Your company is planning to make use of the Elastic Container service for managing their container-based applications. They are going to process both critical and non-critical workloads with these applications. Which of the following COST effective setup would they consider?

Answer options:

A.Use ECS orchestration and Spot Instances for processing critical data and On-Demand for the non-critical data.
B.Use ECS orchestration and On-Demand Instances for processing critical data and Spot Instances for the non-critical data.
C.Use ECS orchestration and Spot Instances for both the processing of critical data and non-critical data.
D.Use ECS orchestration and On-Demand Instances for both the processing of critical data and non-critical data.

Answer – B
Spot Instance and On-demand Instance are very similar in nature. The main difference between these is a commitment. In Spot Instance, there is no commitment. As soon as the Bid price exceeds the Spot price, a user gets the Instance. In an On-demand Instance, a user has to pay the On-demand rate specified by Amazon. Once they have bought the Instance, they have to use it by paying that rate.
In Spot Instance, once the Spot price exceeds the Bid price, Amazon will shut the instance. The benefit to the user is that they will not be charged for the partial hour in which the Instance was taken back from them.
Spot instances are not always cheaper than on-demand, they can and do sometimes fluctuate wildly, even to very high per hour amounts, higher than the on-demand price at times.
A Spot Instance is an unused EC2 instance that is available for less than the On-Demand price. Because Spot Instances enable you to request unused EC2 instances at steep discounts, you can significantly lower your Amazon EC2 costs. The hourly price for a Spot Instance is called a Spot price. The Spot price of each instance type in each Availability Zone is set by Amazon EC2 and adjusted gradually based on the long-term supply of and demand for Spot Instances. Your Spot Instance runs whenever capacity is available, and the maximum price per hour for your request exceeds the Spot price.
Options A and C are incorrect since Spot Instances can be taken back or interrupted and should not be used for critical workloads.
Option D is not a cost-effective solution. You can use Spot Instances for non-critical workloads.
For more information on Spot Instances, please refer to the below URL-
https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-spot-instances.html