Core Compute Services

Question 1

What is an image?

Answer 1

A software bundle that was built from a template definition and made available within a single AWS region.

Question 2

What is a dedicated instance?

Answer 2

A regular EC2 instance that, instead of sharing a physical host with other AWS customers, runs on an isolated host that’s set aside exclusively for our account.

Question 3

What is the most expensive instance?

Answer 3

On-demand (you pay for every hour the instance is running regardless of whether you’re actually using it)

Question 4

When should you run an on-demand instance?

Answer 4

When you need to run for a limited time without interruption (i.e. your ecommerce site is offering a one-day, 50% sale)

Question 5

When should you run a reserved instance?

Answer 5

When your application needs to run uninterrupted for more than a month at a time

Question 6

When should you run a spot instance?

Answer 6

When you don’t need to run constantly and can survive unexpected shutdowns (i.e. development environments or containerized big data workloads)

Question 7

What is the catch with spot instances?

Answer 7

While it’s possible to save up to 90% off of on-demand cost with spot instances, it’s possible that the capacity can, within two minutes notice, be reclaimed and shut down your instance

Question 8

What are two managed deployment services?

Answer 8

Lightsail

Elastic Beanstalk

Question 9

What do you need to configure with Lightsail?

Answer 9

Set the pricing level (billed at a flat rate)

Add an optional script to run at startup

Question 10

What do you need to set up Elastic Beanstalk?

Answer 10

Define application platform

Upload your code!

Question 11

What is a downside to Elastic Beanstalk?

Answer 11

You don’t get to choose how many vCPUs or how much memory you will use. Your application will scale its resource consumption on demand.

Question 12

What AWS resources would you use to orchestrate swarms of Docker containers on AWS using EC2 resources?

Answer 12

ECS (Elastic Container Service)

EKS (Elastic Container Service for Kubernetes)

Question 13

What are Lambda functions?

Answer 13

They are serverless functions that spring into existence, perform a task, and then die down quickly (15min tops). They are only triggered by a preset event.

Question 14

What are instances defined by?

Answer 14

AMIs (or base OS)
Instance type
Storage volumes (either instance volume or EBS)
Pricing model

Question 15

What are the four different AMI categories?

Answer 15

Quick Start

custom (My AMIs)

AWS Marketplace

Community

Question 16

What are the benefits of EBS volumes?

Answer 16

They are versatile (can be converted to AMIs) and they survive an instance shut down.

Question 17

What are the benefits of instance store volumes?

Answer 17

Faster reads/writes (because they are located on the physical server hosting your instance).

Question 18

What is a vCPU?

Answer 18

A virtual central processing unit is a metric that roughly measures an instance type’s compute power in terms of the number of processors on a physical server.

Question 19

What happens when you purchase an EC2 reserved instance?

Answer 19

Charges for any instances you run matching the reserved instance type will be covered by the reservation.

Question 20

What AWS services use primarily EC2 resources under the hood?

Answer 20

Lightsail

Elastic Beanstalk

Question 21

What is the difference between a dedicated instance and a dedicated host?

Answer 21

Dedicated hosts will ensure that the underlying host will NOT change even if the server is stopped. Dedicated instances can change the underlying host.