通过LVS实现http的负载均衡

通过LVS实现http的负载均衡

1、摘要

本文不考虑双机互备，通过脚本和lvs实现http的负载均衡，实际生产环境使用集群

2、安装

1）、软件包准备

ipvsadm-1.26.tar.gz

httpd-2.2.23.tar.gz

2)、配置Director Server

a、检查kernel是否已经支持LVS的ipvs模块

# modprobe -l |grep ipvs

kernel/net/netfilter/ipvs/ip_vs.ko

kernel/net/netfilter/ipvs/ip_vs_rr.ko

kernel/net/netfilter/ipvs/ip_vs_wrr.ko

kernel/net/netfilter/ipvs/ip_vs_lc.ko

kernel/net/netfilter/ipvs/ip_vs_wlc.ko

kernel/net/netfilter/ipvs/ip_vs_lblc.ko

kernel/net/netfilter/ipvs/ip_vs_lblcr.ko

kernel/net/netfilter/ipvs/ip_vs_dh.ko

kernel/net/netfilter/ipvs/ip_vs_sh.ko

kernel/net/netfilter/ipvs/ip_vs_sed.ko

kernel/net/netfilter/ipvs/ip_vs_nq.ko

kernel/net/netfilter/ipvs/ip_vs_ftp.ko

kernel/net/netfilter/ipvs/ip_vs_pe_sip.ko

b、在Director Server中安装LVS

# ln -s /usr/src/kernels/2.6.32-431.el6.x86_64/ /usr/src/linux #解决ipvsadm找不到内核

# yum install -y libnl*

# yum install -y popt*

# rpm -ivh popt-static-1.13-7.el6.x86_64.rpm #前三步是解决安装ipvsadm-1.26报错的软件包

# tar zxvf ipvsadm-1.26.tar.gz

# cd ipvsadm-1.26

# make

# make install

# ipvsadm --help #出现ipvsadm帮助提示表示ipvsadm已经安装成功

c、lvs启停脚本

vim /etc/init.d/lvsDR

#!/bin/sh

# description: Start LVS of Director server

VIP=10.0.2.200

RIP1=10.0.2.203

RIP2=10.0.2.204

chmod 755 /etc/rc.d/init.d/functions

/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

/sbin/route add -host $VIP dev eth0:0

echo "1" >/proc/sys/net/ipv4/ip_forward 

#Clear IPVS table

/sbin/ipvsadm -C

#set LVS

/sbin/ipvsadm -A -t $VIP:80 -s rr 

/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/route del -host $VIP dev eth0:0

        /sbin/ifconfig eth0:0 down

        ;;

    *)

        echo "Usage: $0 {start|stop}"

        exit 1

esac

# chmod 755 /etc/init.d/lvsDR

# /etc/init.d/lvsDR start

# service ipvsadm save #保存lvs记录到/etc/sysconfig/ipvsadm中

# service ipvsadm start

3)、配置Real Server服务器

a、安装http服务

# tar -zxvf httpd-2.2.23.tar.gz

# cd httpd-2.2.23

# ./configure --prefix=/usr/local/apache

# make && make install

b、配置httpd

# cp /usr/local/apache/bin/apachectl /etc/init.d/httpd

# vim /etc/init.d/httpd

修改文件，在文件中'#!/bin/sh'后面加入下面两条规则：

#!/bin/sh

#

# chkconfig: 2345 85 15

# description: Apache is a World Wide Web Server

#

# chkconfig --add httpd

# chkconfig --list httpd

# service httpd start

c、配置vip和arp

# vim /etc/init.d/lvsrs

#!/bin/bash

#description : Start Real Server 

VIP=10.0.2.200

/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

/sbin/route add -host $VIP dev lo:0

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

sysctl -p

;;

stop)

/sbin/ifconfig lo:0 down

/sbin/route del -host $VIP dev lo:0

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

# chmod 755 /etc/init.d/lvsrs

# /etc/init.d/lvsrs start