系统环境`：CentOS 5.5（定制安装） 组件： Base Development Libraries Development Tools Editors Text-based Internet
lvs-master：192.168.9.201 lvs-backup：192.168.9.202 vip：192.168.9.200 web1：192.168.9.203 web2：192.168.9.204 netmask：255.255.255.0 gateway：192.168.9.1
网络拓扑：
echo "============================ 更新系统时间 ======================" yum install -y ntp ntpdate time.nist.gov echo "00 01 * * * /usr/sbin/ntpdate time.nist.gov" /etc/crontab
echo “============================ 关闭不用服务 =======================” /root/del_servcie.sh # 附件中自定义脚本
echo “========================= 安装ipvsadm、keepalived ==================” [root@master ~]# cd /usr/local/src [root@master ~]# wget [root@master ~]# wget [root@master ~]# ln -sv /usr/src/kernels/2.6.18-194.el5-i686/ /usr/src/linux [root@master ~]# tar -zxvf ipvsadm-1.24.tar.gz [root@master ~]# cd ipvsadm-1.24 [root@master ~]# make;make install [root@master ~]# cd .. [root@master ~]# tar -zxvf keepalived-1.1.17.tar.gz [root@master ~]# cd keepalived-1.1.17 [root@master ~]# ./configure configure: error: !!! OpenSSL is not properly installed on your system. !!! !!! Can not include OpenSSL headers files. 解决办法： [root@master ~]# yum -y install openssl-devel [root@master ~]# ./configure [root@master ~]# make;make install 编译的时候出现这个提示，说明keepalived和内核结合了，如果不是这样的，需要加上这个参数./configure --with-kernel-
dir=/kernel/path Keepalived configuration ------------------------ Keepalived version : 1.1.17 Compiler : gcc Compiler flags : -g -O2 Extra Lib : -lpopt -lssl -lcrypto Use IPVS Framework : Yes IPVS sync daemon support : Yes Use VRRP Framework : Yes Use LinkWatch : No Use Debug flags : No
echo “======================= 配置keepalived ===========================” [root@master ~]# cp /usr/local/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/ [root@master ~]# cp /usr/local/etc/sysconfig/keepalived /etc/sysconfig/ [root@master ~]# mkdir /etc/keepalived [root@master ~]# cp /usr/local/sbin/keepalived /usr/sbin/ [root@master ~]# vi /etc/keepalived/keepalived.conf ! Configuration File for keepalived global_defs { notification_email { } notification_email_from smtp_server smtp.163.com # smtp_connect_timeout 30 router_id LVS_DEVEL } # VIP1 vrrp_instance VI_1 { state MASTER #备份服务器上将MASTER改为BACKUP interface eth0 lvs_sync_daemon_inteface eth0 virtual_router_id 51 priority 100 # 备份服务上将100改为90 advert_int 5 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.9.200 #(如果有多个VIP，继续换行填写.) } } virtual_server 192.168.9.200 80 { delay_loop 6 #(每隔10秒查询realserver状态) lb_algo wlc #(lvs 算法) lb_kind DR #(Direct Route) persistence_timeout 60 #(同一IP的连接60秒内被分配到同一台realserver) protocol TCP #(用TCP协议检查realserver状态) real_server 192.168.9.203 80 { weight 100 #(权重) TCP_CHECK { connect_timeout 10 #(10秒无响应超时) nb_get_retry 3 delay_before_retry 3 connect_port 80 } } real_server 192.168.9.204 80 { weight 100 TCP_CHECK { connect_timeout 10 nb_get_retry 3 delay_before_retry 3 connect_port 80 } } } [root@master ~]# service keepalived start|stop [root@master ~]# chkconfig –level 2345 keepalived on
echo “====================== 配置realserver =========================” [root@web_1 ~]# vi /root/lvs_real.sh #!/bin/bash # description: Config realserver #Written by :
SNS_VIP=192.168.9.200 /etc/rc.d/init.d/functions case "$1" in start) /sbin/ifconfig lo:0 $SNS_VIP netmask 255.255.255.255 broadcast $SNS_VIP /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 sysctl -p >/dev/null 2>&1 echo "RealServer Start OK" ;; stop) /sbin/ifconfig lo:0 down /sbin/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
[root@web_1 ~]# chmod +x /roo/lvs_real.sh [root@web_1 ~]# /root/lvs_real.sh start
[root@web_1 ~]# ifconfig
[root@web_1 ~]# echo “/root/lvs_real.sh start” >> /etc/rc.local
echo “===================== 测试LVS+keepalived ========================” #LVS_master、LVS_backup上开启keepalived，LVS_master先绑定VIP LVS_master：
LVS_backup：
#解析域名，测试访问，LVS转发
#测试关闭LVS_master，短暂的掉包后，LVS_backup马上接替工作
LVS_backup接替LVS_master绑定VIP
LVS_backup负责转发
LVS_master重启完成后，就会自动接回控制权，继续负责转发
#测试关闭其中一台realserver
通过上面测试可以知道，当realserver故障或者无法提供服务时，负载均衡器通过健康检查自动把失效的机器从转发队列删除掉，
实现故障隔离，保证用户的访问不受影响
#重启被关闭的realserver
当realserver故障恢复后，负载均衡器通过健康检查自动把恢复后的机器添加到转发队列中