AWS Certified Solutions Architect – Professional — Question 699

A data analytics company has an Amazon Redshift cluster that consists of several reserved nodes. The cluster is experiencing unexpected bursts of usage because a team of employees is compiling a deep audit analysis report. The queries to generate the report are complex read queries and are CPU intensive.
Business requirements dictate that the cluster must be able to service read and write queries at all times. A solutions architect must devise a solution that accommodates the bursts of usage.
Which solution meets these requirements MOST cost-effectively?

Answer options

• A. Provision an Amazon EMR cluster. Offload the complex data processing tasks.
• B. Deploy an AWS Lambda function to add capacity to the Amazon Redshift cluster by using a classic resize operation when the cluster's CPU metrics in Amazon CloudWatch reach 80%.
• C. Deploy an AWS Lambda function to add capacity to the Amazon Redshift cluster by using an elastic resize operation when the cluster's CPU metrics in Amazon CloudWatch reach 80%
• D. Turn on the Concurrency Scaling feature for the Amazon Redshift cluster.

Correct answer: D

Explanation

Enabling Concurrency Scaling is the most cost-effective and seamless solution because Amazon Redshift automatically adds transient cluster capacity to handle bursts of read queries, and customers accumulate free Concurrency Scaling credits daily. Classic and elastic resize operations are not ideal because they can introduce write downtime or take too long to provision for sudden, temporary bursts. Migrating workloads to Amazon EMR introduces unnecessary architectural complexity and higher baseline costs compared to utilizing Redshift's native scaling capabilities.