Load balancer vs API Gateway vs Reverse Proxy

After hearing all three of them, you might be a little confused about their working, their properties and why do we need them?

Today we will understand Each term and will use diagrams to understand what they are and what they do.

LOAD BALANCER

Load balancer is used to distribute incoming requests into multiple backend servers. These multiple backend servers are actually the same instances of the server

As you can see in the above image, the load balancer is getting requests from client and distributing the requests into multiple servers.

It checks if the servers are online. If they are offline, it avoids sending requests to that server.

As a single server may not be able to handle millions of requests, we deploy multiple instances of the application and use a load balancer to distribute traffic among them.

One of the most commonly used algorithms is Round Robin. we can change them into other algorithms.

In short, a load balancer distributes incoming traffic across multiple backend servers to improve scalability, availability, and reliability.

API GATEWAY

Now let’s understand API Gateway.

API Gateway is a single entry point for clients to access multiple backend services

API Gateway has connections with all the other different services.

API Gateway sits in front of multiple services and routes client requests to the appropriate service

As we can see in the above image, the API gateway sits before backend services. When a client sends a request to the API Gateway, it makes an API call to another service depending on the user’s request. In the above image, we have four services.

The API Gateway routes incoming requests to the appropriate backend service. It communicates with multiple backend services. In a microservices architecture, the API Gateway acts as a central entry point and routes requests to the appropriate service.

REVERSE PROXY

Now let’s talk about reverse proxy. One of the most popular reverse proxy servers is NGINX. In the last blog post, we understood nginx and how it can concurrently handle more than 10,000 connections.

Reverse proxy sits in front of your Backend Server. It hides the IP address of our web server. It is commonly used for security, SSL termination, caching, performance optimization, and request forwarding.

A reverse proxy reduces direct exposure of backend servers and can add security features such as rate limiting, IP filtering, WAF integration, and SSL termination.

Reverse proxies can help mitigate certain DDoS attacks through rate limiting and traffic filtering, often alongside dedicated DDoS protection services.

Load balancer vs API Gateway vs Reverse Proxy in Table format

NGINX [ Reverse Proxy + Load Balancer]

In the last blog we understood Nginx and how it can do a lot of things.

We can use Nginx to do reverse proxy and load balancing.

We need to define the reverse proxy and load balancing configuration in the nginx.conf file.

How to use them all in our architecture

Let’s understand how we can use them in production.

The above example explains how we can use all three technologies in our architecture.

The Reverse Proxy is exposed to the Internet.

As we all see, a reverse proxy helps us in a lot of various things like caching, SSL termination, and it is also commonly used for security.

The request then goes to the load balancer which distributes the Request into multiple API gateways.

The API Gateway forwards requests to the appropriate backend services.

Similar architectures are commonly used in large-scale microservices applications such as social media platforms.

In a nutshell, choose a Reverse Proxy for stealth, an API Gateway for organized communications, and a Load Balancer for traffic control. Sometimes, it’s wise to have all three — they make a super team that keeps your digital kingdom safe and efficient.