Which EC2 instance purchasing option will meet these requirements MOST cost-effectively?
Standard Reserved Instance
Convertible Reserved Instance
On-Demand Instance
Spot Instance
Explanations:
Standard Reserved Instances offer a significant discount for a one-year commitment and are ideal for predictable workloads that run constantly, such as a database server.
Convertible Reserved Instances allow flexibility to change instance types, but they are generally more expensive than Standard Reserved Instances for a specific one-year commitment.
On-Demand Instances are more expensive for continuous use over a long period, as they are billed hourly without any long-term discounts.
Spot Instances are the least expensive option, but they can be interrupted by AWS, making them unsuitable for a database server that needs to run constantly.