EC2 Purchase Options Flashcards
What are the main EC2 Purchase Options?
The main EC2 Purchase Options are On-Demand Instances, Reserved Instances, Savings Plans, Spot Instances, and Dedicated Hosts.
What are On-Demand Instances?
On-Demand Instances let you pay for compute capacity by the hour or second (minimum of 60 seconds) with no long-term commitments. This gives you the flexibility to run instances for as long or short as you need.
What are Reserved Instances?
Reserved Instances provide you with a significant discount (up to 75%) compared to On-Demand Instance pricing. In exchange, you commit to a one or three-year term of use. They are best suited for applications with steady state usage.
What are Savings Plans?
Savings Plans are a flexible pricing model that offer lower rates compared to On-Demand pricing, similar to Reserved Instances, but with more flexibility in how you use compute capacity. They commit you to a specific amount of usage (in $/hour) for a one or three-year term.
What are Spot Instances?
Spot Instances allow you to request unused EC2 capacity at significant discounts, making them ideal for fault-tolerant and flexible applications. Spot Instance prices are determined by supply and demand for EC2 excess capacity.
What are Dedicated Hosts?
Dedicated Hosts are physical servers with EC2 instance capacity fully dedicated to your use. They can help you meet compliance requirements and reduce costs by allowing you to use your existing server-bound software licenses.
How do Spot Instances differ from On-Demand Instances?
Spot Instances offer the same capacity as On-Demand Instances but at lower prices, with the trade-off being that they can be interrupted by AWS with two minutes of notification. On-Demand Instances, however, provide steady and uninterrupted service.
What factors should be considered when choosing an EC2 Purchase Option?
Factors include: cost, application requirements, flexibility needed, potential for interruption, compliance and licensing considerations, and usage predictability.
Can EC2 Reserved Instances be modified?
Yes, EC2 Reserved Instances can be modified in terms of instance type, instance family, operating system, tenancy, and Availability Zones, offering some flexibility after purchase.
How can you use Dedicated Hosts to save on costs?
You can save costs with Dedicated Hosts by utilizing your existing server-bound software licenses (such as Windows Server or SQL Server) that cannot be used with standard multi-tenant hosting, potentially reducing overall costs.
What strategy can be used to maximize savings with EC2 Purchase Options?
A combination strategy using Reserved Instances or Savings Plans for baseline capacity and complementing with On-Demand or Spot Instances for peak loads can optimize costs while ensuring capacity needs are met.
