LVS负载均衡配置

资源：
lvs server: 10.10.10.20
real server: 10.10.10.21和10.10.10.22
vip: 10.10.10.30 （三台机器都使用虚拟IP 30）
real server上分别安装了apache2.2

1. 安装ipvsadm
1)下载安装包
http://www.linuxvirtualserver.org/software/kernel-2.6/ipvsadm-1.24-6.src.rpm
2)使用命令rpmbuild --rebuild ipvsadm-1.24-6.src.rpm
#rpmbuild --rebuild ipvsadm-1.24-6.src.rpm
会提示有警告和错误 忽略
3)vi /usr/src/redhat/SPECS/ipvsadm.spec
将第7行Copyright修改为License
保存退出
4)建立软连接ln -s /usr/src/kernels/2.6.18-128.el5-i686/ /usr/src/linux，注意源目录地址。
#ln -s /usr/src/kernels/2.6.18-128.el5-i686/ /usr/src/linux
5）生成二进制安装包
#rpmbuild -ba /usr/src/redhat/SPECS/ipvsadm.spec
6）安装ipvsadm
#rpm -ivh /usr/src/redhat/RPMS/i386/ipvsadm-1.24-6.i386.rpm
2. lvs server配置
执行命令：vi /etc/init.d/lvs
将如下代码复制进去：
==============================================================================
#!/bin/sh
# description: Start LVS of Director server
VIP=10.10.10.30
RIP1=10.10.10.21
RIP2=10.10.10.22
./etc/rc.d/init.d/functions
case "$1" in
    start)
        echo " start LVS of Director Server"
# set the Virtual  IP Address and sysctl parameter
/sbin/ifconfig eth0:0 $VIP broadcast $VIP netmask 255.255.255.255 up
       echo "1" >/proc/sys/net/ipv4/ip_forward
#Clear IPVS table
       /sbin/ipvsadm -C
#set LVS
/sbin/ipvsadm -A -t $VIP:80 -s rr -p 600
/sbin/ipvsadm -a -t $VIP:80 -r $RIP1:80 -g
/sbin/ipvsadm -a -t $VIP:80 -r $RIP2:80 -g
#Run LVS
      /sbin/ipvsadm
       ;;
    stop)
        echo "close LVS Directorserver"
        echo "0" >/proc/sys/net/ipv4/ip_forward
        /sbin/ipvsadm -C
        /sbin/ifconfig eth0:0 down
        ;;
    *)
        echo "Usage: $0 {start|stop}"
        exit 1
esac
==============================================================================
执行命令启动： service lvs start
停止命令：service lvs stop
3. lvs real server配置
执行命令：vi /etc/init.d/lvsrs
将如下内容复制进去：
==============================================================================
#!/bin/bash
#description : Start Real Server
VIP=10.10.10.30
./etc/rc.d/init.d/functions
case "$1" in
    start)
        echo " Start LVS  of  Real Server"
/sbin/ifconfig lo:0 $VIP broadcast $VIP netmask 255.255.255.255 up
        echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignore
        echo "2" >/proc/sys/net/ipv4/conf/lo/arp_announce
        echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore
        echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce
        ;;
    stop)
        /sbin/ifconfig lo:0 down
        echo "close LVS Director server"
        echo "0" >/proc/sys/net/ipv4/conf/lo/arp_ignore
        echo "0" >/proc/sys/net/ipv4/conf/lo/arp_announce
        echo "0" >/proc/sys/net/ipv4/conf/all/arp_ignore
        echo "0" >/proc/sys/net/ipv4/conf/all/arp_announce
        ;;
    *)
        echo "Usage: $0 {start|stop}"
        exit 1
esac
==============================================================================
执行命令启动： service lvsrs start
停止命令：service lvsrs stop

访问虚拟IP 10.10.10.30时，访问会被轮流分配到21和22上。该配置属于DR方式，所以三台服务器必须都在一个交换机下，不能跨网段。