Notes on: AWS Essentials: 9) ELB

Just a place to put some notes on the “AWS Essentials” course from https://linuxacademy.com

9) Elastic Load Balancer (ELB)

9.1) ELB Basics

ELB = Elastic Load Balancer

ELB...

...evenly distributes incoming application traffic across multiple EC2 instances in multiple Availability Zones (increases fault tolerance.)

...detects unhealthy instances and routes traffic only to healthy instances.

Pricing/Cost Overview

Free Tier use is NOT available for ELB.

Charged:

(1) Each hour or partial hour the load balancer is running

(2) For each GB of data transferred through the load balancer

Note: Prices may vary depending on Region

https://aws.amazon.com/elasticloadbalancing/classicloadbalancer/pricing/

9.2) Creating an ELB

Services > EC2 > Load Balancing: Load Balancers > Create Load Balancer

Two types:

(1) Application Load Balancer

(2) Classic Load Balancer

Image: Services > EC2 > Load Balancing: Load Balancers > Create Load Balancer

High-Level Steps Creating an ELB:

1. Define Load Balancer

2. Assign Security Groups

3. Configure Security Settings

4. Configure Health Check

5. Add EC2 Instances

6. Add Tags

7. Review

9.3) Quiz: ELB Essentials

Q: What best describes the purpose of an ELB?

A: To evenly distribute traffic between EC2 instances.

T: Using an ELB with only one EC2 instance would provide NO additional benefit, and you would be charged money for using it.

T: ELB stands for Elastic Load Balancer.

T: Health checks are required so that the ELB does not serve traffic to an unhealthy EC2 instance.

Q: If you are using an ELB to serve web traffic to EC2 instances, what traffic MUST be allowed on the ELB’s security group, while also maintaining AWS security best practices?

A: HTTP/Port 80