Availability & Scalability of EC2

Vertical scaling → increase instance size

Horizontal → more instances

High Availability → run instances for same application across multiple AZ

Load Balancers

Load balancers are servers that forward traffic to multiple servers downstream.

• Load balancers let you spread load across multiple downstream instances.
• It exposes a single point of access to your application.
• Handles failures of downstream instances
• Provide SSL termination for your websites
• Enforce stickiness with cookies
• High availability across zones
• Separate public traffic from private traffic

Why use an ELB?

• Its a managed load balancer
• Costs less to setup your own load balancer, but will be a lot more effort on your end
• Integrated with AWS