将Nginx修补为ip_hash 4个八位字节而不是3个

The generic hash method: the server to which a request is sent is
determined from a user-defined key which may be a text,variable,or
their combination. For example,the key may be a source IP and port,
or URI:

upstream backend {
    hash $request_uri consistent;

    server backend1.example.com;
    server backend2.example.com;
}

https://www.nginx.com/resources/admin-guide/load-balancer/

那么如何使用hash方法从IPv4中使用4个八位字节？让我们来看看如何从嵌入式变量部分http://nginx.org/en/docs/http/ngx_http_core_module.html#variables获取客户端IP

$remote_addr client address

所以代码看起来像：

upstream backend {
    hash $remote_addr consistent;

    server backend1.example.com;
    server backend2.example.com;
}

更新：

如果看一下Stream模块(TCP代理),第一个例子显示了完全相同的方法：

upstream backend {
    hash $remote_addr consistent;

    server backend1.example.com:12345  weight=5;
    server backend2.example.com:12345;
    server unix:/tmp/backend3;
}

server {
    listen 12346;
    proxy_pass backend;
}