基于直接路由模式(DR)的LVS

1、 实验目的： 客户机通过VIP 98访问服务器。Load Balancer将来自客户的访问按一定的负载均衡机制分发到realserver1和realserver2这两台实际提供服务的服务器。拓扑如下：配置过程如下：u 负载调度器（Master）上的设置1) 设定网卡IProotLoadBalancer # cat /etc/sysconfig/network-scripts/ifcfg-eth0 # Advanced Micro Devices AMD 79c970 PCnet32 LANCEDEVICE=eth0BOOTPROTO=staticIPADDR=211.10

2、0.1.196NETMASK=ONBOOT=yes2) 安装ipvsadm管理程序rootLoadBalancer # mount /dev/cdrom /mntmount: block device /dev/cdrom is write-protected, mounting read-onlyrootLoadBalancer # rpm -ivh /mnt/Cluster/ipvsadm-1.24-8.1.i386.rpm warning: /mnt/Cluster/ipvsadm-1.24-8.1.i386.rpm: Header V3 DSA signatu

3、re: NOKEY, key ID 37017186Preparing. # 100% 1:ipvsadm # 100%3) 配置VIP设定脚本、设置脚本可执行权限并运行rootLoadBalancer opt# cat vip.sh #!/bin/bash#description:set the VIP of directorserverVIP=98/sbin/ifconfig eth0:0 $VIP broadcast $VIP netmask 55 up/sbin/route add -host $VIP dev eth0:0rootLoa

4、dBalancer opt# chmod u+x /opt/vip.sh rootLoadBalancer opt# echo /opt/vip.sh /etc/rc.local /开机自启动rootLoadBalancer opt# /opt/vip.sh /运行脚本rootLoadBalancer opt# ifconfig eth0:0eth0:0 Link encap:Ethernet HWaddr 00:0C:29:C5:EC:AC inet addr:98 Bcast:98 Mask:55 UP BROADCAS

5、T RUNNING MULTICAST MTU:1500 Metric:1 Interrupt:59 Base address:0x20004) Ipvsadm命令工具的使用rootLoadBalancer # ipvsadm -A -t 98:80 -s rr -p 300-A 增加一个virtual service-t tcp协议，-u是udp协议-s 指定使用的算法 s rr指定使用轮叫算法(rr)，可以自行选择相应的算法-p 设置连接保持时间(将同一客户端的请求转发至同一个realserver,默认为300秒)rootLoadBalancer # ipvsadm

6、-a -t 98:80 -r 91:80 -grootLoadBalancer # ipvsadm -a -t 98:80 -r 92:80 -grootLoadBalancer # ipvsadm-save /etc/sysconfig/ipvsadm /保存设置命令-a 增加一个virtual server-g 是指定LVS使用DR直接路由模式，可自行修改(-i为TUN，-m为NAT)ipvsadm-save /etc/sysconfig/ipvsadm命令将上述ipvsadm设置保存到/etc/sys

7、config/ipvsadm文件以后，下次启动可直接执行“service ipvsadm start“命令，不再需要逐条输入命令。rootLoadBalancer # ipvsadm l /查看ipvsadm列表IP Virtual Server version 1.2.1 (size=4096)Prot LocalAddress:Port Scheduler Flags - RemoteAddress:Port Forward Weight ActiveConn InActConnTCP 98:http rr persistent 300 - 92

8、:http Route 1 0 0 - 91:http Route 1 0 0 u Realserver服务器上的设置IP地址设置好以后只需要运行以下脚本即可：rootrhel opt# cat lvs-dr #!/bin/bashVIP=98/sbin/ifconfig lo:0 $VIP broadcast $VIP netmask 55 up/sbin/route add -host $VIP dev lo:0echo 1 /proc/sys/net/ipv4/conf/lo/arp_ignoreecho 2 /pro

9、c/sys/net/ipv4/conf/lo/arp_announceecho 1 /proc/sys/net/ipv4/conf/all/arp_ignoreecho 2 /proc/sys/net/ipv4/conf/all/arp_announce#end 此脚本使realserver不响应arp请求，将脚本分别在realserver上设置开机自动执行rootrhel opt# chmod u+x lvs-dr rootrhel opt# ll lvs-dr -rwxr-r- 1 root root 342 Nov 24 10:24 lvs-drrootrhel opt# echo /o

10、pt/lvs-dr /etc/rc.local注：关闭arp响应的另外一个办法是修改配置文件/etc/sysctl.conf，把下面四句添加到文件最后：rootLoadBalancer # cat /etc/sysctl.conf | grep net.ipv4.confnet.ipv4.conf.lo.arp_ignore=1net.ipv4.conf.lo.arp_announce=2net.ipv4.conf.all.arp_ignore=1net.ipv4.conf.all.arp_announce=2创建测试页面：在realserver1上：rootrealserver1 # echo This is realserv