EC2

Question 1

For what type of use are on-demand EC2 instances recommended?

Answer 1

Short-term

Question 2

What is the difference between a standard reserved instance and a convertible reserved instance?

Answer 2

With a standard reserved instance you must specify the instance type, region, tenancy and OS.
For a convertible RI you can change these.

Question 3

What is the difference between reserved instances and savings plans?

Answer 3

For a savings plan, the user is committing to a certain level of usage (in ££) per hour for the next 1 - 3 years. They are also locked into a specific instance family.

For a RI, you do not specify the usage ph, you are solely stating the length in years for which you would like to reserve the instances.

Question 4

What is a dedicated host type of EC2 instance? When would you use it?

Answer 4

A physical server that is fully dedicated to your use case.
Good if you have strong regulatory or compliance needs.

Question 5

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

Answer 5

A dedicated host is a whole physical server which is dedicated to the user, from which you can spring up dedicated instances. The user can use software licenses bound to a server on these.

A dedicated instance is an instance that runs on hardware that only that user can access, but they don’t have control over the physical characteristics of the hardware itself such as host IDs or ports

Question 6

What are capacity reservations?

Answer 6

When a user reserves on-demand instances’ capacity in a specific AZ. They are charged an on-demand rate whether they actually use the instances or not.

Question 7

What is the most cost-efficient type of EC2 purchase plan?

Answer 7

Spot instances