实验：实践单主组KeeAlived和IPVS(LVS–DR模式)的双集群、高可用、健康性检查

一、前期规则设置
CIP：192.168.10.50 gateway:192.168.10.2
Route: 192.168.10.60 192.168.80.60 启用IP_forward的功能,不能有网关。
KA1：DIP:192.168.80.100 gateway:192.168.80.60 配置文件绑定VIP
KA2: RIP:192.168.80.110 gateway:192.168.80.60 配置文件绑定VIP
RS1: RIP:192.168.80.120 gateway:192.168.80.60 VIP: 192.168.80.222/32 VIP绑定在lo
RS2: RIP:192.168.80.130 gateway:192.168.80.60 VIP: 192.168.80.222/32 VIP绑定在lo
KA 其它配置准备：
(1) 各节点时间必须同步 ntp, chrony
(2) 确保iptables及selinux不会成为阻碍
(3) 各节点之间可通过主机名互相通信（对KA并非必须）建议使用/etc/hosts文件实现
(4) 各节点之间的root用户可以基于密钥认证的ssh服务完成互相通信（对KA并非必须）
(5)两台KA服务器文件对密钥对考(非必须) ssh-keygen ssh-copy-id KA_IP
(6)vim /etc/hosts (非必须) 192.168.80.100 KA1 192.168.80.110 KA2

二、KA服务器软件安装
yum install keepalived ipvsadm
yum install httpd #用于sorry server
测试页：
echo sorry_server ka1 > /var/www/html/index.html
echo sorry_server ka2 > /var/www/html/index.html

三、RS的服务器DR模式设置方法一：(手动)
echo 1 > /proc/sys/net/ipv4/conf/all/arp_ignore
echo 1 > /proc/sys/net/ipv4/conf/lo/arp_ignore
echo 2 > /proc/sys/net/ipv4/conf/all/arp_announce
echo 2 > /proc/sys/net/ipv4/conf/lo/arp_announce

RS服务器安装软件
yum install httpd
两台RS设置VIP地址
ip addr add 192.168.80.222/32 dev lo:1
测试页：
echo 192.168.80.120_index.html RS1 > /var/www/html/index.html
echo 192.168.80.130_index.html RS2 > /var/www/html/index.html
三、RS的服务器DR模式设置方法二 ：(脚本)
cat lvs_dr_rs.sh
#!/bin/bash
#Author:wangxiaochun
#Date:2017-08-13
vip=192.168.80.222
mask='255.255.255.255'
dev=lo:1
rpm -q httpd &> /dev/null || yum -y install httpd &>/dev/null
service httpd start &> /dev/null && echo "The httpd Server is Ready!"
echo "hostname" > /var/www/html/index.html
case 1 in
start)
echo 1 > /proc/sys/net/ipv4/conf/all/arp_ignore
echo 1 > /proc/sys/net/ipv4/conf/lo/arp_ignore
echo 2 > /proc/sys/net/ipv4/conf/all/arp_announce
echo 2 > /proc/sys/net/ipv4/conf/lo/arp_announce
ifconfig $dev $vip netmask $mask #broadcast $vip up
#route add -host $vip dev $dev
echo "The RS Server is Ready!"
;;
stop)
ifconfigdev down
echo 0 > /proc/sys/net/ipv4/conf/all/arp_ignore
echo 0 > /proc/sys/net/ipv4/conf/lo/arp_ignore
echo 0 > /proc/sys/net/ipv4/conf/all/arp_announce
echo 0 > /proc/sys/net/ipv4/conf/lo/arp_announce
echo "The RS Server is Canceled!"
;;
*)
echo "Usage: $(basename $0) start|stop"
exit 1
;;
esac
三、测试下访问两台RS是否能访问，IP绑定情况
curl 192.168.80.120
192.168.80.120_index.html RS1
curl 192.168.80.130
192.168.80.130_index.html RS2

四、KA服务器文件配置单主机模式的lvs集群

1.vim /etc/keepalived/keepalived.conf
global_defs {
notification_email {
root@localhost
}
notification_email_from 6m1@localhost
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id ka1
vrrp_mcast_group4 224.100.100.43
}
vrrp_instance zzhz {
state MASTER
interface eth0
virtual_router_id 51
priority 95
advert_int 2
authentication {
auth_type PASS
auth_pass centos
}
virtual_ipaddress {
192.168.80.222/24 dev eth0 label eth0:1 #这里的IP跟virtual_server同一个。
}
notify_master "/etc/keepalived/notify.sh master"
notify_backup "/etc/keepalived/notify.sh backup"
notify_fault "/etc/keepalived/notify.sh fault"
}
virtual_server 192.168.80.222 80 { ##这里的IP跟virtual_ipaddress 同一个。
delay_loop 6
lb_algo rr
lb_kind DR
protocol TCP
sorry_server 127.0.0.1 80

real_server 192.168.80.120 80 {
weight 1
HTTP_GET { #应用层检测 访问日志有日志
url {
path /
status_code 200
}
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
real_server 192.168.80.130 80 {
weight 1
TCP_CHECK { #另一台主机使用TCP检测 tcpdump -i eth0 -nn host 192.168.80.100
connect_ip 192.168.80.130
connect_port 80
bindto 192.168.80.100
bind_port 7777
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
}

五：另一台 KA2服务器文件配置单主机模式的lvs集群

global_defs {
notification_email {
root@localhost
}
notification_email_from keepalived@localhost
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id ka2
vrrp_mcast_group4 224.100.100.43
}
vrrp_instance zzhz {
state BACKUP
interface eth0
virtual_router_id 51
priority 85
advert_int 2
authentication {
auth_type PASS
auth_pass centos
}
virtual_ipaddress {
192.168.80.222/24 dev eth0 label eth0:1
}
notify_master "/etc/keepalived/notify.sh master"
notify_backup "/etc/keepalived/notify.sh backup"
notify_fault "/etc/keepalived/notify.sh fault"
}
virtual_server 192.168.80.222 80 {
delay_loop 6
lb_algo rr
lb_kind DR
protocol TCP
sorry_server 127.0.0.1 80
real_server 192.168.80.120 80 {
weight 1
HTTP_GET {
url {
path /
status_code 200
}
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
real_server 192.168.80.130 80 {
weight 1
TCP__CHECK {
　　connect_ip 192.168.80.130
　　　　　　connect_port 80
　　　　　　bindto 192.168.80.100
　　 bind_port 7777
　 connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
}

六、测试： RS故障

# while true ; do curl http://192.168.80.222 ;sleep 1; done
192.168.80.130_index.html RS2
192.168.80.120_index.html RS1 #正常
curl: (7) couldn't connect to host #130使用TCP_CHECK方法的，这里的断网测试, #TCP检测,使用systemctl stop httpd，ipvsadm -Ln的列表是不删除的，还是会调用。
192.168.80.120_index.html RS1
192.168.80.120_index.html RS1
curl: (7) couldn't connect to host #120 使用HTTP_CHECK方法,systemctl stop httpd
curl: (7) couldn't connect to host　　
sorry_server ka1
sorry_server ka1
[root@localhost7A ~]# ipvsadm -Ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port Forward Weight ActiveConn InActConn
TCP 192.168.80.222:80 rr
-> 127.0.0.1:80 Route 1 0 5
六、测试：KA故障
systemctl status keepalived.service
tcpdump -i eth0 -nn host 224.100.100.43