一、环境介绍
VIP
192.168.183.100
lvs-master 192.168.183.128
lvs-backup 192.168.183.129
realserver1 192.168.183.130
realserver2 192.168.183.131
我是用虚机做的测试，四台虚机全部最小化安装CentOS 5.5 64bit，网络模式为NAT。
本次测试LVS为DR模式。
二、部署LVS+Keepalived
1.安装ipvsadm
#yum -y install ipvsadm
2.安装keepalived
#yum -y install kernel-devel openssl-devel
现在最新稳定版本keepalived，本次测试使用版本为keepalived-1.2.2
先建立内核目录软连接，否则./configure会报错。
ln -s /usr/src/kernels/2.6.18-194.el5-x86_64/ /usr/src/linux
解压keepalived-1.2.2.tar.gz
进入源码目录，./configure
完成之后显示如下信息则configure成功。
Use IPVS Framework : Yes
IPVS sync daemon support : Yes
然后make && make install
我在这里遇到了一个错误，有人说是版本的问题，是如下处理的：
vi keepalived/libipvs-2.6/ip_vs.h
找到下面一行：
#include <linux/types.h> /* For __beXX types in userland */
把他放到下面一行的下面：
#include <sys/types.h>
这样便可以编译过去了。
三、配置lvs+Keepalived
1.拷贝配置文件及命令文件
# cp /usr/local/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/
# cp /usr/local/etc/sysconfig/keepalived /etc/sysconfig/
# mkdir /etc/keepalived
# cp /usr/local/etc/keepalived/keepalived.conf /etc/keepalived/
# cp /usr/local/sbin/keepalived /usr/sbin/
# chkconfig –add keepalived
# chkconfig –level 2345 keepalived on
2.撰写keepalived.conf
# vi /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
notification_email {
wanghailong@eloomobile.com
}
notification_email_from localhost
smtp_server 192.168.1.99
smtp_connect_timeout 30
router_id LVS_MASTER
}
vrrp_instance VI_1 {
state MASTER
interface eth0
virtual_router_id 51
priority 101
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.183.100
}
}
virtual_server 192.168.183.100 80 {
delay_loop 6
lb_algo wrr
lb_kind DR
nat_mask 255.255.255.0
persistence_timeout 50
protocol TCP
real_server 192.168.183.130 80 {
weight 3
TCP_CHECK {
connect_timeout 10
nb_get_retry 3
delay_before_retry 3
connect_port 80
}
}
real_server 192.168.183.131 80 {
weight 1
TCP_CHECK {
connect_timeout 10
nb_get_retry 3
delay_before_retry 3
connect_port 80
}
}
}
这个是MASTER主机的配置，在BACKUP上基本相同，仅红色标记部分做相应更改即可，其他完全与MASTER相同。
四、RealServer配置
RealServer请自行安装相关WEB服务。
RealServer上面只需要执行以下脚本即可。
#! /bin/bash
SNS_VIP=192.168.183.100
/etc/rc.d/init.d/functions
case "$1" in
start)
/sbin/ifconfig lo:0 $SNS_VIP netmask 255.255.255.255 broadcast $SNS_VIP up
/sbin/route add -host $SNS_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
syscty -p > /dev/null 2>&1
echo "RealServer Start Ok"
;;
stop)
ifconfig lo:0 down
route del $SNS_VIP >/dev/null 2>&1
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 "RealServer Stoped"
;;
*)
echo "Usage: $0 {start|stop}"
exit 1
esac
exit 0
启动后检查是否监听虚拟IP，如果有监听虚拟IP，说明启动成功。否则，请检查。
至此所有的配置完毕。
五、测试
在主备机器上都启动keepalived，在RealServer上启动Web服务和监听虚拟IP。
测试在停止其中之一的WEB服务时，停止LVS-MASTER keepalived服务时。访问虚拟IP，看是否可以返回结果，并且观察RealServer WEB服务的访问日志。
简单的测试就到此结束。以后会继续关注这方面的问题。
本文出自 “放逐天涯” 博客，请务必保留此出处http://andy2018.blog.51cto.com/3690563/774047
LVS+Keepalived实现负载均衡及双机热备
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