What is an Elastic Load Balancer?
This post covers basics of what an Elastic Load Balancer is, and two of its examples: Application Load Balancers and Classic Load Balancers. For additional information — including a comparison that explains Network Load Balancers — check out our post on “What is a Network Load Balancer and When Should I Use It.”
Elastic Load Balancer basics
An Elastic Load Balancer (ELB) is one of the key architecture components for many applications inside the AWS cloud. In addition to autoscaling, it enables and simplifies one of the most important tasks of our application’s architecture: scaling up and down with high availability.
Elastic Load Balancing automatically distributes incoming application traffic across multiple applications, microservices, and containers hosted on Amazon EC2 instances.
One of the many advantages of using ELB is the fact that it is elastic (i.e. changeable), which means that it will automatically scale to meet your incoming traffic. If you are a system administrator or a DevOps engineer running a load balancer by yourself, you’ve got to also carry the burden of scaling a load balancer and enabling high availability. With ELB, you can create your load balancer and enable dynamic scaling with just a few clicks.
Check out this short video, taken from the Using Elastic Load Balancing & EC2 Auto Scaling to support AWS workloads Course, which explains what an AWS ELB is and what it can be used for.
Since it was first released in 2009, ELB has gained numerous improvements and features. The Application Load Balancer (ALB) is a logical step forward in developing load balancing possibilities inside the AWS cloud. With this addition, the original load balancer has been renamed Classic Load Balancer, and is still available for use inside the AWS cloud.
Let’s dig into some features of Application Load Balancer compared to the original, show you