EC2

Question 1

On-Demand Instance

Answer 1

short workload, predictable pricing, pay by second

• Linux or Windows - billing per second, after the first minute
• All other operating systems - billing per hour
• Has the highest cost but no upfront payment
• No long-term commitment
• Recommended for short-term and un-interrupted workloads, where you can’t predict how the application will behave

Question 2

Spot Instance

Answer 2

• Can get a discount of up to 90% compared to On-demand
• Instances that you can “lose” at any point of time if your max price is less than the current spot price
• The MOST cost-efficient instances in AWS
• Useful for workloads that are resilient to failure * Batch jobs
• Data analysis
• Image processing
• Any distributed workloads
• Workloads with a flexible start and end time
• Not suitable for critical jobs or databases

Question 3

Standard Reserved Instance

Answer 3

Reserved (1 & 3 years)

Up to 72% discount compared to On-demand
* You reserve a specific instance attributes (Instance Type, Region,Tenancy, OS)
* Reservation Period – 1 year (+discount) or 3 years (+++discount)
* Payment Options – No Upfront (+), Par tial Upfront (++), All Upfront (+++)
* Reserved Instance’s Scope – Regional or Zonal (reserve capacity in an AZ)
* Recommended for steady-state usage applications (think database)
* You can buy and sell in the Reserved Instance Marketplace

Question 4

Convertible Reserved Instance

Answer 4

Reserved (1 & 3 years)

• Reserved Instances – long workloads
• Convertible Reserved Instance
• Can change the EC2 instance type, instance family, OS, scope and tenancy * Up to 66% discount

Question 5

Dedicated Host

Answer 5

book an entire physical server, control instance placement

• A physical server with EC2 instance capacity fully dedicated to your use
• Allows you address compliance requirements and use your existing server- bound software licenses (per-socket, per-core, pe—VM software licenses)
• Purchasing Options:
• On-demand – pay per second for active Dedicated Host
• Reserved - 1 or 3 years (No Upfront, Partial Upfront,All Upfront)
• The most expensive option
• Useful for software that have complicated licensing model (BYOL – Bring Your
  Own License)
• Or for companies that have strong regulatory or compliance needs

Question 6

Dedicated Instance

Answer 6

no other customers will share your hardware

• Instances run on hardware that’s dedicated to you
• May share hardware with other instances in same account
• No control over instance placement (can move hardware after Stop / Start)

Question 7

Capacity Reservations

Answer 7

reserve capacity in a specific AZ for any duration

• Reserve On-Demand instances capacity in a specific AZ for any
  duration
• You always have access to EC2 capacity when you need it
• No time commitment (create/cancel anytime), no billing discounts
• Combine with Regional Reserved Instances and Savings Plans to benefit from billing discounts
• You’re charged at On-Demand rate whether you run instances or not
• Suitable for short-term, uninterrupted workloads that needs to be in a
  specific AZ

Question 8

Savings Plan

Answer 8

(1 & 3 years) –commitment to an amount of usage, long workload

• Get a discount based on long-term usage (up to 72% - same as RIs) * Commit to a certain type of usage ($10/hour for 1 or 3 years)
• Usage beyond EC2 Savings Plans is billed at the On-Demand price
• Locked to a specific instance family & AWS region (e.g., M5 in us-east-1)
• Flexible across:
• Instance Size (e.g., m5.xlarge, m5.2xlarge) * OS (e.g., Linux, Windows)
• Tenancy (Host, Dedicated, Default)