AWS Certified Solutions Architect – Professional — Question 1017

A company ingests and processes streaming market data. The data rate is constant. A nightly process that calculates aggregate statistics is run, and each execution takes about 4 hours to complete. The statistical analysis is not mission critical to the business, and previous data points are picked up on the next execution if a particular run fails.
The current architecture uses a pool of Amazon EC2 Reserved Instances with 1-year reservations running full time to ingest and store the streaming data in attached Amazon EBS volumes. On-Demand EC2 instances are launched each night to perform the nightly processing, accessing the stored data from NFS shares on the ingestion servers, and terminating the nightly processing servers when complete. The Reserved Instance reservations are expiring, and the company needs to determine whether to purchase new reservations or implement a new design.
Which is the most cost-effective design?

Answer options

• A. Update the ingestion process to use Amazon Kinesis Data Firehose to save data to Amazon S3. Use a fleet of On-Demand EC2 instances that launches each night to perform the batch processing of the S3 data and terminates when the processing completes.
• B. Update the ingestion process to use Amazon Kinesis Data Firehouse to save data to Amazon S3. Use AWS Batch to perform nightly processing with a Spot market bid of 50% of the On-Demand price.
• C. Update the ingestion process to use a fleet of EC2 Reserved Instances behind a Network Load Balancer with 3-year leases. Use Batch with Spot instances with a maximum bid of 50% of the On-Demand price for the nightly processing.
• D. Update the ingestion process to use Amazon Kinesis Data Firehose to save data to Amazon Redshift. Use an AWS Lambda function scheduled to run nightly with Amazon CloudWatch Events to query Amazon Redshift to generate the daily statistics.

Correct answer: B

Explanation

Option B is the most cost-effective because it combines Amazon Kinesis Data Firehose with AWS Batch using Spot instances, significantly reducing costs compared to On-Demand instances. Option A may incur higher costs due to using On-Demand instances for processing, while Option C locks the company into long-term Reserved Instances which may not be necessary. Option D introduces complexity and potential costs associated with using Amazon Redshift and Lambda functions.