SAA-C03 Design Cost-Optimized Architectures Practice Test 17 — 15 Questions

Question 1

A company stores millions of small, rarely accessed backup objects in Amazon S3 Standard. The objects must remain immediately retrievable within milliseconds and be retained for at least five years, but the company wants to reduce storage cost. Which action should the company take?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

Add a lifecycle rule to transition the objects to S3 Standard-IA after 30 days.. S3 Standard-IA keeps objects immediately accessible with millisecond latency while charging less per gigabyte than S3 Standard, which matches the requirement to retain rarely accessed backups for five years without retrieval delays. A lifecycle rule can transition the objects automatically after 30 days. Glacier Deep Archive is cheaper but too slow, Intelligent-Tiering adds monitoring fees on small objects, and One Zone-IA sacrifices AZ resilience.

Answer

Convert the bucket to S3 One Zone-IA to save on storage and retrieval.

Answer

Add a lifecycle rule to transition the objects to S3 Glacier Deep Archive after 30 days.

Answer

Enable S3 Intelligent-Tiering and rely on it to move objects automatically.

Question 2

A solutions architect is reviewing an Amazon S3 bucket that stores application assets. The bucket has S3 Versioning enabled and accumulates many noncurrent object versions that are no longer needed. The team wants to reduce storage cost while preserving the ability to recover from accidental deletions of current objects. Which two actions should the architect take? (Choose two.)

Accepted Answer

Configure a lifecycle rule to expire noncurrent versions after a defined number of days.. The two cost drivers are accumulated noncurrent versions and lingering incomplete multipart uploads. A lifecycle rule expiring noncurrent versions removes unneeded old copies while preserving current-object recovery, and a rule aborting incomplete multipart uploads eliminates billable orphaned parts. Together they reduce storage cost without disabling versioning or harming retrieval of active assets.

Answer

Enable S3 Transfer Acceleration on the bucket to reduce storage charges.

Answer

Transition current object versions to S3 Glacier Deep Archive immediately upon creation.

Answer

Disable S3 Versioning on the bucket to stop new versions from being created.

Question 3

A solutions architect is reviewing a workload that runs on a fleet of Amazon EC2 instances in a single AWS Region. The application serves a global user base, and the team wants to reduce both data transfer costs and latency for users in Europe and Asia. The application is stateless and stores assets in Amazon S3. The team is also evaluating how to pay for the compute layer over the next three years, as usage is expected to be steady. Which two actions will reduce cost in this scenario? (Choose two.)

Accepted Answer

Purchase a three-year Compute Savings Plan with a full upfront payment for the EC2 compute.. The workload has two distinct cost drivers: global asset delivery and steady compute. Caching assets at CloudFront edge locations reduces origin egress and internet transfer while improving latency for distant users. For the compute layer, a three-year Compute Savings Plan matches the expected steady usage and applies a significant discount over On-Demand. Together these address both transfer and compute costs without sacrificing availability.

Answer

Enable S3 Transfer Acceleration on the bucket and direct all user downloads through the accelerated endpoint.

Answer

Move the S3 bucket to a Region closer to the European users and replicate back to the original Region.

Answer

Convert the EC2 instances to Spot Instances to eliminate compute charges entirely.

Question 4

A financial services firm runs a containerized risk-analysis platform on Amazon EKS. The containers are stateless and the platform runs continuously, but the firm wants a pricing model that reduces compute cost for the steady baseline while still allowing occasional short bursts above the baseline. Which combination of actions best achieves this?

Accepted Answer

Purchase a Compute Savings Plan sized to the steady baseline and run any burst capacity as On-Demand.. Matching a Compute Savings Plan to the steady baseline discounts the always-on portion of the container platform while letting short bursts run at On-Demand rates keeps costs aligned with actual usage. This avoids paying for peak capacity continuously, which is what reserving to peak would do. Spot capacity is cheaper but too unreliable for a production platform that must remain available.

Answer

Purchase a Convertible Reserved Instance for peak capacity and let it automatically cover bursts.

Answer

Purchase a Standard Reserved Instance sized to peak capacity for the entire platform.

Answer

Run the entire platform on Spot Instances to maximize the discount.

Question 5

A company stores several petabytes of archived regulatory records in Amazon S3. The records must be retained for seven years and are almost never accessed, but if an auditor requests a record, it must be retrievable within 12 hours. The company wants the lowest storage cost that still meets the retrieval requirement. Which S3 storage class should the solutions architect choose?

Accepted Answer

S3 Glacier Deep Archive. The lowest-cost storage class that still returns data within the allowed 12-hour window is S3 Glacier Deep Archive, whose standard retrieval completes within 12 hours. Glacier Flexible Retrieval and the Infrequent Access classes cost more per gigabyte, and paying for faster retrieval or millisecond access provides no benefit when the retrieval requirement is so permissive.

Answer

S3 Standard-Infrequent Access

Answer

S3 Glacier Flexible Retrieval

Answer

S3 One Zone-Infrequent Access

Question 6

A team runs a containerized API on Amazon ECS on Fargate in a single Region. Traffic is steady during business hours but drops to near zero overnight, and the team wants to reduce cost without rewriting the application. The team already uses Application Load Balancer and CloudWatch. Which two actions will reduce cost while keeping the API available? (Choose two.)

Accepted Answer

Use Fargate Spot capacity for a portion of the ECS tasks and keep a baseline of on-demand Fargate tasks behind the load balancer.. Combining Fargate Spot for part of the fleet with a small on-demand baseline lowers the hourly compute rate while preserving availability, and target tracking on ALB request count per target shrinks the task count overnight so the service pays only for needed capacity. Together they reduce cost without rewriting the application and keep the API reachable through the load balancer.

Answer

Reduce the Fargate task CPU and memory to the minimum supported values for all tasks regardless of load.

Answer

Switch the ECS service launch type to EC2 and purchase 3-year All Upfront Reserved Instances for the cluster.

Answer

Enable ECS Exec on all tasks and remove the Application Load Balancer to save on ALB hourly charges.

Question 7

A small e-commerce company hosts its product catalog on a single Amazon EC2 instance in a public subnet. Traffic is steady and predictable, and the instance runs 24/7. The company wants to reduce its monthly compute bill without changing the architecture or risking availability. Which action should a solutions architect recommend?

Accepted Answer

Purchase a one-year Standard Reserved Instance for the instance.. For a steady, always-on instance that will not change family or Region, a Standard Reserved Instance delivers a substantial discount over On-Demand with no architectural change and no availability risk. It is the simplest, lowest-risk way to cut the monthly compute bill for this predictable workload.

Answer

Move the instance to a Spot Instance to take advantage of lower hourly rates.

Answer

Enable detailed monitoring and create a CloudWatch alarm to stop the instance when traffic is low.

Answer

Migrate the workload to a smaller instance type and enable burstable performance.

Question 8

A solutions architect is optimizing the cost of a serverless data-processing pipeline. The pipeline uses AWS Lambda functions that process messages from an Amazon SQS queue and write results to Amazon DynamoDB. The team observes that Lambda invocations spike unpredictably, DynamoDB is provisioned with high capacity that is often idle, and the SQS queue occasionally accumulates a large backlog. Which two changes will most directly reduce cost while preserving the pipeline's ability to handle bursts? (Choose two.)

Accepted Answer

Switch the DynamoDB table from provisioned capacity to on-demand capacity mode.. The two most direct cost levers are matching DynamoDB billing to actual traffic by using on-demand capacity, and reducing Lambda invocation count by batching SQS messages with long polling. Together they eliminate idle provisioned capacity and cut per-invocation charges, while both changes preserve the ability to absorb unpredictable bursts without throttling the pipeline.

Answer

Increase the Lambda function's memory allocation to shorten execution time.

Answer

Configure the Lambda function's reserved concurrency to a low fixed value to cap scaling.

Answer

Move the SQS queue to a FIFO queue to improve ordering and throughput.

Question 9

A company runs a containerized order-processing service on Amazon ECS with the Fargate launch type. The service scales out during business hours and scales down to a small baseline overnight. Usage is expected to remain stable for the next two years, and the team wants to reduce Fargate cost without managing any servers. Which action should the solutions architect take?

Accepted Answer

Purchase a Compute Savings Plan that covers the steady Fargate baseline usage. Compute Savings Plans explicitly cover Fargate vCPU and memory usage, so they reduce cost for a serverless container workload without requiring any infrastructure management. Sizing the commitment to the guaranteed overnight baseline discounts the portion of usage that will certainly occur, while the elastic daytime capacity continues to bill at On-Demand rates without over-committing the company.

Answer

Enable Fargate Spot for the entire service and remove the On-Demand baseline

Answer

Purchase a 1-year EC2 Instance Savings Plan sized to the nightly baseline

Answer

Migrate the service to the EC2 launch type and purchase Reserved Instances for the baseline

Question 10

A company runs a stateless web application on a fleet of EC2 instances behind an Application Load Balancer. The instances are in an Auto Scaling group that scales between 4 and 40 instances, and utilization is highly variable. The company wants to reduce compute cost while keeping the ability to change instance families and Regions over the next three years. Which purchasing strategy should the company use?

Accepted Answer

Purchase a Compute Savings Plan with a commitment equal to the steady-state baseline usage.. A Compute Savings Plan discounts eligible compute regardless of family, size, tenancy, or Region, which matches the requirement to change instance families and Regions over three years. Committing only to the steady-state baseline keeps the discount on always-on capacity while variable burst capacity is billed at On-Demand rates, so the company controls cost without sacrificing flexibility.

Answer

Purchase a 3-year Standard Reserved Instance for each of the 40 instances.

Answer

Use Spot Instances for the entire Auto Scaling group and remove the On-Demand capacity.

Answer

Purchase a 1-year EC2 Instance Savings Plan scoped to the current instance family and Region.

Question 11

A healthcare company stores 80 TB of medical imaging data in Amazon S3. The data is written once and must be retained for seven years for compliance. New images are accessed frequently for the first 30 days, then almost never after that, but auditors occasionally request a specific image with no advance notice and expect it within minutes. The company wants to minimize storage cost while meeting the retrieval requirement. Which two actions should a solutions architect recommend? (Choose two.)

Accepted Answer

Configure an S3 Lifecycle policy to transition objects to S3 Glacier Instant Retrieval after 30 days.. Transitioning to S3 Glacier Instant Retrieval after 30 days matches the long-term, rarely accessed pattern while preserving millisecond retrieval for auditor requests, which keeps storage cost low. Adding a seven-year compliance-mode Object Lock enforces the regulatory retention mandate. Together these actions satisfy both the cost and compliance requirements without compromising retrieval speed.

Answer

Enable S3 Versioning on the bucket to protect the imaging data from accidental deletion.

Answer

Configure an S3 Lifecycle policy to transition objects to S3 Glacier Deep Archive after 30 days.

Answer

Configure an S3 Lifecycle policy to transition objects to S3 Standard-IA after 30 days.

Question 12

A small analytics team runs a nightly batch job on a single Amazon EC2 instance. The job starts at 2:00 AM and finishes by 4:00 AM. The instance is idle for the rest of the day. The team wants to reduce EC2 costs and is willing to accept that the instance may be stopped and started. Which action will reduce costs MOST effectively?

Accepted Answer

Stop the instance when the job completes and start it again before the next run using an automated schedule.. When an instance is needed only for a short, predictable window, stopping it during idle hours removes the compute charges for those hours. Automated start and stop scheduling is a simple and effective cost optimization for intermittent workloads. Reserved Instances and larger instance types do not eliminate the cost of idle time.

Answer

Move the job to a larger instance type to finish faster.

Answer

Enable detailed monitoring and create a CloudWatch alarm to reboot the instance if CPU utilization is low.

Answer

Purchase a 1-year All Upfront Reserved Instance for the instance.

Question 13

A company runs an internal analytics application in a single AWS Region. A solutions architect is reviewing the Amazon RDS for MySQL deployment and finds a Multi-AZ DB instance with a standby in another Availability Zone, used only for failover. The application performs many read-heavy queries against the primary instance, driving up instance size and cost. The team wants to offload read traffic and reduce the primary instance size. Which change should the architect recommend?

Accepted Answer

Add RDS read replicas and direct read-heavy queries to them.. Adding RDS read replicas moves read-heavy queries onto separate instances, relieving the primary and enabling a smaller, cheaper primary instance. The Multi-AZ standby exists only for failover and cannot serve reads, so the architect should introduce read replicas rather than re-architecting the deployment or switching database engines.

Answer

Convert the deployment to a Multi-AZ DB cluster with two readable standbys.

Answer

Migrate the database to Amazon DynamoDB with on-demand capacity.

Answer

Enable RDS Performance Insights and rely on it to reduce query cost.

Question 14

A company runs a web application on Amazon EC2 instances in multiple Availability Zones. The application uses an Application Load Balancer and an Auto Scaling group. The company wants to reduce cost while maintaining high availability. The workload is steady and predictable, and the instances run continuously. Which two actions will reduce cost? (Choose two.)

Accepted Answer

Right-size the instances based on CloudWatch metrics to eliminate over-provisioned capacity.. For a steady, continuously running workload, the two most effective cost levers are purchasing commitments and right-sizing. Compute Savings Plans reduce the effective rate for the baseline usage, and right-sizing removes capacity that is not needed. High-availability features and load balancer choices should be preserved unless they are proven to be the primary cost driver.

Answer

Move the application to a single Availability Zone to reduce data transfer charges.

Answer

Enable termination protection on all instances to prevent accidental deletion.

Answer

Replace the Application Load Balancer with a Network Load Balancer to reduce hourly charges.

Question 15

A company runs a containerized microservices application on Amazon ECS with the Fargate launch type. The application experiences highly variable traffic, with long periods of low utilization and occasional sharp spikes. The company wants to minimize cost while ensuring the application can scale quickly during spikes. The tasks are stateless and can be restarted. Which combination of actions will meet these requirements MOST cost-effectively?

Accepted Answer

Use a mix of Fargate On-Demand for a baseline and Fargate Spot for additional capacity, with a target tracking scaling policy.. For variable traffic with occasional spikes, a baseline of On-Demand capacity combined with Spot for burst capacity balances reliability and cost. Target tracking scaling responds to actual demand, and stateless tasks make Spot interruptions acceptable. Using Spot for everything risks availability, while using On-Demand for everything forgoes savings.

Answer

Use Fargate Spot for all tasks and enable ECS deployment circuit breaker to replace interrupted tasks.

Answer

Use Fargate On-Demand for all tasks and configure a scheduled scaling policy to add tasks at known peak times.

Answer

Use Fargate Spot capacity for all tasks and configure a target tracking scaling policy based on CPU utilization.