Overview
Elastic Load Balancing (ELB) is a cloud service that automatically distributes incoming application traffic across multiple targets, such as Amazon EC2 instances, containers, IP addresses, and Lambda functions. It can handle the varying load of your application traffic in a single Availability Zone or across multiple Availability Zones.
Key Concepts
- High Availability: ELB ensures that traffic is only routed to healthy targets.
- Scalability: It scales automatically to handle increases in traffic without manual intervention.
- Health Checks: Periodically monitors the health of registered targets to ensure they can handle requests.
Types of ELB
- Application Load Balancer (ALB): Best for HTTP and HTTPS traffic.
- Network Load Balancer (NLB): Best for TCP, UDP, and TLS traffic where extreme performance is required.
- Gateway Load Balancer (GWLB): Used for deploying and managing third-party virtual appliances.