Network Gateways: Load Balancers, Proxies, and API Gateways

What are network Gateways?

Network gateways are crucial components in modern web architectures, acting as intermediaries between clients and servers. They help manage traffic, enhance security, and improve performance.

This article aims to explore four key concepts:

→ Load Balancers, Reverse Proxies, Forward Proxies, and API Gateways.

Whether you're looking to improve your skills as an engineer or simply want to gain a deeper perspective for the magic that happens behind the scenes, I hope to provide a clear and concise introduction to these fascinating concepts

1. Load Balancer

A load balancer distributes incoming network traffic across multiple servers.

• Improves the availability, reduces latency of an application

• Prevents Server Overload

• Supports various distribution algorithms ( e.g: round-robin, least-connections etc)

Example: Imagine a popular e-commerce website during a flash sale. The load balancer would distribute incoming customer requests across multiple web servers, preventing any single server from becoming overloaded with the requests and ensuring a smooth shopping experience for all users.

2. Reverse Proxy

A reverse proxy sits in front of web servers and forwards client requests to those web servers, providing an additional level of abstraction and control.

Usecases:

• Content Delivery Networks ( CDNs)

• Microservices and webapplications with muliple servers

Example: Imagine a company with many websites, each hosted on different servers. A Reverse Proxy acts as a traffic police that directs users to the right website based on what they're looking for. This setup simplifies the user experience and adds a layer of security by hiding the internal server structure.

3. Forward Proxy

Forward proxy, often called just "proxy," is a layer between the User and the Internet. It can be used for various purposes such as anonymity, caching, or content filtering.

Example: If you are using an office laptop in corporate network, a forward proxy might been used to block access to certain websites, cache frequently accessed content to save bandwidth, and provide anonymity for the internal network when accessing external resources.

4. API Gateway

An API Gateway acts as a single entry point for a group of microservices, handling tasks such as request routing, protocol translation etc.

Lets use the famous example of waiters in a hotel, there are many waiters running around taking orders from customers. They all have to get/take their orders to the same person in the kitchen, right? Well, an API Gateway is like that one person in the kitchen who receives all the orders from all the different waiters. It's a single point of connection where multiple things can come together and be processed.

Let's say you're shopping online at an e-commerce website, there are many features on the website like “add to cart”, “show item”, “sort items”, “give a rating” etc. You click on "Add to Cart" or "Show Item Details". Behind the scenes, your request is routed through the API Gateway to the relevant API or microservice that handles that specific action. The API Gateway ensures that all incoming requests are properly authenticated and authorized before they reach their final destination

Comparison

✅ - Primary feature, ⚠️ - Possible but not primary, ❌ - Not typically a feature

Complete Overview:

• Load Balancers focus on distributing traffic for performance and availability.

• Forward Proxies intercept outgoing requests from clients for various purposes like anonymity or content control.

• Reverse Proxies add a layer of abstraction and control for incoming requests to web servers.

• API Gateways manage and secure access to a group of microservices, providing a unified interface for clients.

First reference:

https://www.linkedin.com/posts/rocky-bhatia-a4801010_understanding-load-balancers-reverse-proxies-activity-7246126597433384960-3x0X?utm_source=share&utm_medium=member_desktop