Lvs+keepalived 高可用性负载均衡配置

Lvs+keepalived 高可用性负载均衡配置前言* 随着互联网的发展，提供用户访问的web服务器，必须要保证每天24不间断服务，访问量不断增加，有什么好的web架构既能实现高可用性负载均衡，而且价格又是免费的呢？答案有木有？有！lvs+keepalived 是不错的选择！一、实验环境：4台centos 5.4 ，以及简单的拓扑图：LVS-Master 192.168.2.108LVS-BACKUP 192.168.2.109LVS-DR-VIP 192.168.2.100WEB1-Realserver 192.168.2.79WEB2-Realserver 192.168.2.80二、安装ipvsadm+keepalived,用脚本自动安装：由于我们使用的是lvs+keepalived，所以这里不需要配置lvs-dr脚本，直接在keepalived.conf里面配置即可！#!/bin/sh###脚本编写目的:自动安装lvs+keepalived###编写时间: 2011年7月6日17:25:39###初稿人:wugk###定义变量DIR1=/usr/srcDIR2=/usr/localcat << EOF++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++Welcome to use Linux installed a key LVS+KEEPALIVED shells scripts+++++++++++++++++++++*************************++++++++++++++++++++++++EOFif[ $UID -ne 0 ];thenecho “This script must use root user ,please exit……”sleep 2exit 0fidownload (){cd $DIR1 && wget -c /software/kernel-2.6/ipvsadm-1.24.tar.gz /software/keepalived-1.1.15.tar.gzif[ $? = 0 ];thenecho "Download LVS Code is OK!"elseecho "Download LVS Code is failed,Please check!"exit 1fi}ipvsadm_install (){ln -s $DIR1/kernels/2.6.* $DIR1/linuxcd $DIR1 && tar xzvf ipvsadm-1.24.tar.gz &&cd ipvsadm-1.24 && make && make installif[ $? -eq 0 ];thenecho "Install ipvsadm success,please waiting install keepalived ..............."elseecho "Install ipvsadm failed ,please check !"exit 1fi}keepalived_install (){cd $DIR1 && tar -xzvf keepalived-1.1.15.tar.gz &&cd keepalived-1.1.15 && ./configure && make && make installif[ $? -eq 0 ];thenecho "Install keepalived success,please waiting configure keepalived ..............."elseecho "Install keepalived failed ,please check install version !"exit 1fi}######如果以上软件包编译报错的话，请检查相关的版本跟系统版本之间的关系，然后手动下载安装.keepalived_config (){cp $DIR2/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/ && cp $DIR2/etc/sysconfig/keepalived /etc/sysconfig/ && mkdir -p /etc/keepalived &&cp $DIR2/etc/keepalived/keepalived.conf/etc/keepalived/ && cp $DIR2/sbin/keepalived /usr/sbin/if[ $? -eq 0 ];thenecho "Keepalived system server config success!"elseecho "Keepalived system server config failed ,please check keepalived!"exit 1fi}PS3="Please select Install Linux Packages:"select option in download ipvsadm_install keepalived_install keepalived_configdo$optiondone以上脚本分别在lvs-master和lvs-backup上执行安装。

三、配置keepalived.conf：内容如下是lvs-master配置也可以参考配置：/download/keepalived.conf可以直接打开! Configuration File for keepalivedglobal_defs {notification_email {wgkgood@}notification_email_from wgkgood@smtp_server 127.0.0.1smtp_connect_timeout 30router_id LVS_DEVEL}# VIP1vrrp_instance VI_1 {state MASTERinterface eth0lvs_sync_daemon_inteface eth0virtual_router_id 51priority 100advert_int 5authentication {auth_type PASSauth_pass 1111}virtual_ipaddress {192.168.2.100}}#REAL_SERVER_1virtual_server 192.168.2.100 80 {delay_loop 6lb_algo wlclb_kind DRpersistence_timeout 60protocol TCPreal_server 192.168.2.79 80 {weight 100TCP_CHECK {connect_timeout 10nb_get_retry 3delay_before_retry 3connect_port 80}}#REAL_SERVER_2real_server 192.168.2.80 80 {weight 100TCP_CHECK {connect_timeout 10nb_get_retry 3delay_before_retry 3connect_port 80}}}注意***Lvs-backup端同样配置，只需要更改state MASTER为state BACKUP，修改priority 100为priority 90即可。

四、分别在web1、web2上配置好apache，然后分别执行如下脚本：如下的VIP1指的是lvs-dr-vip地址，及对外提供访问的虚拟ip：#!/bin/shPS3="Please Choose whether or not to start a realserver VIP1 configuration:"select i in "start" "stop"docase "$i" instart)read -p "Please enter the virtual server IP address:" VIP1ifconfig lo:0 $VIP1 netmask 255.255.255.255 broadcast $VIP1/sbin/route add -host $VIP1 dev lo:0echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignoreecho "2" >/proc/sys/net/ipv4/conf/lo/arp_announceecho "1" >/proc/sys/net/ipv4/conf/all/arp_ignoreecho "2" >/proc/sys/net/ipv4/conf/all/arp_announcesysctl -p >/dev/null 2>&1echo "RealServer Start OK"exit 0;;stop)ifconfig lo:0 downroute del $VIP1 >/dev/null 2>&1echo "0" >/proc/sys/net/ipv4/conf/lo/arp_ignoreecho "0" >/proc/sys/net/ipv4/conf/lo/arp_announceecho "0" >/proc/sys/net/ipv4/conf/all/arp_ignoreecho "0" >/proc/sys/net/ipv4/conf/all/arp_announceecho "RealServer Stoped"exit 1;;*)echo "Usage: $0 {start|stop}"exit 2esacdone脚本会提示是否启动，按1即启动，然后输入vip地址 192.168.2.100 ，用ifconfig你会看到：lo:0的ip即表示配置ip成功。