nginx+keepalived实现高可用负载均衡
本文介绍了nginx反向代理多虚拟主机节点服务器配合keepalived实现高可用和负载均衡，keepalived除了能够管理LVS软件外，还可以作为其他服务的高可用解决方案软件。采用 nginx+keepalived，它是一个高性能的服务器高可用或者热备解决方案，Keepalived主要来防止服务器 单点故障的发生问题，可以通过其与Nginx的配合实现Web服务器端的高可用。使用keepalived可以保 证nginx的高可用，他能监控nginx的健康状态，当nginx出现宕机时自动主备切换
配置有点像：基于keepalived实现haproxy高可用站点-CSDN博客
环境准备：
4台Linux Rocky8.10虚拟机，两台提供nginx的web服务器：192.168.118.131/129。本项目采用非keepalived的非抢占模式，两台keepalived的互为backup服务器：192.168.118.128/130
配置nginx服务器
下载：
yum install nginx -y
配置：vim /etc/nginx/conf.d/vhost.conf
server {
listen 80;
server_name bbs.test.com;
location /{
root /usr/share/nginx/html/bbs;
index index.html index.htm;
}
access_log /usr/share/nginx/html/bbs/logs/access_bbs.log main;
}
server {
listen 80;
server_name www.test.com;
location /{
root /usr/share/nginx/html/www;
index index.html index.htm;
}
access_log /usr/share/nginx/html/www/logs/access_www.log main;
}关闭selinux和防火墙：setenforce 0 && systemctl stop firewalld
在两台服务器上面执行以下命令：
mkdir -p /usr/share/nginx/html/{www,bbs}
touch /usr/share/nginx/html/www/index.html
touch /usr/share/nginx/html/bbs/index.html
echo "bbs: This is a test page which from: IP:$(hostname -I)" > /usr/share/nginx/html/bbs/index.html
echo "www: This is a test page which from: IP:$(hostname -I)" > /usr/share/nginx/html/www/index.html
touch /usr/share/nginx/html/bbs/logs/access_bbs.log
touch /usr/share/nginx/html/www/logs/access_www.log
chown -R nginx:nginx /usr/share/nginx/拓扑结构：
[root@localhost ~]# tree /usr/share/nginx/html/
/usr/share/nginx/html/
├── 404.html
├── 50x.html
├── bbs
│ ├── index.html
│ └── logs
│ └── access_bbs.log
├── index.html
├── nginx-logo.png
├── poweredby.png
└── www
├── index.html
└── logs
└── access_www.log
启动nginx：systemctl start nginx
测试
echo "192.168.118.129 www.test.com bbs.test.com" >> /etc/hosts[root@localhost conf.d]# curl www.test.com
www: This is a test page which from 192.168.118.129
[root@localhost conf.d]# curl bbs.test.com
bbs: This is a test page which from 192.168.118.129
配置nginx代理
vim /etc/nginx/conf.d/vtest.conf
upstream server_pools {
server 192.168.118.129:80 weight=1;
server 192.168.118.131:80 weight=1;
} server {
listen 80;
server_name www.test.com;
location / {
proxy_pass http://server_pools;
#传递原始的host头部信息
proxy_set_header Host $host;
}
} server {
listen 80;
server_name bbs.test.com;
location / {
proxy_pass http://server_pools;
#传递原始的host头部信息
proxy_set_header Host $host;
}
}在这段配置中，当请求的server_name匹配到bbs.test.com或者www.test.com时，location /会捕获所有对www.test.com或者bbs.test.com的请求，无论请求的URL是什么。这些请求都会被转发到上游服务器池server_pools中
然后在/etc/hosts中写入域名
#130主机
[root@localhost conf.d]# tail -1 /etc/hosts
192.168.118.130 www.test.com bbs.test.com
#128主机
[root@localhost conf.d]# tail -1 /etc/hosts
192.168.118.128 www.test.com bbs.test.com测试
[root@localhost ~]# for ((i=1;i<=4;i++));do curl www.test.com;done
www: This is a test page which from 192.168.118.129
www: This is a test page which from 192.168.118.131
www: This is a test page which from 192.168.118.129
www: This is a test page which from 192.168.118.131
[root@localhost ~]# for ((i=1;i<=4;i++));do curl bbs.test.com;done
bbs: This is a test page which from 192.168.118.129
bbs: This is a test page which from 192.168.118.131
bbs: This is a test page which from 192.168.118.129
bbs: This is a test page which from 192.168.118.131配置keepalived
vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
router_id LVS_1
}
vrrp_script chk_nginx {
script "killall -0 nginx"#检查是否开启了nginx代理
}
vrrp_instance VI_1 {
state BACKUP#备份模式
interface ens160
mcast_src_ip 192.168.118.130#基于这个源IP的健康检查
nopreempt#非抢占模式
virtual_router_id 51
priority 100#优先级
advert_int 1#间隔时间
authentication {#认证
auth_type PASS
auth_pass 1111
}
track_script {#调用脚本
chk_nginx
}
virtual_ipaddress {#VIP
192.168.118.110
}
}systemctl start keepalived
效果
单开两个进程去时刻检查日志：tail -f /var/log/messages
当拥有VIP的一方停止nginx服务时，立刻就会移除VIP，另一方获得VIP
当其恢复时,VIP也不会回到自己这台主机上面，减少主从交换频率，提高稳定性。这就是非抢占模式
最后测试是否依旧可以通过这个虚拟IP访问：curl -H表示携带head信息
以上访问被分流，且更具访问的URL到不同页面