Elastic Load Balancing (ELB)
- Load balancers are servers that forward internet traffic to multiple servers (EC2 Instances) downstream.
- Spread Load across multiple downstream instances
- Expose single point of access (DNS) to your application
- Do regular health checks to your instances
- Provide SSL termination (https) for your websites
- High availability across zones
- its managed so AWS guarantees it will be working, take care of upgrades, maintenance, and high availability
- This incurs higher cost than setting up your own load balancer, but the trade off is less personal effort towards setup, maintenance and integrations
Types of LBs offered by AWS (3)
Application load balancer
- HTTP/HTTPS only, which means it works at layer 7
Network load balancer
- Ultra-high performance
- Keyword to look for on the exam
- Gaming situations
- Millions of requests per second
- Allows for tcp, which means it works at Layer 4
Classic load balancer
- The exam will never ask you to choose this as it is being slowly retired
- Works at layers 4 and 7
Overview
Key words