What Nginx Can Do Without Third‑Party Modules: Reverse Proxy, Load Balancing, HTTP Server, and Forward Proxy

Preface

This article focuses on what Nginx can handle without loading third‑party modules; it may not be exhaustive, but it reflects the author’s personal experience.

What Nginx Can Do

1. Reverse proxy

2. Load balancing

3. HTTP server (including static‑dynamic separation)

4. Forward proxy

The following sections describe each function in detail.

Reverse Proxy

Reverse proxy is one of the most common uses of Nginx. It receives external requests and forwards them to internal servers, returning the response to the client.

Below is a simple reverse‑proxy configuration:

server {
    listen       80;
    server_name  localhost;
    client_max_body_size 1024M;

    location / {
        proxy_pass http://localhost:8080;
        proxy_set_header Host $host:$server_port;
    }
}

After saving the configuration and starting Nginx, accessing http://localhost will be proxied to http://localhost:8080 .

Load Balancing

Load balancing distributes requests across multiple backend servers. Nginx supports several built‑in strategies and two common third‑party ones.

1. RR (Round‑Robin, default)

Requests are distributed sequentially; unavailable servers are automatically removed.

Simple configuration:

upstream test {
    server localhost:8080;
    server localhost:8081;
}
server {
    listen 81;
    server_name localhost;
    client_max_body_size 1024M;
    location / {
        proxy_pass http://test;
        proxy_set_header Host $host:$server_port;
    }
}

The core of this configuration is the upstream block shown above.

2. Weight

Assigns a weight to each server; higher weight receives more requests.

upstream test {
    server localhost:8080 weight=9;
    server localhost:8081 weight=1;
}

In ten requests, roughly nine go to 8080 and one to 8081 .

3. ip_hash

Hashes the client IP so that a given client always reaches the same backend, useful for session‑based applications.

upstream test {
    ip_hash;
    server localhost:8080;
    server localhost:8081;
}

4. fair (third‑party)

Distributes requests based on backend response time; faster servers receive more traffic.

upstream backend {
    fair;
    server localhost:8080;
    server localhost:8081;
}

5. url_hash (third‑party)

Hashes the request URI, directing the same URL to the same backend, which is helpful for caching.

upstream backend {
    hash $request_uri;
    hash_method crc32;
    server localhost:8080;
    server localhost:8081;
}

Choose the strategy that best fits your scenario; note that fair and url_hash require third‑party modules.

HTTP Server

Nginx can serve static resources directly. A basic static‑file server configuration looks like this:

server {
    listen 80;
    server_name localhost;
    client_max_body_size 1024M;
    location / {
        root e:\wwwroot;
        index index.html;
    }
}

Visiting http://localhost will return e:\wwwroot\index.html . For dynamic sites, you can separate static and dynamic requests:

upstream test {
    server localhost:8080;
    server localhost:8081;
}
server {
    listen 80;
    server_name localhost;
    location / {
        root e:\wwwroot;
        index index.html;
    }
    location ~ \.(gif|jpg|jpeg|png|bmp|swf|css|js)$ {
        root e:\wwwroot;
    }
    location ~ \.(jsp|do)$ {
        proxy_pass http://test;
    }
    error_page 500 502 503 504 /50x.html;
    location = /50x.html {
        root e:\wwwroot;
    }
}

This setup serves static files directly while forwarding JSP/DO requests to a backend (e.g., Tomcat).

Forward Proxy

A forward proxy sits between the client and the origin server. Nginx can act as a forward proxy, though HTTPS support is limited.

resolver 114.114.114.114 8.8.8.8;
server {
    resolver_timeout 5s;
    listen 81;
    access_log e:\wwwroot\proxy.access.log;
    error_log e:\wwwroot\proxy.error.log;
    location / {
        proxy_pass http://$host$request_uri;
    }
}

Configure the DNS resolvers and the listening port, then configure your browser or proxy client to use IP:81 as the proxy.

Final Remarks

Nginx supports hot reload, allowing configuration changes without stopping the service. Reload commands are:

nginx -s reload

On Windows:

nginx.exe -s reload

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