拓扑结构：

环境准备：
Centos6.5x86_64 关闭防火墙和Selinux

VIP：192.168.1.200/24
node5: eth0:192.168.1.190/24
node1：eth1:192.168.1.191/24
node2：RIP：eth0: 192.168.19.2/24
node3：RIP：eth0: 192.168.19.3/24   所有节点网关/DNS都为：192.168.1.1

每个服务器的hosts文件

# cat /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
192.168.19.190    node5.luo.com    node5  
192.168.19.191    node1.luo.com    node1  
192.168.19.192    node2.luo.com    node2  
192.168.19.193    node3.luo.com    node3

时间同步（每个节点都需要做）
为方便实验使用笔记本作为时间服务器，参考http://blog.csdn.net/irlover/article/details/7314530
ntpdate 192.168.1.105
如我想每隔10分钟和win7同步时间可以使用crontab -e 编辑crontab工作内容如下：
*/10 * * * * /usr/sbin/ntpdate 192.168.1.105 &>/dev/null&&/sbin/hwclock-w

node5与node1安装配置基本相同
在两个keepalived+nginx主机上都需安装keepalkved和nginx服务

# yum install -y keepalived nginx

配置nginx为反向代理服务器（两台都配置）
编辑nginx.conf配置文件
# vim /etc/nginx/nginx.conf
在nginx.conf配置文件中的http段内添加如下内容

upstream webservers {
    server 192.168.1.192;
    server 192.168.1.193;
}
server {
    listen 80;
    server_name www.luo.com;
    location / {
        proxy_pass http://webservers;
        proxy_set_header X-Real-IP $remote_addr;
    }
}

# service nginx start

配置keepalived

node5(192.168.19.190)的配置文件内容为：

# cat /etc/keepalived/keepalived.conf

! Configuration File for keepalived
global_defs {
   notification_email {
   root@localhost
   }
   notification_email_from keepalived@luo.com
   smtp_server 127.0.0.1
   smtp_connect_timeout 30
   router_id LVS_DEVEL
}
vrrp_instance VI_1 {
    state MASTER
    interface eth0
    virtual_router_id 15
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 123456
    }
    virtual_ipaddress {
    192.168.1.200/24
    }
    notify_master "/etc/init.d/nginx start"
    notify_backup "/etc/init.d/nginx stop"
    notify_fault "/etc/init.d/nginx stop"
}

# cat /etc/keepalived/keepalived.conf

global_defs {
   notification_email {
   root@localhost
   }
   notification_email_from keepalived@luo.com
   smtp_server 127.0.0.1
   smtp_connect_timeout 30
   router_id LVS_DEVEL
}
vrrp_instance VI_1 {
    state BACKUP
    interface eth1
    virtual_router_id 16
    priority 99
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 123456
    }
    virtual_ipaddress {
    192.168.1.200/24
    }
    notify_master "/etc/init.d/nginx start"
    notify_backup "/etc/init.d/nginx stop"
    notify_fault "/etc/init.d/nginx stop"
}

编辑node2测试页面

# echo "<h1>node2.luo.com</h1>" > /var/www/html/index.html
# service httpd restart
# curl http://192.168.1.192

编辑node3测试页面

#  echo "<h1>node3.luo.com</h1>" > /var/www/html/index.html
# service httpd restart
# curl http://192.168.1.193

测试：
启动node5与node1的keepalived服务

# service keepalived start

访问192.168.1.200，多刷新几次就可以查看到两台web服务器的页面了
 

停止node5的keepalived服务，查看node1的相关信息，发现VIP已经到node1上面了
[root@node5 ~]# service keepalived stop

访问192.168.1.200，多刷新几次就可以查看到两台web服务器的页面了

keepalived高可用反向代理的nginx-实例