LVS + KeepAlived实现高可用负载均衡

上文已经介绍了lvs和keepalived的基本概念和用法，下面直接做lvs和keepalived来实现高可用负载均衡

配置：

1. 主备调度器安装软件

[root@lvs-keepalived-master ~]# yum -y install ipvsadm keepalived 
[root@lvs-keepalived-slave ~]# yum -y install ipvsadm keepalived
2. Keepalived
lvs-master
[root@lvs-keepalived-master ~]# vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived

global_defs {
   router_id lvs-keepalived-master    #辅助改为lvs-backup
}

vrrp_instance VI_1 {
    state MASTER
    interface ens33                #VIP绑定接口
    virtual_router_id 80         #VRID 同一组集群，主备一致          
    priority 100            #本节点优先级，辅助改为50
    advert_int 1            #检查间隔，默认为1s
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        172.16.147.101/24  # 可以写多个vip
    }
}

virtual_server 172.16.147.101 80 {    #LVS配置
	delay_loop 3
	lb_algo rr     #LVS调度算法
	lb_kind DR     #LVS集群模式（路由模式）
	net_mask 255.255.255.0
	protocol TCP      #健康检查使用的协议
	real_server 172.16.147.153 80 {
		weight 1
		inhibit_on_failure   #当该节点失败时，把权重设置为0，而不是从IPVS中删除
		TCP_CHECK {          #健康检查
			connect_port 80   #检查的端口
			connect_timeout 3  #连接超时的时间
			}
		}
	real_server 172.16.147.156 80 {
		weight 1
		inhibit_on_failure
		TCP_CHECK {
			connect_timeout 3
			connect_port 80
			}
		}
}

2. 备用机安装和配置

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

global_defs {
   router_id lvs-keepalived-slave
}

vrrp_instance VI_1 {
    state BACKUP
    interface ens33
    nopreempt                    #不抢占资源
    virtual_router_id 80
    priority 50
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        172.16.147.101/24
    }
}
virtual_server 172.16.147.101 80 {
	delay_loop 3
	lb_algo rr
	lb_kind DR
	net_mask 255.255.255.0
	protocol TCP
	real_server 172.16.147.153 80 {
		weight 1
		inhibit_on_failure
		TCP_CHECK {
			connect_port 80
			connect_timeout 3
			}
		}
	real_server 172.16.147.156 80 {
		weight 1
		inhibit_on_failure
		TCP_CHECK {
			connect_timeout 3
			connect_port 80
			}
		}
}

3. 启动KeepAlived

[root@lvs-keepalived-master ~]# systemctl start keepalived
[root@lvs-keepalived-master ~]# systemctl enable keepalived

[root@lvs-keepalived-master ~]# ipvsadm -Ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  172.16.147.101:80 rr persistent 20
  -> 172.16.147.153:80           Route   1      0          0         
  -> 172.16.147.156:80           Route   0      0          0

4. 所有RS配置(nginx1,nginx2)

[root@test-nginx1 ~]# yum install -y nginx
[root@test-nginx2 ~]# yum install -y nginx
[root@test-nginx1 ~]# echo "ip addr add dev lo 172.16.147.101/32" >> /etc/rc.local
[root@test-nginx1 ~]# echo "net.ipv4.conf.all.arp_ignore = 1" >> /etc/sysctl.conf
[root@test-nginx1 ~]# echo "net.ipv4.conf.all.arp_announce = 2" >> /etc/sysctl.conf
[root@test-nginx1 ~]# sysctl -p
[root@test-nginx1 ~]# echo "web1..." >> /usr/share/nginx/html/index.html
[root@test-nginx1 ~]# systemctl start nginx
[root@test-nginx1 ~]# chmod +x /etc/rc.local

上述步骤实现了两台机器的高可用并进行172.16.147.156和172.16.147.153的负载均衡