Elastic Load Balancing
Table of Contents
Elastic Load Balancing automatically distributes your incoming traffic across multiple targets (EC2 instances, containers, IP addresses) in one or more Availability Zones.
It monitors the health of its registered targets and routes the traffic only to healthy targets.
AWS Elastic Load Balancing Introduction
Benefits of using Load Balancer #
Spread load across multiple downstream instances
Expose a single point of access (DNS) to the application
Seamlessly handle failures of downstream instances
Do regular health checks to the instances
SSL termination
High Availability across Availability Zones
ELB is a managed Load Balancer
- AWS is responsible for upgrades, maintenance and High Availability
- AWS provides only a few configuration items
3 kinds of Load Balancers offered by AWS #
Application Load Balancer | Network Load Balancer | Gateway Load Balancer |
---|---|---|
HTTP / HTTPS / gRPC protocols (Layer 7) | TCP / UDP protocols (Layer 4) | Geneve Protocol on IP Packets (Layer 3) |
HTTP Routing features | High Performance (millions or requests per second) | Route Traffic to Firewalls that you manage on EC2 instances |
Static DNS (URL) | Static IP through Elastic IP | Intrusion Detection |
1. Application Load Balancer #
- HTTP / HTTPS only (Layer 7)
2. Network Load Balancer #
- ultra high performance, allows for TCP (Layer 4)
3. Gateway Load Balancer #
- Supports GENEVE protocol. Built for extra security (Layer 3)
» Sources « #
- https://aws.amazon.com/elasticloadbalancing/
- https://aws.amazon.com/compare/the-difference-between-the-difference-between-application-network-and-gateway-load-balancing/
- https://medium.com/@xiaotiancheng.orange/comparison-between-alb-nlb-and-glb-4444f3291173
- https://tutorialsdojo.com/application-load-balancer-vs-network-load-balancer-vs-gateway-load-balancer/
Stephane Maarek’s AWS playlists on YouTube: https://www.youtube.com/@StephaneMaarek/playlists Full YouTube Rahul’s AWS Course: https://www.youtube.com/playlist?list=PL7iMyoQPMtAN4xl6oWzafqJebfay7K8KP
» References « #
» Table of contents (CLF-C02) « #
» Disclaimer « #
Disclaimer: Content for educational purposes only, no rights reserved.
Most of the content in this series is coming from Stephane Maarek’s Ultimate AWS Certified Cloud Practitioner CLF-C02 2025 course on Udemy.
I highly encourage you to take the Stephane’s courses as they are awesome and really help understanding the subject.
More about Stephane Maarek:
This article is just a summary and has been published to help me learning and passing the practitioner exam.