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更新时间：2021-12-11 21:28:31
前言* 随着互联网飞速的发展，互联网WEB服务器，必须要保证每天7x24x365不间断服务，随着人数不断的增加，有什么好的WEB前端架构呢？既能实现高可用、负载均衡、成本有最低廉呢？答案有木有呢？LVS+Keepalived是一个非常不错的前端均衡选择。（今天来研究一下如何快速配置LVS及日常的维护，供参考！）
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LVS-Master 192.168.2.108
LVS-BACKUP 192.168.2.109
LVS-DR-VIP 192.168.2.100
WEB1-Realserver 192.168.2.79
WEB2-Realserver 192.168.2.80
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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！
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#!/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 ];then
echo “This script must use root user ,please exit……”
sleep 2
exit 0
fidownload (){cd $DIR1 && wget -c http://www.linuxvirtualserver.org/software/kernel-2.6/ipvsadm-1.24.tar.gz http://www.keepalived.org/software/keepalived-1.1.15.tar.gz
if[ $? = 0 ];then
echo "Download LVS Code is OK!"
elseecho "Download LVS Code is failed,Please check!"
exit 1
fi}ipvsadm_install (){ln -s $DIR1/kernels/2.6.* $DIR1/linux
cd $DIR1 && tar xzvf ipvsadm-1.24.tar.gz &&cd ipvsadm-1.24 && make && make install
if[ $? -eq 0 ];then
echo "Install ipvsadm success,please waiting install keepalived ..............."
elseecho "Install ipvsadm failed ,please check !"
exit 1
fi}keepalived_install (){cd $DIR1 && tar -xzvf keepalived-1.1.15.tar.gz &&cd keepalived-1.1.15 && ./configure && make && make install
if[ $? -eq 0 ];then
echo "Install keepalived success,please waiting configure keepalived ..............."
elseecho "Install keepalived failed ,please check install version !"
exit 1
fi}######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[ $? -eq 0 ];then
echo "Keepalived system server config success!"
elseecho "Keepalived system server config failed ,please check keepalived!"
exit 1
fi}PS3="Please select Install Linux Packages:"
select option in download ipvsadm_install keepalived_install keepalived_config
do$optiondone |
以上脚本分别在lvs-master和lvs-backup上执行安装。
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! Configuration Filefor keepalivedglobal_defs { notification_email {
wgkgood@163.com
}
notification_email_from wgkgood@163.com
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id LVS_DEVEL
}# VIP1vrrp_instance VI_1 { state MASTER
interface eth0
lvs_sync_daemon_inteface eth0
virtual_router_id 51
priority 100
advert_int 5
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.2.100
}
}#REAL_SERVER_1virtual_server 192.168.2.100 80 {
delay_loop 6
lb_algo wlc
lb_kind DR
persistence_timeout 60
protocol TCP
real_server 192.168.2.79 80 {
weight 100
TCP_CHECK {
connect_timeout 10
nb_get_retry 3
delay_before_retry 3
connect_port 80
}
}#REAL_SERVER_2 real_server 192.168.2.80 80 {
weight 100
TCP_CHECK {
connect_timeout 10
nb_get_retry 3
delay_before_retry 3
connect_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。
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#!/bin/shPS3="Please Choose whether or not to start a realserver VIP1 configuration:"
select i in"start""stop"
docase"$i"in
start)read -p "Please enter the virtual server IP address:" VIP1
ifconfig lo:0 $VIP1 netmask 255.255.255.255 broadcast $VIP1
/sbin/route add -host $VIP1 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 >/dev/null 2>&1
echo "RealServer Start OK"
exit 0
;;stop)ifconfig lo:0 down
route del $VIP1 >/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"
exit 1
;;*)echo "Usage: $0 {start|stop}"
exit 2
esacdone |
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lo:0 Link encap:Local Loopback
inet addr:192.168.2.100 Mask:255.255.255.255
UP LOOPBACK RUNNING MTU:16436 Metric:1
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/etc/init.d/keepalived restart 查看lvs-master日志：在浏览器里面访问 http://192.168.2.100/ 即可！当你宕掉lvs-master后，lvs-backup会接管变成lvs-master提供服务，当lvs-master故障恢复后，lvs-backup又会变成原来的状态！
所安装的脚本可以在这里下载：在lvs-master和lvs-backup上执行http://chinaapp.sinaapp.com/download/lvs-keepalived.sh
在web服务器端执行http://chinaapp.sinaapp.com/download/realserver.sh
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六、实战建议
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为了解决脑裂问题，需要把主MASTER和备BACKUP各自的keepalived.conf配置文件里面的state 状态都改成BACKUP，优先级分别设置100和90。
我们常听说脑裂问题，到底什么是脑裂问题呢？在集群配置中的split-brain现象是指，主从之间互相检测不到心跳，同时抢占资源，导致服务无法正常访问的情况。所以我们还需要在主备keepalived.conf添加nopreempt 指令！ |
附realserver.sh脚本文件：
