nginx+keepalived实现高可用集群

实验环境：

两台调度器，一主一备

192.168.200.111

192.168.200.112

两台web服务器

192.168.200.113

192.168.200.114

利用keepalived实现主备的故障切换，从而交替提供服务

利用nginx实现负载均衡的调度

配置主调度器：

1.安装依赖包

yum -y instsall ipvsadm keepalived

2.将配置文件进行备份，避免出错

cd /etc/keepalived

cp keepalived.conf keepalived.con.bak

3.编辑配置文件

vim keepalived.conf

#全局配置

! Configuration File for keepalived

global_defs {
   notification_email {
     acassen@firewall.loc
     failover@firewall.loc
     sysadmin@firewall.loc
   }
   notification_email_from Alexandre.Cassen@firewall.loc
   smtp_server 192.168.200.1
   smtp_connect_timeout 30
   router_id LVS_MASTER
}

 #基于nginx脚本实现调度

vrrp_script check_nginx {
script "/opt/chk_nginx.sh"
interval 2
weight -20
}

 

#调度配置

vrrp_instance VI_1 {
state MASTER
interface eno16777728
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 1111
}
virtual_ipaddress {
192.168.200.254
}
track_script {
check_nginx #引用nginx脚本
}
}

 

4.安装nginx服务

（1.）源码安装，参考nginx安装的博客文章

（2.）软件包安装，参考fpm制作rpm包的博客文章

5.修改nginx配置文件

vim /usr/local/nginx/conf/nginx.conf

红色字体添加内容：

keepalive_timeout 65;
upstream httpd_server {
server 192.168.200.113 weight=1;
server 192.168.200.114 weight=1;
}
server {
listen 80;
server_name localhost;
charset utf-8;

location / {
root html;
index index.html index.htm;
proxy_pass http://httpd_server;
proxy_set_header Host $http_host;
}

6.配置完成后启动服务

systemctl start keepalived 

7.查看VIP端口

ip a

8.查看调度服务

ipvsadm  -Ln

9.将主配置文件发送给备调度器，修改相应内容

scp /etc/keepalived/keepalived.conf 192.168.200.112:/etc/keepalived/

10.编辑nginx脚本文件，配置为周期性任务

mkdir /shell

vim /shell/nginx_check.sh

编辑内容：

#!/bin/bash
count="$(ps -C nginx --no-header|wc -l)"

if [ $count -eq 0 ];then
nginx
sleep 2
if [ `ps -c nginx --no-header` |wc -l -eq 0 ];then
systemctl stop keepalived
fi
fi

11.给脚本添加执行权限

chmod +x /shell/nginx_check.sh

配置节点服务器：

1.安装apache服务

yum -y install httpd

2.添加路由

ifconfig lo:0 192.168.200.254 netmask 255.255.255.255

route  add -host 192.168.200.254 dev lo:0

3.创建测试网页

echo "11111" > /var/www/html/index.html

4.启动apache服务

systemctl start httpd

5.修改配置文件

vim /etc/sysctl.conf

添加内容;

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

6.加载配置信息

sysctl -p

##每台节点服务器都要进行相同的配置

实验测试：

1.关闭所有服务器的防火墙和Linux安全机制

iptables -F

systemctl stop firewalld

setenforce 0

2.在浏览器中输入虚拟服务器的IP地址

这里我们用的是192.168.200.254

 

实现轮询的结果

3.关掉nginx和keepalived进行高可用测试

killall -9 nginx
systemctl stop keepalived

while :
> do
> curl 192.168.200.254
> sleep 1
> done

进行测试。