All 7 Elastic Load Balancing (ALB, NLB & CLB) questions
More in Elastic Load Balancing (ALB, NLB & CLB)
What is the difference between an Application Load Balancer, a Network Load Balancer, and a Classic Load Balancer? How do target groups and health checks work together within an Application Load Balancer to route traffic only to healthy instances? How does path based and host based routing on an Application Load Balancer support directing traffic to different backend services within a single load balancer? How does a Network Load Balancer's preservation of the client's source IP address benefit certain applications compared to an Application Load Balancer? How can Application Load Balancer support sticky sessions, and when is this feature actually necessary for an application? How do you design a load balancer architecture that supports zero downtime blue green or canary deployments for a production application?
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AWS › Elastic Load Balancing (ALB, NLB & CLB)

What is Elastic Load Balancing and why is it important for building scalable, highly available applications?

Beginner

Answer

Elastic Load Balancing automatically distributes incoming application traffic across multiple targets, such as EC2 instances or containers, in one or more Availability Zones, improving both the fault tolerance of your application, since traffic automatically avoids unhealthy targets, and its ability to scale, since you can add or remove capacity behind the load balancer without any interruption to end users.
aws elbv2 create-load-balancer --name my-load-balancer --subnets subnet-12345 subnet-67890
Real-world example An online retailer places a load balancer in front of its fleet of EC2 instances, ensuring that if one instance becomes unhealthy during a traffic surge, the load balancer automatically stops sending it traffic while continuing to serve customers through the remaining healthy instances.

Common follow-ups: What is the difference between the three types of load balancers AWS offers?;How does a load balancer determine whether a target is healthy?

Auto Scaling Groups;EC2 & Compute
All 7 Elastic Load Balancing (ALB, NLB & CLB) questions