keepalived高可用LVS与Nginx 推荐

一、Keepalived
keepalived前提准备见上文 --> Keepalived基础配置

二、keepalived高可用LVS
keepalived能够根据配置文件生成ipvs规则，同时可以对后端各RS做健康状态检测
1、实验清单
director1： node1 192.168.0.40
director2： Nginx 192.168.0.108
Vip：192.168.0.80
RS1（httpd）：192.168.0.100
RS2（httpd）：192.168.0.101

2、配置文件

[root@Nginx ~]# cd /etc/keepalived/
[root@Nginx keepalived]# vim keepalived.conf
! Configuration File for keepalived

global_defs {
notification_email {
root@localhost
}
notification_email_from kaadmin@localhost
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id LVS_DEVEL
}
vrrp_script chk_mt {
script "[[ -f /etc/keepalived/down ]] && exit 1 || exit 0"
interval 1
weight -2
}
vrrp_instance VI_1 {
state MASTER               #node1须修改为BACKUP
interface eth0
virtual_router_id 51
priority 100               #node1降低优先级
advert_int 1
authentication {
auth_type PASS
auth_pass 71988d704dcae985
}
virtual_ipaddress {
192.168.0.80/32
}
track_script {
chk_mt
}
notify_master "/etc/keepalived/notify.sh master"
notify_backup "/etc/keepalived/notify.sh backup"
notify_fault "/etc/keepalived/notify.sh fault"
}

virtual_server 192.168.0.80 80 {
delay_loop 6     #服务器轮询6次超时
lb_algo rr       #LVS调度算法
lb_kind DR       #LVS转发方法
nat_mask 255.255.255.0     #掩码
persistence_timeout 50     #长链接时间
protocol TCP               #tcp协议
ha_suspend                 #在无vip情形下，不再进行健康状态检测
sorry_server 127.0.0.1 80        #当RS全宕机时，sorry_server提供错误页面
real_server 192.168.0.100 80 {          #RS的ip，端口
weight 1                            #权重
HTTP_GET {                          #检测类型，这里是HTTP_GET
url {                           #检测请求的类型，这里是状态检测
path /
status_code 200
}
connect_timeout 3               #连接超时时间
nb_get_retry 3                  #重试次数
delay_before_retry 3            #重试前延迟时间
}
}
real_server 192.168.0.101 80 {
weight 2
HTTP_GET {
url {
path /
status_code 200
}
connect_timeout 3
nb_get_retry 3
delay_before_retry 3
}
}

}

3、定义状态转变后发邮件的notify脚本（来自马哥文档）

#!/bin/bash
#

vip=192.168.0.80
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

二、高可用Nginx
1、在Nginx主机上配置反向代理upstream

http区段配置
upstream nodeserver{
server 192.168.0.30;
server 192.168.0.40;
}
server区段配置
location / {
proxy_pass http://nodeserver; proxy_set_header Host    $host;
proxy_set_header X-Real-IP  $remote_addr;
add_header X-Cache $upstream_cache_status;
}

2、配置keepalived，加入如下配置

global_defs {
notification_email {
root@localhost
}
notification_email_from kaadmin@localhost
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id LVS_DEVEL
}
vrrp_script chk_nginx {
script "killall -0 nginx &> /dev/null"
interval 1
weight -10
}

vrrp_instance VI_1 {
state MASTER
interface eth0
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 71988d704dcae985
}
virtual_ipaddress {
192.168.0.80/32
}
track_script {
chk_nginx
}
notify_master "/etc/keepalived/notify.sh master"
notify_backup "/etc/keepalived/notify.sh backup"
notify_fault "/etc/keepalived/notify.sh fault"
}