LVS+Keepalived负载均衡集群之DR模式

一、环境

5台虚拟机，分别是：

1台测试机（192.168.3.111）;

2台DirectorServer（192.168.3.221、192.168.3.222）;

2台RealServer（192.168.3.231、192.168.3.232）;

注：VIP本实验设置为：192.168.3.220

二、安装配置RealServer

yum -y install httpd

chkconfig httpd on

echo ‘R1/R2‘ /var/www/html/index.html    #两台的配置都一样，这步为了区别访问的是哪台的数据，所以分为R1与R2，生产机上一般是统一访问后端的数据层的数据；

service httpd start

#!/bin/bash
SNS_VIP=192.168.3.220
. /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
sysctl -p >/dev/null 2>&1
echo "RealServer Stoped"
;;
*)
echo "Usage: $0 {start|stop}"
exit 1
esac
exit 0

复制以上内容丢到/etc/init.d/ 目录下，命名自定义，我是命名为:realserver.sh

chmod u+x /etc/init.d/realserver.sh

ln -s /etc/init.d/realserver.sh /etc/rc.d/rc3.d/S99realserver.sh    #设置开机自启动

三、安装配置DirectorServer

yum -y install gcc kernel-devel openssl-devel lrzsz vim ipvsadm

wget  http://www.keepalived.org/software/keepalived-1.2.15.tar.gz

tar xzvf keepalived-1.2.15.tar.gz

cd keepalived-1.2.15

./configure --sysconf=/etc/ --with-kernel-dir=/usr/src/kernels/2.6.32-504.23.4.el6.x86_64/

make

make install

ln -s /usr/local/sbin/keepalived /sbin/

cd /etc/keepalived/

cp keepalived.conf keepalived.conf.bak

编辑keepalived.conf，内容大致如下:

! Configuration File for keepalived
global_defs {
   notification_email {
     [email protected]
   }
   notification_email_from [email protected]
   smtp_server 192.168.200.1
   smtp_connect_timeout 30
   router_id LVS_DEVEL
}
vrrp_instance VI_1 {
    state MASTER
    interface eth0
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.3.220
    }
}
virtual_server 192.168.3.220 80 {
    delay_loop 6
    lb_algo wlc
    lb_kind DR
    nat_mask 255.255.255.0
    persistence_timeout 50
    protocol TCP
    real_server 192.168.3.231 80 {
        weight 2
        TCP_CHECK {
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
            connect_port 80
        }
    }
    real_server 192.168.3.232 80 {
        weight 1
        TCP_CHECK {
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
            connect_port 80
        }
    }
}

注：第二台DS服务器（备）需要更改以上两处的内容，一是把MASTER更改为BACKUP，二是把优先级由100改为80即可；

四、校验及测试

4.1、ipvsadm -L -n #正常显示VIP及RIP等内容；

4.2、ip addr list #主服务器正常显示VIP,备服务器没有VIP；

4.3、把主服务器关机，看备服务器会不会把服务接管过来；