LVS + keepalived 实现负载均衡

1. 下载相关软件包

#mkdir /usr/local/src/lvs
#cd /usr/local/src/lvs
#wget http://www.linuxvirtualserver.org/software/kernel-2.6/ipvsadm-1.24.tar.gz
#wget http://www.keepalived.org/software/keepalived-1.1.15.tar.gz
2. 安装LVS和Keepalived

#lsmod |grep ip_vs
#uname -r
2.6.18-53.el5PAE
需要安装 ：
yum install -y kernel-devel
#ln -s /usr/src/kernels/2.6.18-53.el5PAE-i686/ /usr/src/linux

#tar zxvf ipvsadm-1.24.tar.gz
#cd ipvsadm-1.24
#make && make install
#find / -name ipvsadm # 查看ipvsadm的位置
#tar zxvf keepalived-1.1.15.tar.gz
需要安装 ：

yum -y install openssl-devel

#cd keepalived-1.1.15
#./configure && make && make install
#find / -name keepalived # 查看keepalived位置
#cp /usr/local/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/
#cp /usr/local/etc/sysconfig/keepalived /etc/sysconfig/
#mkdir -p /etc/keepalived
#cp /usr/local/etc/keepalived/keepalived.conf /etc/keepalived/
#cp /usr/local/sbin/keepalived /usr/sbin/
#service keepalived start|stop #做成系统启动服务方便管理.
3. 配置Realserver脚本.
#vi /usr/local/sbin/realserver.sh
#!/bin/bash
# description: Config realserver lo and apply noarp
#Written by :NetSeek http://www.linuxtone.org

SNS_VIP=192.168.1.163

. /etc/rc.d/init.d/functions

case "$1" in
start)
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)
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
4. 配置在主负载均衡服务器上配置keepalived.conf
vi /etc/keepalived/keepalived.conf

! Configuration File for keepalived
global_defs {
notification_email {
[e-mail]
}
notification_email_from [e-mail]
smtp_server 127.0.0.1
# smtp_connect_timeout 30
router_id LVS_DEVEL
}
# 20081013 written by :netseek
# VIP1
vrrp_instance VI_1 {
state MASTER #备份服务器上将MASTER改为BACKUP
interface eth0
virtual_router_id 51
priority 100 # 备份服务上将100改为99
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
61.164.122.8
#(如果有多个VIP，继续换行填写.)
}
}
virtual_server 61.164.122.8 80 {
delay_loop 6 #(每隔10秒查询realserver状态)
lb_algo wrr #(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 61.164.122.9 80 {
weight 3 #(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 61.164.122.10 80 {
weight 3
TCP_CHECK {
connect_timeout 10
nb_get_retry 3
delay_before_retry 3
connect_port 80
}
}
}


5. BACKUP服务器同上配置，先安装lvs再按装keepalived,仍后配置/etc/keepalived/keepalived.conf，
只需将标示的部分改一下即可.


6.
#/etc/init.d/keepalived start 启动keepalived服务，keepalived就能利用keepalived.conf 配置文件，实现负载均衡和高可用.
查看lvs服务是否正常
#watch ipvsadm -ln

停Master服务器的keepalived服务，查看BAKCUP服务器是否能正常接管服务