lvs+keepalived配置负载均衡

发牌SO

　　为了解决单点故障以及单台服务器的压力问题，在统一访问接口的同时，尽量将访问分发到多台web服务器，于是选择了LVS+Keepalived来实现负载均衡。
　　1、安装keepalived

apt-get install keepalived
　　2、修改 /etc/keepalived/keepalived.conf

! Configuration file for keepalived
global_defs {
notification_email {
penglin@jobcn.com
}
notification_email_from boss.web.balance@jobcn.com
smtp_server 192.168.60.131
smtp_connect_timeout 30
router_id LVS_DEVEL
}
#virtual_server_group BOSS_WEB_BALANCE {
#        192.168.60.200
#192.168.50.118
#192.168.60.119
#192.168.50.119
#}
vrrp_instance VI_1 {
state MASTER
interface eth1
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.60.201
#192.168.50.118
#192.168.60.119
#192.168.50.119
}
}
virtual_server 192.168.60.201 80 {
delay_loop 6
lb_algo rr
lb_kind DR
persistence_timeout 300
protocol TCP
real_server 192.168.60.119 80 {
weight 1
TCP_CHECK {
connect_timeout 10
nb_get_retry 3
delay_before_retry 3
connect_port 80
}
}
}
　　3、启动/终止 keepalived


/etc/init.d/keepalived start|stop
　　配置虚拟IP
　　创建realserver.sh，放在 /usr/local/test_sh/lvs/, 具备如下内容


#!/bin/bash
# Written by NetSeek
# description: Config realserver lo and apply noarp
WEB_VIP=192.168.60.118
case "$1" in
start)
ifconfig lo:0 $WEB_VIP netmask 255.255.255.255 broadcast $WEB_VIP
/sbin/route add -host $WEB_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)
ifconfig lo:0 down
route del $WEB_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"
;;
status)
# Status of LVS-DR real server.
islothere=`/sbin/ifconfig lo:0 | grep $WEB_VIP`
isrothere=`netstat -rn | grep "lo:0" | grep $web_VIP`
if [ ! "$islothere" -o ! "isrothere" ];then
# Either the route or the lo:0 device
# not found.
echo "LVS-DR real server Stopped."
else
echo "LVS-DR Running."
fi
;;
*)
# Invalid entry.
echo "$0: Usage: $0 {start|status|stop}"
exit 1
;;
esac
exit 0
　　启动/停止虚拟IP命令


cd /usr/local/boss_sh/lvs
./realserver.sh start|stop
　　讲解：使用LVS+Keepalived来实现负载均衡的配置的要点
　　1、最好配置热备，且使用两个虚拟IP,两台服务器相互为对方的备份，甚至可以使用3台Server来配置（为了更安全）
　　2、安装LVS尽量使用apt-get来安装，下载源码编译，不一定能成功
　　3、可以使用ipvsadm来查看LVS的状态
　　4、可以查看/var/log/message中的日志文件来了解LVS的状态
　　参考文档：http://wangyu.iteye.com/blog/424057
　　          http://linux.chinaunix.net/techdoc/net/2009/07/21/1125256.shtml