Which EC2 option is best for long-term workloads with predictable usage patterns?

Reserved instances are designed specifically for long-term workloads with predictable usage patterns. By committing to a one- or three-year term, you benefit from significant cost savings compared to On-Demand pricing, which is ideal for customers who can forecast their resource needs. This commitment allows you to pay a lower rate based on the expected usage, making it a cost-effective solution for stable workloads that consistently require a certain level of computing capacity.

In contrast, On-Demand Instances offer flexibility for variable usage, making them better suited for spiky or unpredictable workloads. Spot Instances are typically used for applications that can tolerate interruptions, and are generally only available when there is excess capacity in the AWS cloud, making them unsuitable for steady workloads. Dedicated Hosts provide physical servers for instances but do not inherently address cost savings or long-term usage in the same way that Reserved Instances do. Therefore, Reserved Instances are the best choice for scenarios where long-term, predictable workloads are involved.