firewalld.service

[root@ka2 ~]# # vmset.sh eth0 172.25.254.20 ka2.hyl.oeg
[root@ka2 ~]# systemctlstop firewalld.service

[root@realserver1 ~]# vmset.sh eth0 172.25.254.110 realserver1.hyl.oeg
[root@realserver1 ~]#systemctlstop firewalld.service

[root@realserver2 ~]#vmset.sh eth0 172.25.254.120 realserver2.hyl.oeg
[root@realserver2~]#systemctlstop firewalld.service

2、配置httpd

[root@realserver1~]# yum install httpd -y

[root@realserver1 ~]# echo 172.25.254.110 > /var/www/html/index.html

[root@realserver1 ~]# systemctl enable --now httpd

Created symlink from /etc/systemd/system/multi-user.target.wants/httpd.service to /usr/lib/systemd/system/httpd.service.

[root@realserver2 ~]# yum install httpd -y

[root@realserver2 ~]# echo 172.25.254.120 > /var/www/html/index.html

[root@realserver2 ~]# systemctl enable --now httpd

Created symlink from /etc/systemd/system/multi-user.target.wants/httpd.service to /usr/lib/systemd/system/httpd.service.

测试

[root@ka1 ~]# curl 172.25.254.110 172.25.254.110

[root@ka1 ~]# curl 172.25.254.120 172.25.254.120

3、安装 keepalived

[root@ka1 ~]# yum install keepalived -y

[root@ka1 ~]# man keepalived.conf  帮助

4、全局配置

配置ka1端

[root@ka1 ~]# vim /etc/keepalived/keepalived.conf

重启服务

[root@ka1 ~]# systemctl enable --now keepalived

Created symlink from /etc/systemd/system/multi-user.target.wants/keepalived.service to /usr/lib/systemd/system/keepalived.service.

[root@ka1 ~]# systemctl restart keepalived

查看vip

安装tcpump

[root@ka1~]# yum install tcpdump -y

日志测试

[root@ka1 ~]# tcpdump -i eth0 -nn host 224.0.0.18

tcpdump: verbose output suppressed, use -v or -vv for full protocol decode

listening on eth0, link-type EN10MB (Ethernet), capture size 262144 bytes

11:05:37.766822 IP 172.25.254.10 > 224.0.0.18: VRRPv2, Advertisement, vrid 100, prio 100, authtype simple,

intvl 1s, length 20

11:05:38.768163 IP 172.25.254.10 > 224.0.0.18: VRRPv2, Advertisement, vrid 100, prio 100, authtype simple,

intvl 1s, length 20

11:05:39.769328 IP 172.25.254.10 > 224.0.0.18: VRRPv2, Advertisement, vrid 100, prio 100, authtype simple,

intvl 1s, length 20

ka2配置

[root@ka1 ~]# scp /etc/keepalived/keepalived.conf

root@172.25.254.20:/etc/keepalived/keepalived.conf

[root@ka2 ~]# vim /etc/keepalived/keepalived.conf

重启服务

[root@ka2 ~]# systemctl enable --now keepalived.service

Created symlink from /etc/systemd/system/multi-user.target.wants/keepalived.service to /usr/lib/systemd/system/keepalived.service.

[root@ka2 ~]# systemctl restart keepalived.service

[root@ka2 ~]# yum install tcpdump -y

查看ip

二、开启通信

[root@ka1 ~]# vim /etc/keepalived/keepalived.conf

 或者

[root@ka1 ~]# systemctl restart keepalived

[root@ka2 ~]# vim /etc/keepalived/keepalived.conf

[root@ka2 ~]# systemctl restart keepalived.service

测试

[root@ka2 ~]# ping 172.25.254.100

PING 172.25.254.100 (172.25.254.100) 56(84) bytes of data.

64 bytes from 172.25.254.100: icmp_seq=1 ttl=64 time=0.206 ms

64 bytes from 172.25.254.100: icmp_seq=2 ttl=64 time=0.441 ms

--- 172.25.254.100 ping statistics ---

2 packets transmitted, 2 received, 0% packet loss, time 999ms

rtt min/avg/max/mdev = 0.206/0.323/0.441/0.118 ms

三、开启独立日志功能

修改sysconfig文件

[root@ka1 ~]# vim /etc/sysconfig/keepalived

修改rsyslog文件

[root@ka1 ~]# vim /etc/rsyslog.conf

重启服务

[root@ka1 ~]# systemctl restart keepalived.service

[root@ka1 ~]# systemctl restart rsyslog.service

查看日志文件

[root@ka1 ~]# ll /var/log/keepalived.log

-rw------- 1 root root 2253 8月 12 11:56 /var/log/keepalived.log

四、实现独立子配置文件

注释文件内容

[root@ka1 ~]# vim /etc/keepalived/keepalived.conf

建立文件

[root@ka1 ~]# mkdir -p /etc/keepalived/conf.d

开启子文件

[root@ka1 ~]# vim /etc/keepalived/conf.d/172.25.254.100.conf

[root@ka1 ~]# systemctl restart keepalived.service

五、非抢占模式nopreempt

非抢占模式

[root@ka1 ~]# vim /etc/keepalived/keepalived.conf

[root@ka1 ~]# systemctl restart keepalived.service

[root@ka2 ~]# vim /etc/keepalived/keepalived.conf

[root@ka2~]# systemctl restart keepalived.service

测试

六、抢占延迟模式preempt_delay

[root@ka1 ~]# vim /etc/keepalived/keepalived.conf

[root@ka1 ~]# systemctl restart keepalived

[root@ka2 ~]# vim /etc/keepalived/keepalived.conf

[root@ka2 ~]# systemctl restart keepalived.service

七、组播变单播

主机配置

[root@ka1 ~]# vim /etc/keepalived/keepalived.conf

[root@ka1 ~]# systemctl restart keepalived

[root@ka2 ~]# vim /etc/keepalived/keepalived.conf

[root@ka2 ~]# systemctl restart keepalived.service

测试

[root@ka1 ~]# tcpdump -i eth0 -nn src host 172.25.254.10 and dst 172.25.254.20

tcpdump: verbose output suppressed, use -v or -vv for full protocol decode

listening on eth0, link-type EN10MB (Ethernet), capture size 262144 bytes 

14:57:34.119048 IP 172.25.254.10 > 172.25.254.20: VRRPv2, Advertisement, vrid 100, prio 100, authtype simple, intvl 1s, length 20

14:57:35.120354 IP 172.25.254.10 > 172.25.254.20: VRRPv2, Advertisement, vrid 100, prio 100, authtype simple, intvl 1s, length 20

14:57:35.127617 ARP, Reply 172.25.254.10 is-at 00:0c:29:5c:43:47, length 28

14:57:36.122126 IP 172.25.254.10 > 172.25.254.20: VRRPv2, Advertisement, vrid 100, prio 100, authtype simple, intvl 1s, length 20

^C

4 packets captured

4 packets received by filter

0 packets dropped by kernel

[root@ka1 ~]# systemctl stop keepalived

[root@ka2 ~]# tcpdump -i eth0 -nn src host 172.25.254.20 and dst 172.25.254.10

tcpdump: verbose output suppressed, use -v or -vv for full protocol decode

listening on eth0, link-type EN10MB (Ethernet), capture size 262144 bytes 15:00:16.652507 IP 172.25.254.20 > 172.25.254.10: VRRPv2, Advertisement, vrid 100, prio 80, authtype simple, intvl 1s, length 20

15:00:17.653821 IP 172.25.254.20 > 172.25.254.10: VRRPv2, Advertisement, vrid 100, prio 80, authtype simple, intvl 1s, length 20

15:00:18.655321 IP 172.25.254.20 > 172.25.254.10: VRRPv2, Advertisement, vrid 100, prio 80, authtype simple, intvl 1s, length 20

^C

3 packets captured

3 packets received by filter

0 packets dropped by kernel

八、邮件通知

安装邮件发送工具

[root@ka1 ~]# yum install mailx -y

[root@ka2 ~]# yum install mailx -y

QQ邮箱配置

[root@ka1 ~]# vim /etc/mail.rc

发送文件

[root@ka1 ~]# echo test message | mail -s test 3238886180@qq.com

实现 Keepalived 状态切换的通知脚本

编写脚本+权限

[root@ka1 ~]# vim /etc/keepalived/mail.sh

[root@ka1 ~]# chmod +x /etc/keepalived/mail.sh

[root@ka1 ~]# vim /etc/keepalived/keepalived.conf

[root@ka1 ~]# systemctl restart keepalived

测试

[root@ka1 ~]# /etc/keepalived/mail.sh master

[root@ka1 ~]# /etc/keepalived/mail.sh backup

[root@ka2 ~]# /etc/keepalived/mail.sh backup

[root@ka2 ~]# /etc/keepalived/mail.sh fault

[root@ka1 ~]# systemctl stop keepalived

[root@ka1 ~]# systemctl restart keepalived

九:双主架构

配置ka1、ka2文件

[root@ka1 ~]# vim /etc/keepalived/keepalived.conf

[root@ka1 ~]# systemctl restart keepalived

[root@ka2 ~]# vim /etc/keepalived/keepalived.conf

[root@ka2 ~]# systemctl restart keepalived

测试

十:keepalived+lvs

设定vip

[root@realserver1 ~]# ip a a 172.25.254.100/32 dev lo

[root@realserver1 ~]# vi /etc/sysctl.d/arp.conf

[root@realserver1 ~]# scp /etc/sysctl.d/arp.conf root@172.25.254.120:/etc/sysctl.d/arp.conf

ka1、ka2文件配置

[root@ka1 ~]# yum install ipvsadm -y

[root@ka1 ~]# vim /etc/keepalived/keepalived.conf

[root@ka1 ~]# systemctl restart keepalived

[root@ka2 ~]# yum install ipvsadm -y

[root@ka2 ~]# vim /etc/keepalived/keepalived.conf

[root@ka2 ~]# systemctl restart keepalived

测试

十一:利用脚本实现主从角色切换

[root@ka1 ~]# vim /etc/keepalived/test.sh

[root@ka1 ~]# chmod +x /etc/keepalived/test.sh

[root@ka1 ~]# cat /etc/keepalived/test.sh

#!/bin/bash

[ ! -f /mnt/lee ]

[root@ka1 ~]# vim /etc/keepalived/keepalived.conf

[root@ka1 ~]# systemctl restart keepalived

[root@ka1 ~]# sh /etc/keepalived/test.sh

[root@ka1 ~]# echo $?

0

[root@ka1 ~]# rm -rf /mnt/lee

[root@ka1 ~]# sh /etc/keepalived/test.sh

[root@ka1 ~]# echo $?

1

十二:实现HAProxy高可用

在两个ka1ka2两个节点启用内核参数

[root@ka1 ~]# vim /etc/sysctl.conf

net.ipv4.ip_nonlocal_bind = 1

[root@ka1 ~]# sysctl -p

net.ipv4.ip_nonlocal_bind = 1

[root@ka2 ~]# vim /etc/sysctl.conf

[root@ka2 ~]# sysctl -p

net.ipv4.ip_nonlocal_bind = 1

实现haproxy的配置 ka1、ka2

[root@ka1 ~]# yum install haproxy -y

[root@ka2 ~]# yum install haproxy -y

[root@ka1 ~]# vim /etc/haproxy/haproxy.cfg

[root@ka1 ~]# systemctl restart haproxy

[root@ka1 ~]# systemctl enable --now haproxy

Created symlink from /etc/systemd/system/multi-user.target.wants/haproxy.service to /usr/lib/sy stemd/system/haproxy.service.

server配置

[root@realserver1 ~]# ip a d 172.25.254.100/32 dev lo

[root@realserver2 ~]# ip a d 172.25.254.100/32 dev lo

[root@realserver1 ~]# vim /etc/sysctl.d/arp.conf

[root@realserver2 ~]# vim /etc/sysctl.d/arp.conf

测试

[root@realserver1 ~]# curl 172.25.254.110

172.25.254.110

[root@realserver1 ~]# curl 172.25.254.120

172.25.254.120

keepalived配置

[root@ka2 ~]# vim /etc/keepalived/keepalived.conf

注释掉lvs

[root@ka2 ~]# systemctl restart keepalived

查看服务

访问测试

为解决ka1的vip掉了 访问失败

[root@ka1 ~]# systemctl stop haproxy

[root@ka1 ~]# systemctl restart haproxy

[root@ka1 ~]# killall -0 haproxy

[root@ka1 ~]# systemctl stop haproxy

[root@ka1 ~]# killall -0 haproxy

haproxy: no process found

[root@ka1 ~]# [root@ka1 ~]# echo $?

1

[root@ka2 ~]# killall -0 haproxy

-bash: killall: 未找到命令

[root@ka2 ~]# yum install psmisc -y

[root@ka2 ~]# killall -0 haproxy

[root@ka2 ~]# echo $?

0

ka1中编写检测脚本

[root@ka1 ~]# mkdir /etc/keepalived/scripts

[root@ka1 ~]# vim /etc/keepalived/scripts/haproxy.sh

[root@ka1 ~]# chmod +x /etc/keepalived/scripts/haproxy.sh

ka1、2中配置keepalived

[root@ka1 ~]# vim /etc/keepalived/keepalived.conf

[root@ka1 ~]# systemctl restart keepalived

[root@ka2 ~]# vim /etc/keepalived/keepalived.conf

[root@ka2 ~]# systemctl restart keepalived

测试

进入循环测试
当关闭服务,则访问失败

[root@ka1 ~]# systemctl stop haproxy

当服务开启,继续循环访问

[root@ka1 ~]# systemctl start haproxy

可以发现vip重新回到ka1

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