Understanding Nginx: What Is Nginx and How Does Nginx Work?

Introduction

Nginx is an open-source and popular web server that plays a crucial role in delivering content and services to users across the globe. Known for its high performance, stability, and rich feature set, Nginx stands out among the many web servers available. Understanding what Nginx is and why web servers are essential can help you make informed decisions for your web infrastructure. In this overview, we’ll explore the basics of Nginx and highlight the importance of web servers in modern web development.

What is Nginx?

The open-source web server Nginx, which is also know as “engine-x,” serves as an HTTP cache, load balancer, and reverse proxy. Nginx, developed by Igor Sysoev and published in 2004, is well known for its robustness, minimal resource usage, broad feature set, and excellent performance.  These attributes have made Nginx one of the most popular web servers in the world.

Nginx acts as an intermediary between users and backend servers. It responds to user queries, processes them as necessary, and then sends them to the relevant backend servers for additional handling. And The response is sent back to the users by Nginx once it has been generated by the backend servers. This efficient management of the communication flow between the client and the server helps optimize performance, enhance security, and ensure efficient load balancing across servers.

For instance, when a user visits a website, their browser sends a request to Nginx. This request is processed by Nginx, which then chooses which backend server—such as a database or web application server—should handle it and sends it to that server. Once the backend server processes the request and generates a response, Nginx receives the response and sends it back to the user’s browser.

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Key Features of Nginx

Nginx is widely appreciated for its high performance, stability, and versatile functionality. Here are some of its key features:

1. High Performance

• Event-Driven Architecture: Efficiently handles a large number of concurrent connections using an event-driven, asynchronous architecture.
• Low Resource Consumption: Due to its efficient architecture, Nginx consumes fewer resources compared to other web servers, making it suitable for environments where resource efficiency is crucial, such as high-traffic websites and applications.

2. Reverse Proxy:

• Request Forwarding: As a reverse proxy, Nginx sits between clients (users’ browsers) and backend servers. It receives client requests and forwards them to the appropriate backend server based on predefined rules or algorithms. This allows Nginx to distribute incoming traffic across multiple servers, improving overall performance and reliability by reducing the workload on individual servers.

3. Load Balancing:

• The process of distributing incoming network traffic across multiple servers to ensure no single server becomes overwhelmed with too much traffic. This helps to enhance the performance, reliability, and availability of your web services.
• Nginx regularly assesses the backend servers’ health via health checks. Nginx automatically ceases sending requests to a server that becomes inaccessible or unhealthy (for example, because of a heavy load or network problems) until the server recovers, guaranteeing users continuous service.

4. SSL/TLS Termination:

• Encryption Handling: Nginx acts as an SSL/TLS termination point, handling encryption and decryption of HTTPS traffic. By offloading SSL/TLS processing from backend servers, Nginx improves server performance and reduces computational overhead. This is especially beneficial in environments with high security requirements or where secure communication is essential.

5. URL Rewriting and Redirection:

• Nginx provides powerful tools for rewriting and redirecting URLs based on predefined rules or conditions. Administrators can configure Nginx to redirect incoming requests to different URLs or rewrite URLs to meet specific application requirements

The NGINX Architecture

The main components of NGINX architecture include:

• Master

• Workers
• Cache

Let us have a brief description of the Nginx parts.

1. Master

As previously mentioned, Nginx uses a master-slave architecture where the master process assigns tasks to worker processes based on client requests. After assigning a task to a worker, the master immediately proceeds to handle the next client request without waiting for the worker’s response. Once a worker completes its task and sends back a response, the master forwards this response to the client. This design allows nginx to efficiently manage multiple client requests concurrently without delay.

2. Workers

In NGINX architecture, workers act as subordinate processes to the master. Each worker is capable of concurrently handling over 1000 requests in a single-threaded fashion. Upon completing a task, the worker sends the response back to the master. This single-threaded approach optimizes RAM and ROM usage by operating within the same memory space, unlike multi-threaded processes that operate across different memory spaces.

3. Cache

Page rendering is accelerated by NGINX caching, which retrieves saved pages from cache memory rather than the server. Pages are cached upon their initial request, enhancing response times for subsequent page views.

Setting Up Nginx

Here, we will guide you on how to install NGINX on Ubuntu OS. If you want to learn how to download NGINX on other operating systems like Windows or macOS, please visit the official website.

Step 1 – Installing Nginx

Open your terminal and update the repository using the `apt update` command.

# sudo apt update

And install the nginx 

# sudo apt install nginx

Step 2 – Adjusting the Firewall

Before testing Nginx, adjust the firewall software to allow access to the service. Once installed, Nginx registers itself as a service with ufw, making it simple to grant Nginx access.

Type the following to get a list of the application settings that ufw is familiar with:

# sudo ufw app list

Now you will receive a list of application profiles:

• Nginx Full: It opens both port 80 and port 443.
• Nginx HTTP: Opens only  normally and unencrypted web traffic of port 80 
• Nginx HTTPS: Only port 443 TLS/SSL encrypted communication.

Enabling the most restrictive profile that permits the traffic you have configured is advised. Traffic must now only be permitted on Port 80.

You can enable this by typing:

# sudo ufw allow ‘Nginx HTTP’

You can verify the change by typing:

#  sudo ufw status

The output will indicated which HTTP traffic is allowed:

Step 3 – Checking your Web Server

At the end of the installation process, Ubuntu 20.04 starts Nginx automatically andthe server might start running. 

To verify that the service is running using the systemd init system, type:

# systemctl status nginx

If nginx is not running or inactive you should run the nginx service by using below commands

# systemctl start nginx

To re-enable the service, type the following command; 

# systemctl enable nginx

Into the browser address bar, type your server’s IP address (if available), 

 http://<your_server_ip>

If your installation was successful it will display like below

This is just the installation process. If you want to deploy a website on your server, you’ll need to configure the NGINX files.

Advantages of NGINX

• This reduces the waiting time for website loading. You no longer need to concern yourself with high latency on your websites, thus ensuring a positive user experience.

• This feature accelerates performance by directing traffic to web servers in a manner that enhances overall speed. Consequently, it delivers a seamless browsing experience to your users.

• Serves as a cost-effective and resilient load balancer.

• Provides scalability and adeptly manages concurrent requests.

• Enables seamless upgrades without any downtime.

• High Performance

• Reverse Proxy

• Load Balancing

Disadvantages of NGINX

• Complex Configuration: Setting up NGINX for specific use cases can require advanced knowledge of its configuration syntax and server architecture, which may be challenging for beginners.

• Learning Curve: Mastering NGINX’s advanced features and optimizing its performance may require time and effort, especially compared to simpler web server solutions.

• Limited Built-in Functionality: Unlike some all-in-one web servers, NGINX focuses primarily on web serving, proxying, and load balancing. Additional features such as comprehensive GUIs or built-in support for specific applications may require third-party modules or customization.

• Resource Intensive Tasks: While NGINX is efficient with basic web serving tasks, handling complex dynamic content processing (e.g., extensive server-side scripting) may not be as straightforward without additional modules or configurations.

• Support and Documentation: While NGINX has a strong community and active development, troubleshooting advanced issues or finding specific configuration details may require deeper expertise or community support.

• SSL/TLS Configuration: Although NGINX supports SSL/TLS termination, configuring and managing SSL certificates and encryption settings can be complex, especially in environments requiring strict security compliance.

• Updates and Compatibility: Updating NGINX to newer versions or ensuring compatibility with other software components (e.g., operating systems, application frameworks) may require careful planning and testing to avoid disruptions.

• Lack of Integrated Development Environment (IDE): Unlike some integrated web server solutions, NGINX typically relies on command-line interfaces and configuration files, which may not provide the same level of visual feedback and ease of use for developers accustomed to IDEs.

Conclusion

In conclusion, NGINX stands as a versatile and powerful solution for various server needs, offering functionalities ranging from web serving to load balancing and beyond. Its efficient handling of web traffic, scalability, and robust performance make it a popular choice for websites and applications worldwide. However, challenges such as resource utilization optimization and error resolution persist and require careful monitoring and management. Overall, NGINX continues to play a crucial role in enhancing the reliability, speed, and security of web servers, contributing significantly to the seamless operation of online platforms and services