AWS Elastic Load Balancer: Guide to High Availability and Scalability

In today’s cloud-driven world, where businesses demand resilience, speed, and adaptability, building robust applications is no longer optional, it’s essential. Imagine a bustling airport terminal with passengers arriving from all directions. To keep things running smoothly, traffic needs to be directed, whether to check-in counters, security lines, or gates. AWS Elastic Load Balancer is a powerful service that provides load balancing incoming traffic between multiple targets, which could be instances of EC2, containers, IP addresses, and Lambda. Herein, in this article, I'll give an overview of ELB and its important options to make your choice of load balancer right for your use case.

AWS Elastic Load Balancer automatically distributes incoming application or network traffic across multiple targets in one or more availability zones (AZs). By acting as a traffic distribution layer, ELB enhances fault tolerance, scalability, and availability, ensuring your applications can handle varying levels of demand seamlessly.

So, what are the use cases?? 🧐

It really depends on what type of load balancer you're using. Let's take one-by-one types, and I will give a brief explanation with specific use cases.

1. Application Load Balancer (ALB)

Think of the Application Load Balancer as the ultimate traffic controller for web apps. It specializes in handling HTTP and HTTPS traffic, operating at the application layer to guide incoming requests based on specific details such as finely tuned GPS for your traffic. This makes ALB the go-to choice for modern architectures such as microservices, web applications, and RESTful APIs.

Imagine this: You’re running an e-commerce platform. With ALB, you can easily direct customers to the right microservices. For example, requests to /cart are routed to the shopping cart service, while /checkout requests go straight to the payment system.

Smooth, right?

2. Network Load Balancer (NLB)

Let's talk about the powerhouse of traffic management. Network Load Balancer is purpose-built to handle huge volumes of traffic with incredible speed. Operating at the transport layer, it’s designed for TCP and UDP traffic, and it absolutely shines under pressure, managing low-latency, high-throughput workloads like a pro. In fact, the NLB is so efficient it can scale to handle millions of requests per second without breaking a sweat.

Imagine this: You’re running a real-time gaming platform or managing a financial app where even the tiniest delay is unacceptable. The NLB steps in to ensure every request is processed quickly and reliably, even when traffic surges, such as a tidal wave. It’s the definition of “always-on” performance.

3. Gateway Load Balancer (GLB)

Think of the Gateway Load Balancer as the Swiss Army knife for your traffic. It combines the capabilities of a load balancer and a gateway into one neat solution, making it ideal for scenarios where your traffic needs to pass through virtual appliances like firewalls, intrusion detection systems, or network monitoring tools. It’s all about streamlining complex tasks and doing the heavy lifting for you.

Here’s a scenario: Let’s imagine you’re developing a high-security application where every bit of traffic needs to pass through a virtual firewall for inspection. GLB takes care of routing all that traffic seamlessly, which means no manual intervention is required. It’s built to handle these tasks effortlessly, letting you focus on the bigger picture while ensuring your app stays secure.

So, that’s it about AWS Elastic Load Balancer.

I hope you got something new!

Have a great day!

GIF