Understanding Application Load Balancers and Their Core Components

Introduction

In the ever-evolving world of cloud computing, one of the key challenges that organizations face is ensuring their applications are highly available, scalable, and secure. Amazon Web Services (AWS) offers a plethora of services to address these concerns, and one of the cornerstone services in this regard is the AWS Application Load Balancer (ALB).

Application Load Balancer components

Load balancer

A load balancer plays a crucial role by acting as the central gateway for client requests. It performs the essential task of distributing incoming traffic from clients across a group of target resources, which could include EC2 instances located in different Availability Zones. This distribution of traffic enhances the overall availability and resilience of your application. To configure a load balancer effectively, you’ll typically set up one or more listeners, which determine how incoming traffic is handled and routed.

Listener

A listener serves as a critical component responsible for monitoring incoming connection requests from clients, and it operates based on the specific protocol and port configuration you have set. Within a listener, you establish rules that dictate how the load balancer should direct these requests to its designated targets. These rules are composed of several key elements: a priority level, one…