Question 449 - CLF-C02 discussion

Reserved Instances (RIs) are a pricing model that allows you to reserve EC2 instances for a specified period of time (one or three years) and receive a significant discount compared to On-Demand pricing. RIs are suitable for workloads that have predictable usage patterns and require a long-term commitment. You can choose between three payment options: All Upfront, Partial Upfront, or No Upfront.The more you pay upfront, the greater the discount1.

Savings Plans are a flexible pricing model that can help you reduce your EC2 costs by up to 72% compared to On-Demand pricing, in exchange for a commitment to a consistent amount of usage (measured in $/hour) for a one or three year term. Savings Plans apply to usage across EC2, AWS Lambda, and AWS Fargate. You can choose between two types of Savings Plans: Compute Savings Plans and EC2 Instance Savings Plans. Compute Savings Plans offer the most flexibility and apply to any instance family, size, OS, tenancy, or region.EC2 Instance Savings Plans offer the highest discount and apply to a specific instance family within a region2.

Spot Instances are a pricing model that allows you to bid for unused EC2 capacity in the AWS cloud and are available at a discount of up to 90% compared to On-Demand pricing. Spot Instances are suitable for fault-tolerant or stateless workloads that can run on heterogeneous hardware and have flexible start and end times.However, Spot Instances are not guaranteed and can be interrupted by AWS at any time if the demand for capacity increases or your bid price is lower than the current Spot price3.

On-Demand Instances are a pricing model that allows you to pay for compute capacity by the hour or second with no long-term commitments. On-Demand Instances are suitable for short-term, spiky, or unpredictable workloads that cannot be interrupted, or for applications that are being developed or tested on EC2 for the first time.However, On-Demand Instances are the most expensive option among the four pricing models4.

Dedicated Hosts are physical EC2 servers fully dedicated for your use. Dedicated Hosts can help you reduce costs by allowing you to use your existing server-bound software licenses, such as Windows Server, SQL Server, and SUSE Linux Enterprise Server. Dedicated Hosts can be purchased On-Demand or as part of Savings Plans. Dedicated Hosts are suitable for workloads that need to run on dedicated physical servers or have strict licensing requirements. However, Dedicated Hosts are not the lowest cost option among the four pricing models.