项目实战3—Keepalived实现高可用

① 全局段，故障通知邮件配置
global_defs {
notification_email {
root@localhost
}
notification_email_from root@along.com
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id keepalived_lvs
}
② 配置虚拟路由器的实例段，VI_1是自定义的实例名称，可以有多个实例段
vrrp_instance VI_1 { 　#VI_1是自定义的实例名称
state MASTER 　　 　 #初始状态，MASTER|BACKUP
interface eth1 　　 　 #通告选举所用端口
virtual_router_id 51 #虚拟路由的ID号（一般不可大于255）
priority 100 　　　　　#优先级信息 #备节点必须更低
advert_int 1 　　　　　#VRRP通告间隔，秒
authentication {
auth_type PASS #认证机制
auth_pass along #密码（尽量使用随机）
}
virtual_ipaddress {
172.17.100.100 　#vip
}
}
③ 设置一个virtual server段
virtual_server 172.17.100.100 80 { #设置一个virtual server:
delay_loop 6 # service polling的delay时间，即服务轮询的时间间隔
lb_algo wrr　　　 #LVS调度算法：rr|wrr|lc|wlc|lblc|sh|dh
lb_kind DR　　　　#LVS集群模式：NAT|DR|TUN
nat_mask 255.255.255.255
persistence_timeout 600 #会话保持时间（持久连接，秒），即以用户在600秒内被分配到同一个后端realserver
protocol TCP 　#健康检查用的是TCP还是UDP

④ real server设置段
real_server 172.17.1.7 80 { #后端真实节点主机的权重等设置
weight 1 #给每台的权重，rr无效
HTTP_GET { #http服务
url {
path /
}
connect_timeout 3 #连接超时时间
nb_get_retry 3　　 #重连次数
delay_before_retry 3 #重连间隔
}
}
real_server 172.17.22.22 80 {
weight 2
HTTP_GET {
url {
path /
}
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
}

vrrp_instance VI_1 {
state BACKUP
interface eth1
virtual_router_id 51
priority 99
advert_int 1
authentication {
auth_type PASS
auth_pass along
}

net.ipv4.conf.lo.arp_ignore = 1
net.ipv4.conf.lo.arp_announce = 2
net.ipv4.conf.all.arp_ignore = 1
net.ipv4.conf.all.arp_announce = 2

vrrp_instance VI_1 {
state MASTER
interface eth1
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass along
}
virtual_ipaddress {
172.17.100.100
}
}
virtual_server 172.17.100.100 80 {
delay_loop 6
lb_algo wrr
lb_kind DR
nat_mask 255.255.255.255
persistence_timeout 600
protocol TCP
real_server 172.17.1.7 80 {
weight 1
HTTP_GET {
url {
path /
}
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
real_server 172.17.22.22 80 {
weight 1
HTTP_GET {
url {
path /
}
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
}

vrrp_instance VI_2 {
state BACKUP
interface eth1
virtual_router_id 52
priority 98
advert_int 1
authentication {
auth_type PASS
auth_pass along
}
virtual_ipaddress {
172.17.100.101
}
}
virtual_server 172.17.100.101 443 {
delay_loop 6
lb_algo wrr
lb_kind DR
nat_mask 255.255.255.255
persistence_timeout 600
protocol TCP
real_server 172.17.1.7 443 {
weight 1
HTTP_GET {
url {
path /
}
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
real_server 172.17.22.22 443 {
weight 1
HTTP_GET {
url {
path /
}
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
}

① vrrp_instance VI_1 {
state BACKUP
interface eth1
virtual_router_id 51
priority 98
advert_int 1
authentication {
auth_type PASS
auth_pass along
}
virtual_ipaddress {
172.17.100.100
}
}
② vrrp_instance VI_2 {
state MASTER
interface eth1
virtual_router_id 52
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass along
}
virtual_ipaddress {
172.17.100.101
}
}

global_defs {
notification_email {
root@localhost
}
notification_email_from root@along.com
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id keepalived_lvs
}
vrrp_instance VI_1 {
state MASTER
interface eth0
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass along
}
virtual_ipaddress {
172.17.100.100
192.168.30.100
}
}
virtual_server 172.17.100.100 80 {
delay_loop 6
lb_algo wrr
lb_kind NAT
nat_mask 255.255.255.255
persistence_timeout 100
protocol TCP
real_server 192.168.30.107 80 {
weight 1
HTTP_GET {
url {
path /
}
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
real_server 192.168.30.7 80 {
weight 2
HTTP_GET {
url {
path /
}
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}
}

vrrp_instance VI_1 {
state BACKUP
interface eth1
virtual_router_id 51
priority 99
advert_int 1
authentication {
auth_type PASS
auth_pass along
}

#!/bin/bash
# Author: www.magedu.com
contact=‘root@localhost‘
notify() {
mailsubject="$(hostname) to be $1: vip floating"
mailbody="$(date +‘%F %H:%M:%S‘): vrrp transition, $(hostname) changed to be $1"
echo $mailbody | mail -s "$mailsubject" $contact
}
case $1 in
master)
notify master
exit 0
;;
backup)
notify backup
exit 0
;;
fault)
notify fault
exit 0
;;
*)
echo "Usage: $(basename $0) {master|backup|fault}"
exit 1
;;
esac

notify_backup "/etc/keepalived/notify.sh backup"
notify_master "/etc/keepalived/notify.sh master"
notify_fault "/etc/keepalived/notify.sh fault"

vrrp_script chk_down { #定义一个脚本，脚本名称为chk_down
　　script "[[ -f /etc/keepalived/down ]] && exit 1 || exit 0" #检查这个down文件，若存在返回值为1，keepalived会停止；不存在返回值为0，服务正常运行；这里的exit和bash脚本里的return很相似
interval 2 #每2秒检查一次
}

track_script {
chk_down
}

vrrp_script chk_nginx {
script "killall -0 nginx" #killall -0 检测这个进程是否还活着，不存在就减权重
interval 2 #每2秒检查一次
fall 2 #失败2次就打上ko的标记
rise 2 #成功2次就打上ok的标记
weight -4 #权重，优先级-4，若为ko
}

track_script {
chk_nginx
}