What is ELB?

Elastic Load Balancing (ELB) automatically distributes incoming application traffic across multiple targets, such as EC2 instances, containers, and IP addresses.

Key benefits:

• High availability: Traffic automatically rerouted to healthy instances
• Fault tolerance: Eliminates single points of failure
• Scalability: Works with Auto Scaling Groups for dynamic workloads
• Security: Integrates with SSL/TLS and security groups

Example (kaptaindevops):

kaptaindevops runs a web application with multiple EC2 instances. ELB ensures users are always routed to healthy servers, even if one instance fails.

Types of ELB

AWS provides three main types of load balancers:

1. Application Load Balancer (ALB)

• Layer: OSI Layer 7 (Application layer)
• Use Case: HTTP/HTTPS traffic, microservices, container-based applications
• Features:
  • Path-based routing
  • Host-based routing
  • WebSocket support
  • Can integrate with AWS WAF for security

Example (kaptaindevops):

kaptaindevops deploys multiple microservices (service1, service2). ALB routes /api/service1 requests to service1 instances and /api/service2 requests to service2 instances.