LVS+keepalived 安装配置

#LVS+keepalived 文档
VIP：192.168.95.135
机器1：192.168.95.130 既是direct server 也是realserver （安装软件：ipvsadm keepalived nginx）
机器2：1192.168.95.131 为realserver （安装软件：nginx）

机器1：
1. 安装ipvsadm：
cd /opt/soft
wget http://www.linuxvirtualserver.org/software/kernel-2.6/ipvsadm-1.24.tar.gz tar -zxvf ipvsadm-1.24.tar.gz
cd ipvsadm-1.24
make &&make install

以下对安装做一些验证：
1.先执行ipvsadm命令
2.lsmod |grep ip_vs
ip_vs_wlc 963 1
ip_vs 91193 3 ip_vs_wlc
ipv6 264702 15 ip_vs,ip6t_REJECT,nf_conntrack_ipv6

######################FAQ###################################
编译时候报 make[1]: *** [libipvs.o] Error 1 错误
解决方法：
#安装前要建立一个连接文件，否则会出错
ln -s /usr/src/kernels/2.6.9-42.EL-i686/ /usr/src/linux 一定要与当前的运行的内核相一致
#但是有时你找不到这个内核的路径，网上很多都是以上的解决方法连接，可有的系统安装完后并没有kernerls的目录
#解决方法：yum install kernel-devel、
############################################################

2. 安装keepalived
echo "1" > /proc/sys/net/ipv4/ip_forward
#install keepalived
yum -y install openssl-devel
cd /opt/soft
wget http://www.keepalived.org/software/keepalived-1.2.7.tar.gz tar zxvf keepalived-1.2.7.tar.gz
cd keepalived-1.2.7
./configure --prefix=/usr/local/keepalived
make
make install
cp /usr/local/keepalived/sbin/keepalived /usr/sbin/
cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
cp /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/init.d/
mkdir /etc/keepalived
cd /etc/keepalived/

3. 配置keepalived
#guration File for keepalived
#global define
global_defs {
router_id LVS_DEVEL
}

vrrp_sync_group VGM {
group {
VI_1
}
}

vrrp_instance VI_1 {
state MASTER
interface eth1
virtual_router_id 51
priority 180
advert_int 5
authentication {
auth_type PASS
auth_pass 1111
}

virtual_ipaddress {
192.168.95.135
}
}

# setting port 80 forward
virtual_server 192.168.95.135 80 {
delay_loop 6
lb_algo wlc
lb_kind DR
#persistence_timeout 20
protocol TCP

real_server 192.168.95.130 80 {
weight 100
TCP_CHECK {
connect_timeout 3
　nb_get_retry 3
　delay_before_retry 3
　connect_port 80
}
}

real_server 192.168.95.131 80 {
weight 100
TCP_CHECK {
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
connect_port 80
}
}
}

4. 编写lvs客户端配置脚本
[root@centos01 nginx]# cat /data/shell/lvs_real
#!/bin/bash
#description : start realserver
VIP=192.168.95.135
/etc/rc.d/init.d/functions

case "$1" in
start)
echo " start LVS of REALServer"
/sbin/ifconfig lo:0 $VIP broadcast $VIP netmask 255.255.255.255 up
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
;;
stop)
/sbin/ifconfig lo:0 down
echo "close LVS Directorserver"
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 "Usage: $0 {start|stop}"
exit 1
esac

机器2：
只需配置lvs客户端脚本
[root@centos01 nginx]# cat /data/shell/lvs_real
#!/bin/bash
#description : start realserver
VIP=192.168.95.135
/etc/rc.d/init.d/functions

case "$1" in
start)
echo " start LVS of REALServer"
/sbin/ifconfig lo:0 $VIP broadcast $VIP netmask 255.255.255.255 up
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
;;
stop)
/sbin/ifconfig lo:0 down
echo "close LVS Directorserver"
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 "Usage: $0 {start|stop}"
exit 1
esac

结果测试：
在机器1上： service keepalived start
两台机器上执行上述的lvs_real start
机器1上可看到lvs正常运行：
[root@centos01 nginx]# ipvsadm
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP swf.98poker.com:http wlc
-> 192.168.95.131:http Route 100 0 0
-> 192.168.95.130:http Local 100 0 0
执行ip addr 可看到vip已在eth1上

关闭机器2的nginx，可看到此时机器2已从realserver中剔除：
[root@centos01 nginx]# ipvsadm
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP swf.98poker.com:http wlc
-> 192.168.95.130:http Local 100 0 0
开启机器2的nginx服务，机器2又自动加入到realserver中。

此外，机器2也可像机器一样，既是direct server 又是realserver，作为机器1的backup，具体配置跟机器1差不多(global_defs的router_id，修改state为BACKUP，priority减小)

总结：只需在负载均衡机器上安装ipvsadm和keepalived，并执行keepalived启动。在real server机器上仅需开启本地回环地址（脚本）即可，不用安装任何软件。如果既是负载均衡机器有事real server就都安装。
本文出自 “运维人--hysen” 博客，请务必保留此出处http://hysen.blog.51cto.com/922448/1283362