SAA-C03 Design Cost-Optimized Architectures Practice Test 16 — 15 Questions

Question 1

A company is migrating its on-premises workloads to AWS and wants to optimize costs. Which three strategies should the company implement to achieve a cost-optimized architecture? (Choose three.)

Accepted Answer

Use Spot Instances for fault-tolerant, flexible workloads to achieve significant cost savings.. Reserved Instances or Savings Plans provide significant discounts (up to 72%) over On-Demand pricing for predictable workloads by committing to a specific usage term (1 or 3 years). This directly reduces compute costs for steady-state applications, making it a core cost-optimization strategy.

Answer

Deploy all resources in a single Availability Zone to minimize data transfer costs.

Answer

Provision additional EC2 instances to handle peak load at all times, ensuring maximum performance.

Answer

Store all data in Amazon S3 Standard storage class to avoid any data retrieval costs.

Question 2

A solutions architect is designing a cost-optimized data storage solution for a large dataset that is accessed infrequently but must be retained for compliance for 7 years. Which three actions should the architect take to minimize costs? (Choose three.)

Accepted Answer

Enable S3 Intelligent-Tiering to automatically move data between access tiers based on usage patterns.. Amazon S3 lifecycle policies allow you to define rules that automatically transition objects to colder storage tiers like S3 Glacier Deep Archive after a specified period. This approach minimizes costs by keeping data in S3 Standard only for the initial 30 days when it might be accessed, then moving it to the lowest-cost storage class for the remaining compliance period. S3 Intelligent-Tiering automatically optimizes costs by monitoring access patterns and moving data between frequent, infrequent, and archive access tiers without manual intervention. S3 Object Lock in compliance mode prevents any user, including the root user, from deleting or overwriting objects during the retention period, ensuring regulatory compliance.

Answer

Store all data in Amazon EBS gp2 volumes attached to an EC2 instance for low-latency access.

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Replicate all data to a second AWS Region using S3 Cross-Region Replication to ensure durability.

Answer

Store the data in Amazon S3 Glacier Deep Archive immediately after creation.

Question 3

A company is running a production web application on Amazon EC2 instances behind an Application Load Balancer (ALB). The workload has predictable traffic spikes during business hours and low traffic at night. The current architecture uses On-Demand EC2 instances, leading to high costs. The company wants to reduce costs without sacrificing availability or performance. Which three of the following strategies would help achieve this goal? (Choose three.)

Accepted Answer

Use Auto Scaling with a mixed instances policy that includes On-Demand and Spot Instances.. Purchasing Reserved Instances for the baseline 24/7 capacity provides a significant discount (up to 72%) compared to On-Demand pricing, directly reducing costs for the always-running portion of the workload. This strategy is correct because it matches the predictable, steady-state traffic component without sacrificing availability or performance.

Answer

Add Spot Instances for the entire workload during peak hours.

Answer

Migrate to AWS Lambda for all web application traffic.

Answer

Consolidate all instances into a single larger instance to reduce overhead.

Question 4

A company runs a stateless web application on a fleet of six On-Demand EC2 instances behind an Application Load Balancer. The instances are spread across three Availability Zones in a single AWS Region and run 24/7. The workload is steady and predictable, and the company wants to reduce compute costs without changing the application architecture or reducing availability. The company is willing to commit to a one-year term. Which two actions will reduce the EC2 compute cost for this workload? (Choose two.)

Accepted Answer

Purchase a one-year Standard Reserved Instance for each of the six running instances in the same instance family and Region.. For steady, predictable, always-on compute, commitment-based discounts are the correct lever. Compute Savings Plans and Standard Reserved Instances both convert On-Demand hourly pricing into a lower committed rate for a one-year term, satisfying the cost goal while preserving the multi-AZ, always-available design. Spot capacity and monitoring changes do not meet the availability requirement or do not change the compute rate.

Answer

Enable detailed monitoring on all instances and configure an Auto Scaling target tracking policy at 40% CPU.

Answer

Replace the On-Demand instances with Spot Instances and let the Auto Scaling group replace any interrupted capacity.

Answer

Move the instances into a placement group and enable cluster networking between them.

Question 5

A company stores nightly database backup files in an Amazon S3 bucket. Each backup is about 50 GB, and the files are written once and never modified. Regulatory policy requires that every backup be retained for exactly seven years, after which it may be deleted. Retrieval of a backup for an audit is extremely rare and the company can tolerate a retrieval time of up to 12 hours. Which S3 storage class is the MOST cost-effective choice for these backups?

Accepted Answer

S3 Glacier Deep Archive. The backups are immutable, retained for a fixed multi-year period, and almost never retrieved, with a retrieval tolerance of up to 12 hours. S3 Glacier Deep Archive is purpose-built for exactly this pattern and offers the lowest storage cost among S3 classes, so it satisfies both the compliance retention requirement and the cost-optimization goal without needing frequent access.

Answer

S3 One Zone-IA

Answer

S3 Intelligent-Tiering

Answer

S3 Standard

Question 6

A company runs an internal analytics application on Amazon RDS for PostgreSQL. The database is used heavily from 08:00 to 18:00 on weekdays, but outside those hours it receives almost no queries. The company must keep the database available at all times and cannot tolerate downtime during business hours. The team wants to reduce the cost of running this database. Which approach is the MOST cost-effective while meeting the availability requirement?

Accepted Answer

Migrate the workload to Aurora Serverless v2 with a minimum capacity that scales down during idle periods.. The workload has a sharp, predictable busy period and long idle windows, yet the database must remain available at all times. Aurora Serverless v2 capacity scales down during idle periods without stopping the database, so the company pays far less during the quiet hours while preserving continuous availability, which is the most cost-effective option that satisfies the constraint.

Answer

Convert the DB instance to a Multi-AZ deployment and purchase a Reserved Instance for the primary instance.

Answer

Enable Aurora Auto Scaling with a reader endpoint and route all read queries to the reader.

Answer

Stop the DB instance every evening and start it again each weekday morning.

Question 7

A data analytics team runs an Amazon EMR cluster for 2 hours every weekday morning to process a daily batch. The cluster must be fully available during that window, and the team wants the lowest possible compute cost. The jobs are stateless and can be re-run if a node fails. Which configuration should a solutions architect recommend?

Accepted Answer

Provision the EMR cluster with On-Demand Instances for the master node and Spot Instances for task nodes.. The workload is a short, recurring, fault-tolerant batch job, so the best cost strategy is to combine a stable On-Demand master with Spot task nodes that can be reclaimed and restarted. This preserves cluster availability while taking advantage of Spot's lower pricing. Long-term commitments and Dedicated Hosts are poor fits because the compute is neither continuous nor compliance-driven.

Answer

Provision the EMR cluster entirely with Dedicated Hosts to guarantee physical isolation and predictable pricing.

Answer

Provision the EMR cluster with On-Demand Instances for all node types and enable automatic scaling.

Answer

Provision the EMR cluster with Reserved Instances for a 3-year term to lock in the lowest hourly rate.

Question 8

A company runs a steady-state web application on a fixed number of Amazon EC2 instances that have been running continuously for over a year. The workload is predictable and will remain in production for at least three more years. Management wants to reduce compute cost without changing the architecture. Which purchasing option should a solutions architect recommend?

Accepted Answer

Purchase a 3-year Compute Savings Plan with a partial upfront payment for the steady EC2 usage.. For predictable, long-running EC2 usage, a Compute Savings Plan provides a lower effective hourly rate in exchange for a term commitment. It is flexible across instance families and Regions, so it reduces cost without requiring the application to change. Spot risks interruption, On-Demand forgoes discounts, and Dedicated Instances raise cost rather than lower it.

Answer

Use On-Demand Instances and enable detailed monitoring to improve utilization visibility.

Answer

Move the application to Dedicated Instances to obtain volume discounts on the hourly rate.

Answer

Convert the instances to Spot Instances to take advantage of unused EC2 capacity.

Question 9

A financial services company stores regulatory documents in an Amazon S3 bucket. The documents are accessed frequently for the first 90 days, then almost never, but must remain immediately retrievable for seven years. Retrieval latency of a few minutes is unacceptable, and the company wants the lowest storage cost that still meets the access requirement. Which S3 storage class should a solutions architect recommend?

Accepted Answer

S3 Glacier Instant Retrieval. The requirement is long-term, low-cost storage with immediate retrieval and no minutes-long latency. S3 Glacier Instant Retrieval provides millisecond access at a lower storage cost than S3 Standard-IA, making it the best fit for rarely accessed documents retained for years. A lifecycle rule can move objects from S3 Standard to Glacier Instant Retrieval after the active 90-day period.

Answer

S3 Glacier Flexible Retrieval

Answer

S3 One Zone-Infrequent Access (S3 One Zone-IA)

Answer

S3 Standard-Infrequent Access (S3 Standard-IA)

Question 10

A digital agency runs a web application on a fleet of Amazon EC2 instances behind an Application Load Balancer. Traffic is steady and predictable during business hours but drops to near zero overnight and on weekends. The operations team wants to reduce compute costs without impacting availability during peak periods. They cannot modify the application code and must keep the same instance types. What should a solutions architect recommend?

Accepted Answer

Create an Auto Scaling group with a scheduled scaling policy that scales the desired capacity up before business hours and down after hours.. The workload has a predictable daily and weekly pattern, so the most direct cost control is to align capacity with demand. A scheduled scaling policy changes desired capacity at known times, terminating instances when traffic is near zero and adding them back before the peak. This avoids paying for idle capacity while keeping the application available when users need it, and it requires no application changes.

Answer

Enable burstable T3 instances and rely on CPU credits to absorb the peak traffic periods.

Answer

Switch the fleet to Spot Instances and configure the Auto Scaling group to maintain the same desired capacity at all times.

Answer

Purchase a 1-year Standard Reserved Instance for each instance and leave the fleet running 24/7.

Question 11

A company runs a stateless web tier on a fleet of On-Demand EC2 instances behind an Application Load Balancer. Traffic is steady and predictable, and the team has committed to running this tier for the next three years with no planned architectural changes. Management wants the lowest possible compute cost while preserving the ability to change instance families during the term if a better price-performance option emerges. Which purchasing approach best meets these requirements?

Accepted Answer

Purchase a 3-year Compute Savings Plan with a committed hourly spend.. A Compute Savings Plan is the right choice because it discounts a committed hourly spend across any EC2 instance family, size, and Region, plus Lambda and Fargate. That flexibility directly supports the requirement to change instance families during the three-year term, unlike a Standard Reserved Instance or an EC2 Instance Savings Plan, which are tied to a specific family or Region. Spot capacity is cheaper but cannot guarantee availability for a steady production tier.

Answer

Run the fleet on Spot Instances with a capacity-optimized allocation strategy.

Answer

Purchase a 3-year EC2 Instance Savings Plan scoped to the current instance family and Region.

Answer

Purchase a 3-year Standard Reserved Instance for each instance in the fleet.

Question 12

A company runs a microservices application on Amazon ECS with AWS Fargate. The tasks run continuously, and the company has committed to a 3-year term. The team wants to reduce Fargate compute cost while keeping the same task definitions and architecture. Which action should a solutions architect take?

Accepted Answer

Purchase a Compute Savings Plan to cover the Fargate vCPU and memory usage.. Compute Savings Plans cover Fargate usage and provide a discount in exchange for a term commitment, so they lower the vCPU and memory rate without changing task definitions or the ECS architecture. Fargate Spot and EC2 Spot introduce interruption risk unsuitable for continuously running services, and resizing task resources changes the workload rather than the pricing model.

Answer

Reduce the task CPU and memory values in the task definition to lower the Fargate rate.

Answer

Convert the Fargate tasks to EC2 launch type with Spot Instances.

Answer

Enable Fargate Spot for all tasks to obtain the lowest possible compute rate.

Question 13

A retail company runs a stateless web tier on a fleet of On-Demand EC2 instances behind an Application Load Balancer. Traffic is steady and predictable throughout the year, and the team has committed to running this exact instance family and Region for at least the next three years. Leadership wants to reduce compute cost as much as possible while keeping the ability to change instance size within the same family. Which purchasing option should the solutions architect recommend?

Accepted Answer

A 3-year EC2 Instance Savings Plan with the All Upfront payment option. The workload is steady, long-lived, and already pinned to one instance family and Region, which is exactly the profile that EC2 Instance Savings Plans reward most heavily. Committing for three years with All Upfront yields the maximum discount, and the plan continues to allow size changes within the family, satisfying the flexibility requirement that rules out a size-locked reservation.

Answer

Spot Instances with a capacity-optimized allocation strategy

Answer

A 3-year Standard Reserved Instance for a specific instance size

Answer

A 3-year Compute Savings Plan with the No Upfront payment option

Question 14

A financial services company stores monthly regulatory reports in an Amazon S3 bucket. The reports are accessed frequently for the first 60 days after creation for audits and internal review. After that period, they are almost never accessed but must be retained for seven years and retrieved within 12 hours if a regulator requests them. The compliance team requires that the objects remain in a single bucket and that retrieval costs be minimized. Which storage solution meets these requirements MOST cost-effectively?

Accepted Answer

Apply a lifecycle policy that transitions objects to S3 Glacier Flexible Retrieval after 60 days.. The objects are hot for 60 days and then cold for years, with a retrieval-time requirement measured in hours rather than milliseconds. A lifecycle transition to S3 Glacier Flexible Retrieval after 60 days matches that pattern: it lowers storage cost for the long retention period and its standard retrieval completes well within 12 hours. Keeping everything in a single bucket is supported because lifecycle rules operate within the bucket.

Answer

Use S3 Intelligent-Tiering and let it move objects between frequent and infrequent access tiers automatically.

Answer

Keep all objects in S3 Standard and rely on S3 Versioning to reduce storage charges over time.

Answer

Apply a lifecycle policy that transitions objects to S3 Glacier Instant Retrieval after 60 days.

Question 15

A retail company runs an e-commerce platform on a fleet of Amazon EC2 instances behind an Application Load Balancer. Traffic follows a predictable pattern: high during business hours and very low overnight. The operations team wants to reduce EC2 costs without affecting availability during peak hours. The instances currently run continuously and are managed by an Auto Scaling group with a minimum capacity of 4 and a maximum of 20. Which solution will meet these requirements MOST cost-effectively?

Accepted Answer

Configure a scheduled scaling action on the Auto Scaling group to reduce the desired capacity during off-peak hours and increase it before peak hours.. For workloads with a predictable daily or weekly traffic pattern, scheduled scaling is the most direct way to align capacity with demand. It reduces the number of running instances during known low-traffic periods without waiting for a metric-based policy to react. Reserved Instances or target tracking do not eliminate the cost of idle overnight capacity in this scenario.

Answer

Enable detailed monitoring on all instances and create a target tracking scaling policy based on CPU utilization.

Answer

Purchase 4 Standard Reserved Instances for a 3-year term and let the Auto Scaling group launch On-Demand instances beyond that baseline.

Answer

Replace the Auto Scaling group with a larger number of smaller instances to improve granularity of scaling.