4个节点：
keepalived1:
IP:172.16.20.10
hostname:knode1.lushenle.com
OS:CentOS Linux release 7.1.1503 (Core)
NetworkDEVICE:eno16777728
keepalived2:
IP:172.16.20.12
hostname:knode2.lushenle.com
OS:CentOS Linux release 7.1.1503 (Core)
NetworkDEVICE:eno16777728
Real Server1:
IP:172.16.100.40
hostname:node1.lushenle.com
OS:CentOS Linux release 7.4.1708 (Core)
NetworkDEVICE:ens32
Real Server2:
IP:172.16.100.50
hostname:node3.lushenle.com
OS:CentOS Linux release 7.4.1708 (Core)
NetworkDEVICE:ens32
还有一个节点是客户端，IP地址为172.16.100.20，OS为MacOSX。其中Real Server2还是yum源。VIP为172.16.20.100，各节点之间的都能相互解析主机名，使用了公钥认证
两个keepalived节点开启核心转发功能，操作是在keepalived1节点中完成的：
# echo 1 > /proc/sys/net/ipv4/ip_forward; ssh knode2.lushenle.com 'echo 1 > /proc/sys/net/ipv4/ip_forward'
安装keepalived，ipvsadm，httpd，其中httpd的作用是Sorry_server:
# yum install -y keepalived，ipvsadm，httpd; ssh knode2.lushenle.com 'yum install -y keepalived，ipvsadm，httpd'
# echo "<h1>The system is upgrading on knode1 Please wait a few minutes retry!<h1>" > /var/www/html/index.html
keepalived2也是一样的，但为了测试效果，加以区别，可显示不同的内容
# echo "<h1>The system is upgrading on knode2 Please wait a few minutes retry!<h1>" > /var/www/html/index.html
# systemctl start http; ssh knode2.lushenle.com 'systemctl start http'
配置keepalived，在不停止服务的前提下可以通过脚本的方式进行流转，且流转的时候发邮件：
# cp /etc/keepalived/keepalived.conf{,.bak} ```先备份一下```
# vim /etc/keepalived/keepalived.conf
1 ! Configuration File for keepalived 2 3 global_defs { 4 notification_email { 5 root@localhost 6 } 7 notification_email_from kaadmin@localhost 8 smtp_server 127.0.0.1 9 smtp_connect_timeout 30 10 router_id LVS_DEVEL 11 vrrp_mcast_group4 224.0.1.118 12 } 13 14 vrrp_script chk_down { 15 script "[[ -f /etc/keepalived/down ]] && exit 1 || exit 0" 16 interval 1 17 weight -20 18 } 19 20 vrrp_instance VI_1 { 21 state MASTER 22 interface eno16777728 23 virtual_router_id 144 24 priority 100 25 advert_int 1 26 authentication { 27 auth_type PASS 28 auth_pass 44dace615cdd5d26 29 } 30 virtual_ipaddress { 31 172.16.20.100/16 dev eno16777728 label eno16777728:1 32 } 33 34 track_script { 35 chk_down 36 } 37 38 notify_master "/etc/keepalived/notify.sh master" 39 notify_backup "/etc/keepalived/notify.sh backup" 40 notify_fault "/etc/keepalived/notify.sh fault" 41 } 42 43 virtual_server 172.16.20.100 80 { 44 delay_loop 6 45 lb_algo wrr 46 lb_kind DR 47 nat_mask 255.255.0.0 48 protocol TCP 49 sorry_server 127.0.0.1 80 50 51 real_server 172.16.100.40 80 { 52 weight 1 53 HTTP_GET { 54 url { 55 path / 56 status_code 200 57 } 58 connect_timeout 3 59 nb_get_retry 3 60 delay_before_retry 3 61 } 62 } 63 real_server 172.16.100.50 80 { 64 weight 2 65 HTTP_GET { 66 url { 67 path / 68 status_code 200 69 } 70 connect_timeout 3 71 nb_get_retry 3 72 delay_before_retry 3 73 } 74 } 75 }
将keepalived1节点中/etc/keepalived/keepalived.conf文件复制keepalived2节点中，将state MASTER改为state BACKUP，priority 100改为priority 90即可
# vim /etc/keepalived/notify.sh
1 #!/bin/bash 2 # 3 4 vip=172.16.20.100 5 contact='root@localhost' 6 7 notify() { 8 mailsubject="`hostname` to be $1: $vip floating" 9 mailbody="`date '+%F %H:%M:%S'`: vrrp transition, `hostname` changed to be $1" 10 echo $mailbody | mail -s "$mailsubject" $contact 11 } 12 13 case "$1" in 14 master) 15 notify master 16 exit 0 17 ;; 18 backup) 19 notify backup 20 exit 0 21 ;; 22 fault) 23 notify fault 24 exit 0 25 ;; 26 *) 27 echo 'Usage: `basename $0` {master|backup|fault}' 28 exit 1 29 ;; 30 esac
也将此脚本复制到keepalived2节点中
启动两个keepalived节点：
# systemctl start keepalived; ssh knode2.lushenle.com 'systemctl start keepalived'
此时可查看自动生成的ipvs规则
# ipvsadm -L -n
两台Real Server中修改内核参数，将Real Server中VIP配置在ens32网卡的别名ens32:0上，并限制其不能响应对VIP地址的请求：
# vim set.sh
1 #!/bin/bash 2 # 3 vip=172.16.20.100 4 ifconfig ens32:0 $vip broadcast $vip netmask 255.255.255.255 up 5 route add -host $vip ens32:0 6 echo 1 > /proc/sys/net/ipv4/conf/ens32/arp_ignore 7 echo 1 > /proc/sys/net/ipv4/conf/all/arp_ignore 8 echo 2 > /proc/sys/net/ipv4/conf/ens32/arp_announce 9 echo 2 > /proc/sys/net/ipv4/conf/all/arp_announce
为Real Server1提供内容，因为Real Server2位所有节点的yum源，就懒得去修改了：
# echo "<h1>This is on real server1<h1>" > /var/www/html/index.html
启动两个Real Server的服务：
# systemctl start httpd; ssh node3.lushenle.com 'systemctl start httpd'
客户端进行访问、测试
