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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！）
| 1 2 3 4 5 | 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 |
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！
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 | #!/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/src DIR2=/usr/local cat << EOF ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++Welcome to use Linux installed a key LVS+KEEPALIVED shells scripts +++++++++++++++++++++*************************++++++++++++++++++++++++ EOF if [ $UID -ne 0 ];then echo “This script must use root user ,please exit……” sleep 2 exit 0 fi download () { 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!" else echo "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 ..............." else echo "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 ..............." else echo "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!" else echo "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 $option done |
以上脚本分别在lvs-master和lvs-backup上执行安装。
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 | ! Configuration Filefor keepalived global_defs { notification_email { wgkgood@ 163 .com } notification_email_from wgkgood@ 163 .com smtp_server 127.0 . 0.1 smtp_connect_timeout 30 router_id LVS_DEVEL } # VIP1 vrrp_instance VI_1 { state MASTER interface eth0 lvs_sync_daemon_inteface eth0 virtual_router_id 51 priority 100 advert_int 5 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168 . 2.100 } } #REAL_SERVER_1 virtual_server 192.168 . 2.100 80 { delay_loop 6 lb_algo wlc lb_kind DR persistence_timeout 60 protocol TCP real_server 192.168 . 2.79 80 { weight 100 TCP_CHECK { connect_timeout 10 nb_get_retry 3 delay_before_retry 3 connect_port 80 } } #REAL_SERVER_2 real_server 192.168 . 2.80 80 { weight 100 TCP_CHECK { connect_timeout 10 nb_get_retry 3 delay_before_retry 3 connect_port 80 } } } |
注意***Lvs-backup端同样配置，只需要更改state MASTER为state BACKUP，修改priority 100为priority 90即可。
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 | #!/bin/sh PS3= "Please Choose whether or not to start a realserver VIP1 configuration:" select i in "start" "stop" do case "$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 esac done |
| 1 2 3 | lo: 0 Link encap:Local Loopback inet addr: 192.168 . 2.100 Mask: 255.255 . 255.255 UP LOOPBACK RUNNING MTU: 16436 Metric: 1 |
| 1 2 3 4 5 | /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 |
六、实战建议
| 1 2 3 4 | 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：
转载地址：http://qltyx.baihongyu.com/