Part 8: Nginx Gateway: How It Delivers Your Requests to Backend for Processing

Last updated: September 4th 2023


Last time, I illustrated setting up SSL with NGINX as a part of my "Introduction to Web Server Setup & Management" series. This series aims to help you thoroughly understand how web servers function and interact with their users. By the end of it, you'll have the skills to optimize your web server for an excellent user experience. Moreover, the knowledge you'll gain from this series transcends various programming languages and environments. It's a valuable addition to your skill set, and I'm confident you'll find it helpful. You’ll also understand why Webdock has built the things it offers.

And in this part, we will explore NGINX's role as a request relay in more detail. We will examine the benefits of using NGINX as a reverse proxy and how it can enhance the performance and scalability of web applications. Additionally, we will delve into the various configuration options available for NGINX, including setting up multiple upstream servers, load balancing algorithms, and SSL termination.

Whether you are a developer, system administrator, or IT manager, understanding NGINX's role as a request relay is essential for optimizing your web application's performance and security. Let's get into this.

What is an NGINX gateway/proxy?

In the world of web servers, NGINX has emerged as a popular choice for its high-performance capabilities and flexibility. One of the critical advantages of NGINX is its ability to serve as a request relay to backend applications. NGINX is a powerful web server that can be a gateway or proxy. A gateway/proxy is an intermediary server that sits between a client and a server, forwarding client requests to the server and returning its response back to the client.

NGINX gateway/proxy can be used in various ways, such as load balancing, caching, SSL termination, and reverse proxying. It can handle many requests efficiently, making it an excellent choice for high-traffic websites and applications.

Advantages of using NGINX as a reverse proxy

As a reverse proxy, NGINX packs a powerful punch, making it an invaluable tool for any savvy developer. Let's take a closer look at some of the perks you can expect when using NGINX in this capacity.

  • Performance: NGINX is a web server that can help speed up web applications by storing frequently accessed content, distributing requests among multiple servers, and ensuring that dynamic content is delivered as quickly as possible. Using NGINX, your web application can run smoothly and efficiently, meaning your users can enjoy a seamless user experience.
  • Security: NGINX can play an important role in safeguarding web applications against malicious attacks by screening incoming traffic, implementing strict security protocols, and keeping the identity of backend servers anonymous. These measures help to ensure the privacy and security of sensitive data and prevent unauthorized access to your web applications.
  • Scalability: NGINX can expand or contract as needed to meet the dynamic demands of web applications, making it incredibly adaptable and flexible.
  • Features: NGINX can help with HTTP/2, Gzip compression, and SSL/TLS encryption. These are just a few examples of the many features that NGINX brings.

How does NGINX work as a Proxy/Gateway?

Nginx is like a traffic controller standing in the middle of the road, directing cars to their desired destinations. It's a reverse proxy and load balancer, so it sits between the client and the backend server. Whenever a client makes a request to Nginx, it first checks if it can handle the request on its own. If Nginx is capable of handling the request, it'll serve the file directly from its file system, just like a pro. But if it's not up to the task, it'll gracefully hand over the request to the backend server.

When setting up your server, it's important to tell Nginx where to send requests for specific types of files. The proxy_pass directive is used to specify the backend server's URL and protocol. For instance, if you want Nginx to pass all requests for PHP files to a PHP-FPM server running on port 9000, you can configure it accordingly:

location ~ \.php$ {



Whenever a client requests a PHP file, Nginx reads and examines it before dispatching it to the PHP-FPM server. Following this, the PHP-FPM server processes the request before forwarding the response to Nginx. Nginx then relays the response to the client seamlessly.

This mechanism effectively positions Nginx as an intermediary between the client and the backend server. The beauty of this approach is that Nginx can delegate the processing of specific requests to the backend server, enhancing the system's overall performance.

When dealing with PHP files, Nginx can transfer requests to PHP-FPM, a process manager specializing in handling PHP requests. PHP-FPM then assesses the request and sends the appropriate response back to Nginx.

Moreover, you can use the proxy_pass directive to define a proxy upstream - a band of backend servers capable of handling similar requests. This feature comes in handy when distributing the load of requests across multiple servers is required.

If you want to make Nginx pass requests for PHP files to a PHP-FPM server, you can use the following configuration as an example:

server {

  listen 80;

  location / {

    root /var/www/html;

  location ~ \.php$ {




Here's a more straightforward way to put it: Nginx is set up to handle static files directly from its file system, but if you need to handle PHP files, it will send those requests to the PHP-FPM server on port 9000.

What is the difference between a Proxy and Gateway?

You might come across a proxy or a gateway when trying to connect to a server. These mediators help you communicate with the server, but they each have unique jobs and perks. So, while they seem similar at first glance, they serve different purposes and come with additional features to help you get the most out of your connection.

A Proxy is an intermediary server that forwards client requests to other servers. It acts as a go-between for clients and servers and can be used for various purposes, such as caching, filtering, and load balancing. Proxies can be set up at the application layer (e.g., HTTP proxies) or network layer (e.g., SOCKS proxies).

On the other hand, a Gateway is a server that acts as an entry point into a network or system. It can connect different types of networks or protocols and translate between them if necessary. Gateways can also be used for security purposes, such as filtering incoming traffic or providing a secure connection to an external network.

Usually, a proxy is the way to go when trying to make your internet experience faster, safer, or more private. It's a straightforward tool that gets the job done. In contrast, a gateway is a different beast - a more advanced tool to link various networks or offer extra network services.


In conclusion, NGINX's role as a request relay to backend applications is crucial to modern web development and deployment. As we've seen, NGINX's powerful and flexible configuration options and ability to scale horizontally make it an ideal choice for managing and optimizing web traffic. While other options are available, NGINX's popularity and proven track record make it a reliable choice for developers and sysadmins. So, whether you're just starting or looking to optimize your existing web infrastructure, NGINX is worth exploring.

Aayush Nair has been designing WordPress websites for eight years now. He is also a content writer, writing blogs on technology and related topics, and likes helping people in his free time.

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