Elastic Load Balancing and EC2 Scaling

Question 1

What is ELB?

Answer 1

ELB automatically distributes incoming application traffic across multiple targets, such as Amazon EC2 instances, containers, and IP addresses.

Question 2

What are the three types of ELBs?

Answer 2

• Application Load Balancer (ALB) – layer 7 load balancer that routes connections based on the content of the request (HTTP requests).
• Network Load Balancer (NLB) – layer 4 load balancer that routes connections based on IP protocol data (TCP traffic).
• Classic Load Balancer (CLB) – this is the oldest of the three and provides basic load balancing at both layer 4 and layer 7.

Question 3

What is Auto Scaling?

Answer 3

AWS Auto Scaling automates the process of adding (scaling up) OR removing (scaling down) EC2 instances based on the traffic demand for your application.

Auto Scaling helps to ensure that you have the correct number of EC2 instances available to handle the application load.

Question 4

What is an Auto Scaling Group?

Answer 4

Collections of EC2 instances

A desired capacity can be configured and AWS Auto Scaling will ensure the group has this number of instances.