實驗環境

兩臺Keepalived伺服器，三臺提供http服務的節點伺服器
主排程器（192.168.3.4）
從排程器（192.168.3.5）
HTTP-1（192.168.3.1）
HTTP-2（192.168.3.2）
HTTP-3（192.168.3.3）

1. 主排程器：

	[[email protected] ~]# yum -y install keepalived ipvsadm
   ###如果交換機外網有獨立的IP可以不用指定虛擬IP###
   [[email protected] ~]# cd /etc/sysconfig/
 
network-scripts/
   [[email protected] ~]# cp ifcfg-ens32 ifcfg-ens32:0
   [[email protected] ~]# vim ifcfg-ens32:0			#配置虛擬IP地址
   NAME=ens32:0
   DEVICE=ens32:0
   ONBOOT=yes
   IPADDR=192.168.3.10
   NETMASK=255.255.255.0
   :wq!
   [[email protected] ~]# ifup ens32:0				#開啟虛擬IP
   [[email protected]
 
 ~]# ifconfig ens32:0			#檢視
   [[email protected] ~]# vim /etc/sysctl.conf			#調整/proc響應引數
   ...
   	net.ipv4.conf.all.send_redirects = 0
   	net.ipv4.conf.default.send_redirects = 0
   	net.ipv4.conf.ens32.send_redirects = 0
   	:wq!
   [[email protected] ~]# cd /etc/keepalived
   [[email protected]
 
 ~]# cp keepalived.conf keepalived.conf.bak
   [[email protected] ~]# systemctl enable keepalived.service 
   [[email protected] ~]# vim /etc/keepalived/keeplived.conf
   global_defs {
      router_id LVS_DR_1		#路由器名稱
   }

   vrrp_instance VI_1 {
       state MASTER
       interface ens32			#網絡卡
       virtual_router_id 1
       priority 100			#優先順序
       advert_int 1
       authentication {
           auth_type PASS
           auth_pass 123456		#匹配密碼
       }
       virtual_ipaddress {
           192.168.3.10			#VIP地址
       }
   }
   
   virtual_server 192.168.3.10 80 {
       delay_loop 6
       lb_algo rr
       lb_kind DR
       persistence_timeout 50
       protocol TCP
   
       real_server 192.168.3.1 80 {			#真實伺服器
           weight 1
           TCP_CHECK {
                   connect_port 80
                   connect_timeout 3
                   nb_get_retry 3
                   delay_before_retry 4
                   }
           }
       real_server 192.168.3.2 80 {
           weight 1
           TCP_CHECK {
                   connect_port 80
                   connect_timeout 3
                   nb_get_retry 3
                   delay_before_retry 4
                   }
           }
       real_server 192.168.3.3 80 {
           weight 1
           TCP_CHECK {
                   connect_port 80
                   connect_timeout 3
                   nb_get_retry 3
                   delay_before_retry 4
                   }
           }
   }
   :wq!
   [[email protected]MASTER ~]# systemctl restart keepalived.service
   [[email protected]MASTER ~]# ip a

2. 從排程器：

  [[email protected] ~]# yum -y install keeplived ipvsadm
  [[email protected] ~]# systemctl enable keepalived.service
  [[email protected] ~]# cd /etc/keepalived
  [[email protected] ~]# cp keepalived.conf keepalived.conf.bak
  [[email protected] ~]# vim /etc/keepalived/keeplived.conf
  global_defs { 
     router_id LVS_DR_2		#路由器名稱
  }
  
  vrrp_instance VI_1 {
      state BACKUP
      interface ens32			#網絡卡
  	virtual_router_id 1
  	priority 99			#優先順序
  	advert_int 1
  	authentication {
  	    auth_type PASS
  	    auth_pass 123456		#匹配密碼
  	}
  	virtual_ipaddress {
  	    192.168.3.10		#漂移地址
  	}
  }
  
  virtual_server 192.168.3.10 80 {		#真實伺服器
      delay_loop 6
      lb_algo rr
      lb_kind DR
      persistence_timeout 50
      protocol TCP
  
      real_server 192.168.3.1 80 {
          weight 1
          TCP_CHECK {
                  connect_port 80
                  connect_timeout 3
                  nb_get_retry 3
                  delay_before_retry 4
                  }
          }
      real_server 192.168.3.2 80 {
          weight 1
          TCP_CHECK {
                  connect_port 80
                  connect_timeout 3
                  nb_get_retry 3
                  delay_before_retry 4
                  }
          }
      real_server 192.168.3.3 80 {
          weight 1
          TCP_CHECK {
                  connect_port 80
                  connect_timeout 3
                  nb_get_retry 3
                  delay_before_retry 4
                  }
          }
  }
  :wq!
  	[[email protected] ~]# systemctl restart keepalived

3. 節點伺服器 ：

 [[email protected] ~]# cd /etc/sysconfig/network-scripts/
 [[email protected] ~]#  cp ifcfg-lo ifcfg-lo:0
 [[email protected] ~]# vim ifcfg-lo:0			#配置虛擬IP，要和LVS虛擬IP一致，子網掩碼全為1
 	DEVICE=lo:0
 	IPADDR=192.168.3.5
 	NETMASK=255.255.255.255 
 	:wq!
 [[email protected] ~]# ifup lo:0
 [[email protected] ~]# ifconfig lo:0
 [[email protected] ~]# vim /etc/rc.local 		#新增VIP本地訪問路由	
 	...
 	/sbin/route add -host 192.168.3.10 dev lo:0
 	:wq!
 [[email protected] ~]# route add -host 192.168.3.10 dev lo:0	
 [[email protected] ~]# vim /etc/sysctl.conf			#調整/proc響應引數
 	...
 	net.ipv4.conf.all.arp_ignore = 1
 	net.ipv4.conf.all.arp_announce = 2
 	net.ipv4.conf.default.arp_ignore = 1
 	net.ipv4.conf.default.arp_announce = 2
 	net.ipv4.conf.lo.arp_ignore = 1
 	net.ipv4.conf.lo.arp_announce = 2
 	:wq!
 [[email protected] ~]# sysctl -p

4. 測試：
   客戶端訪問“http://192.168.3.10”
   關閉主排程器，客戶端任然能夠正常訪問節點伺服器
   關閉一臺節點伺服器，客戶端任然能正常訪問其他節點伺服器