LVS可以实现负载均衡，但是不能够进行健康检查，比如一个rs出现故障，LVS 仍然会把请求转发给故障的rs服务器，这样就会导致请求的无效性。keepalive 软件可以进行健康检查，而且能同时实现 LVS 的高可用性，解决 LVS 单点故障的问题，其实 keepalive 就是为 LVS 而生的。

LVS-DR+Keepalived

一、实验环境：

Keepalived1 + lvs1(Director1)：192.168.0.48Keepalived2 + lvs2(Director2)：192.168.0.58Real server1：192.168.0.18Real server2：192.168.0.28VIP: 192.168.0.38

二、安装系统软件

LB+LVS+Keepalived的两个节点        yum install ipvsadm keepalived -yRS+Nginx的两个节点        yum install epel-release -y        yum install nginx -y        chkconfig nginx on        service nginx start

三、设置配置脚本

两个RS节点# vim /usr/local/sbin/lvs_dr_rs.sh#! /bin/bashvip=192.168.0.38ifconfig lo:0 $vip broadcast $vip netmask 255.255.255.255 uproute add -host $vip lo:0echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignoreecho "2" >/proc/sys/net/ipv4/conf/lo/arp_announceecho "1" >/proc/sys/net/ipv4/conf/all/arp_ignoreecho "2" >/proc/sys/net/ipv4/conf/all/arp_announce2节点rs 上分别执行脚本：bash /usr/local/sbin/lvs_dr_rs.sh两个keepalived节点：Master节点：vim /etc/keepalived/keepalived.confvrrp_instance VI_1 {    state MASTER    interface eth0    virtual_router_id 51    priority 100    advert_int 1    authentication {        auth_type PASS        auth_pass 1111    }    virtual_ipaddress {        192.168.0.38    }}virtual_server 192.168.0.38 80 {    delay_loop 6    lb_algo rr    lb_kind DR    persistence_timeout 0    protocol TCPreal_server 192.168.0.18 80 {        weight 1        TCP_CHECK {            connect_timeout 10            nb_get_retry 3            delay_before_retry 3            connect_port 80        }    }real_server 192.168.0.28 80 {        weight 1        TCP_CHECK {            connect_timeout 10            nb_get_retry 3            delay_before_retry 3            connect_port 80        }    }}backup节点：vim /etc/keepalived/keepalived.confvrrp_instance VI_1 {    state BACKUP    interface eth0    virtual_router_id 51    priority 90    advert_int 1    authentication {        auth_type PASS        auth_pass 1111    }    virtual_ipaddress {        192.168.0.38    }}virtual_server 192.168.0.38 80 {    delay_loop 6    lb_algo rr    lb_kind DR    persistence_timeout 0    protocol TCPreal_server 192.168.0.18 80 {        weight 1        TCP_CHECK {            connect_timeout 10            nb_get_retry 3            delay_before_retry 3            connect_port 80        }    }real_server 192.168.0.28 80 {        weight 1        TCP_CHECK {            connect_timeout 10            nb_get_retry 3            delay_before_retry 3            connect_port 80        }    }}keepalived的2个节点执行如下命令，开启转发功能：# echo 1 > /proc/sys/net/ipv4/ip_forward先主后从分别启动keepaliveservice keepalived start

三、验证结果