部署LVS-DR集群实现负载均衡实例

一：配置网络环境

1）设置Web服务器网络参数

# vim /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth0
ONBOOT=yes
BOOTPROTO=static
IPADDR=192.168.0.1
NETMASK=255.255.255.0
GATEWAY=192.168.0.254
DNS1=202.106.0.20

# vim /etc/sysconfig/network-scripts/ifcfg-lo:0
DEVICE=lo:0
ONBOOT=yes
BOOTPROTO=static
IPADDR=192.168.0.253
NETMASK=255.255.255.255

# vim /etc/sysctl.conf
.. ..
net.ipv4.conf.all.arp_ignore = 1
net.ipv4.conf.lo.arp_ignore = 1
net.ipv4.conf.lo.arp_announce = 2
net.ipv4.conf.all.arp_announce = 2

# sysctl -p

# systemctl restart NetworkManager

2）自定义Web页面

# echo “192.168.0.1” > /var/www/html/index.html
# echo “192.168.0.2” > /var/www/html/index.html

3）启动Web服务器软件

[root@web1 ~]# systemctl start httpd; systemctl enable httpd

[root@web2 ~]# systemctl start httpd; systemctl enable httpd

4)设置LVS调度器网络参数

# vim /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth0
ONBOOT=yes
BOOTPROTO=static
IPADDR=192.168.0.10
NETMASK=255.255.255.0
GATEWAY=192.168.0.254
DNS1=202.106.0.20

#vim /etc/sysconfig/network-scripts/ifcfg-eth0:0
DEVICE=eth0:0
ONBOOT=yes
BOOTPROTO=static
IPADDR=192.168.0.253
NETMASK=255.255.255.0
GATEWAY=192.168.0.254
DNS1=202.106.0.20

# systemctl restart NetworkManager

5）设置Linux路由器网络参数

# vim /etc/sysconfig/network-scripts/ifcfg-eth0

DEVICE=eth0
ONBOOT=yes
BOOTPROTO=static
IPADDR=202.114.106.20
DNS1=202.106.0.20

# vim /etc/sysconfig/network-scripts/ifcfg-eth1
DEVICE=eth0
ONBOOT=yes
BOOTPROTO=static
IPADDR=192.168.0.254
NETMASK=255.255.255.0
DNS1=202.106.0.20

# systemctl restart NetworkManager

6）设置Linux路由器的SNAT、DNAT功能

# sed -i '/ip_forward/s/0/1/'  sysctl.conf  //开启路由转发

# sysctl -p
# iptables -t nat -A POSTROUTING -s 192.168.0.0/24 -p tcp –j SNAT --to-source 202.114.106.20
# iptables -t nat -A PREROUTING -d 202.114.106.20 -p tcp --dport 80 –j DNAT --to-destination 192.168.0.253:80
# service iptables save

二：调度器安装软件并启动服务

1）安装软件

# rpm –ihv ipvsadm-1.25-10.el6.x86_64.rpm

2）启动服务

# systemctl start ipvsadm
# systemctl enable ipvsadm

三：部署LVS-DR模式调度器

1）创建集群服务器

# ipvsadm -A -t 192.168.0.253:80 -s wrr

2）添加真实服务器

# ipvsadm -a -t 192.168.0.253:80 -r 192.168.0.1 -g -w 1
# ipvsadm -a -t 192.168.0.253:80 -r 192.168.0.2 -g -w 2

3）查看规则列表，并保存规则

# ipvsadm –Ln
# ipvsadm-save -n > /etc/sysconfig/ipvsadm

四：客户端测试

客户端使用curl命令反复连接http://202.114.106.20，查看访问的页面是否会轮询到不同的后端真实服务器。