nginx 如何配置负载均衡

Question

有三台机器，ABC,
所有请求都给A,然后A转发给BC，由BC处理业务
假设域名是bla.com
在机器A上，http 模块内写以下配置，访问bla.com，访问到的是A默认页面

upstream bla.com {
        ip_hash;
        server 192.168.100.2;
        server 192.168.100.3;
}

怎么样才能让所有的请求都按 ip_hash 转发给B,C

Answer 1

https 负载均衡架构如图，与http区别不大

upstream mywebapp1 {
    server 10.130.227.11;
    server 10.130.227.22;
}
server {
    listen 80;
    listen 443 ssl;
    server_name example.com www.example.com;

    ssl on;
    ssl_certificate         /etc/nginx/ssl/example.com/server.crt;
    ssl_certificate_key     /etc/nginx/ssl/example.com/server.key;
    ssl_trusted_certificate /etc/nginx/ssl/example.com/ca-certs.pem;

    location / {
        proxy_pass http://mywebapp1;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
    }
}

Answer 2

你的意思是, 不想让A服务器承担流量了?

1. 在服务器A转发给后端时, 设置特殊的header

add_header HELLO Y;

1. B,C在发现有HELLO这个header时,立即返回302,让用户对B,C直接发起连接

if ($http_HELLO = 'Y'){
    rewrite ^ http://$server_addr:$server_port$request_uri? redirect;
}