SAA-C03 Design Cost-Optimized Architectures Practice Test 12 — 15 Questions

Question 1

A test environment runs on x86 EC2 instances and uses open-source software with no architecture-specific licensing restriction. What should be evaluated to reduce compute cost? The design must avoid adding custom operational scripts.

Accepted Answer

AWS Graviton-based instances after performance testing. Option B is correct because AWS Graviton-based instances (ARM architecture) offer up to 40% better price-performance compared to x86 instances for many workloads. Since the environment uses open-source software with no architecture-specific licensing restrictions, migrating to Graviton after performance testing can significantly reduce compute costs without requiring custom operational scripts, as AWS provides native support for ARM-based instances.

Answer

Cross-Region data replication for all data

Answer

io2 Block Express volumes for all instances

Answer

Dedicated Hosts by default

Question 2

A media processing workflow uses CloudWatch Logs heavily. Retaining all debug logs forever is increasing costs. What should be configured? The design must avoid adding custom operational scripts.

Accepted Answer

CloudWatch Logs retention policies per log group. Option B is correct because CloudWatch Logs retention policies allow you to set a time-based expiration (e.g., 30 days) on log groups, automatically deleting old log events. This directly reduces storage costs without requiring custom scripts, as the retention policy is a native CloudWatch Logs feature configured per log group.

Answer

Route 53 health checks

Answer

CloudWatch detailed monitoring on all instances

Answer

AWS Config aggregation

Question 3

A dev sandbox currently uses two NAT gateways in each of three Availability Zones, but only one private subnet per AZ needs outbound internet access. What should the architect review first? The design must avoid adding custom operational scripts.

Accepted Answer

Whether one NAT gateway per AZ is sufficient for the required private subnets. Option D is correct because the question asks what the architect should review first to optimize costs while maintaining functionality. Using two NAT gateways per AZ when only one private subnet per AZ needs outbound internet access is redundant; a single NAT gateway per AZ can handle the traffic for all private subnets in that AZ. The design must avoid custom operational scripts, so the simplest review is to check if one NAT gateway per AZ is sufficient, which would reduce costs without breaking connectivity.

Answer

Disabling route tables

Answer

Replacing every NAT gateway with an internet gateway attached to private subnets

Answer

Moving all workloads to public subnets

Question 4

A log archive serves infrequently accessed user documents that must be available immediately when requested. Which S3 storage class is likely the best cost fit? The design must avoid adding custom operational scripts.

Accepted Answer

S3 Standard-IA or S3 One Zone-IA depending on resilience requirements. S3 Standard-IA or S3 One Zone-IA is the best cost fit because the workload involves infrequently accessed documents that require immediate retrieval. These storage classes offer lower storage costs than S3 Standard while maintaining low-latency access (milliseconds), and they avoid custom operational scripts since retrieval is automatic via standard S3 GET requests. The choice between Standard-IA and One Zone-IA depends on whether the data requires multi-AZ resilience or can tolerate a single-AZ failure.

Answer

Instance store volumes

Answer

S3 Standard for all objects

Answer

S3 Glacier Deep Archive

Question 5

A marketing site has EC2 instances that are oversized based on CPU, memory, and network utilisation. Which AWS service should identify rightsizing recommendations? The design must avoid adding custom operational scripts.

Accepted Answer

AWS Compute Optimizer. AWS Compute Optimizer analyzes historical utilization metrics (CPU, memory, network) of EC2 instances and generates rightsizing recommendations to reduce cost without compromising performance. It uses machine learning to identify over-provisioned resources and suggests instance type changes, all without requiring custom scripts or agents.

Answer

AWS Shield

Answer

AWS DataSync

Answer

AWS Artifact

Question 6

A risk simulation workload generates analytics files that are accessed unpredictably. Some files become hot again months later. The team wants automatic storage cost optimisation without retrieval delays. What should be used? The design must avoid adding custom operational scripts.

Accepted Answer

S3 Intelligent-Tiering. S3 Intelligent-Tiering automatically moves objects between access tiers (frequent, infrequent, and archive instant access) based on changing access patterns, with no retrieval delays for hot objects and no operational overhead. This matches the unpredictable access pattern where files become hot again months later, as Intelligent-Tiering monitors access at the object level and adjusts storage class without manual intervention or custom scripts.

Answer

Manual monthly review and object copying

Answer

S3 Glacier Flexible Retrieval for all files

Answer

EFS One Zone for analytics files

Question 7

A batch analytics job runs for several hours each night and can be interrupted and restarted. Which EC2 purchasing option should minimize cost? The architecture review board prefers a managed AWS-native control.

Accepted Answer

Spot Instances. Spot Instances are correct because the batch job is fault-tolerant (can be interrupted and restarted) and runs for several hours each night, making it an ideal candidate for Spot Instances, which offer up to 90% cost savings compared to On-Demand. AWS-managed services like EC2 Auto Scaling or Amazon EMR can automatically handle Spot Instance interruptions by replacing instances or checkpointing the job, aligning with the architecture review board's preference for a managed AWS-native control.

Answer

On-Demand Instances only

Answer

Dedicated Hosts

Answer

Provisioned IOPS volumes

Question 8

A production internal reporting portal runs continuously on EC2 with predictable usage for the next three years. The team wants a discount while retaining some instance-family flexibility. What should they buy? The architecture review board prefers a managed AWS-native control.

Accepted Answer

Compute Savings Plan. The Compute Savings Plan offers the largest discount (up to 66%) in exchange for a commitment to a consistent amount of compute usage (measured in $/hour) for a 1- or 3-year term, while retaining flexibility across instance families, regions, and compute services (EC2, Fargate, Lambda). This matches the requirement for a discount on predictable three-year usage with instance-family flexibility, and it is a managed AWS-native purchasing option.

Answer

Spot Instances only

Answer

Dedicated Instances

Answer

S3 Intelligent-Tiering

Question 9

A test environment stores logs in S3. Logs are queried for 30 days, rarely accessed for one year, and then retained for compliance. What should reduce storage cost? The architecture review board prefers a managed AWS-native control.

Accepted Answer

S3 lifecycle policy that transitions objects to lower-cost storage classes over time. Option C is correct because S3 Lifecycle policies allow you to automate the transition of objects from S3 Standard to lower-cost storage classes like S3 Standard-IA (after 30 days) and then to S3 Glacier Deep Archive (after one year) for long-term compliance. This matches the access pattern of frequent queries for 30 days, rare access for a year, and then retention-only, minimizing storage costs without manual intervention.

Answer

Keep all logs in S3 Standard indefinitely

Answer

Move all logs immediately to S3 Glacier Deep Archive

Answer

Use EBS snapshots for the logs

Question 10

A media processing workflow in private subnets downloads large amounts of data from S3 through a NAT gateway. NAT data processing charges are high. What should the architect use to reduce cost? The architecture review board prefers a managed AWS-native control.

Accepted Answer

Gateway VPC endpoint for Amazon S3. A Gateway VPC endpoint for Amazon S3 allows instances in private subnets to access S3 directly over the AWS network without traversing a NAT gateway, eliminating NAT data processing charges. This is a managed AWS-native control that meets the architecture review board's preference, as it uses AWS PrivateLink and does not require any changes to the S3 bucket or client configuration beyond route table updates.

Answer

S3 Object Lambda

Answer

AWS Shield Advanced

Answer

A larger NAT gateway

Question 11

A dev sandbox has unpredictable DynamoDB traffic with long idle periods and occasional spikes. Which capacity mode should minimize operational overhead and avoid paying for idle provisioned capacity? The architecture review board prefers a managed AWS-native control.

Accepted Answer

DynamoDB on-demand capacity mode. DynamoDB on-demand capacity mode (Option C) is ideal for unpredictable traffic with long idle periods and spikes because it automatically scales to handle workload demands without requiring any capacity planning. You pay only for the reads and writes you perform, eliminating the cost of idle provisioned capacity and the operational overhead of managing scaling thresholds.

Answer

Reserved capacity for maximum daily traffic

Answer

Provisioned capacity set for peak traffic

Answer

Global tables in every Region

Question 12

A log archive has old unattached EBS volumes and many stale snapshots. Which two actions reduce storage cost without affecting running instances? The architecture review board prefers a managed AWS-native control.

Accepted Answer

Delete unattached EBS volumes after verifying they are no longer needed. Option C is correct because deleting unattached EBS volumes eliminates storage costs for volumes that are not in use, and since they are not attached to any running instance, this action does not affect running instances. Option D is correct because applying snapshot lifecycle policies (e.g., using Amazon Data Lifecycle Manager) automates the expiration of obsolete snapshots, reducing storage costs without impacting running instances. Both actions are managed AWS-native controls, aligning with the architecture review board's preference.

Answer

Stop all EC2 instances in the account

Answer

Disable CloudTrail logging

Question 13

A marketing site runs on x86 EC2 instances and uses open-source software with no architecture-specific licensing restriction. What should be evaluated to reduce compute cost? The architecture review board prefers a managed AWS-native control.

Accepted Answer

AWS Graviton-based instances after performance testing. Option C is correct because AWS Graviton-based instances use ARM-based custom processors that offer up to 40% better price-performance compared to comparable x86 instances for many workloads. Since the marketing site runs open-source software with no architecture-specific licensing restrictions, migrating to Graviton after performance testing can significantly reduce compute costs while leveraging a managed AWS-native control (e.g., EC2 Auto Scaling groups with Graviton instance types).

Answer

Cross-Region data replication for all data

Answer

io2 Block Express volumes for all instances

Answer

Dedicated Hosts by default

Question 14

A risk simulation workload uses CloudWatch Logs heavily. Retaining all debug logs forever is increasing costs. What should be configured? The architecture review board prefers a managed AWS-native control.

Accepted Answer

CloudWatch Logs retention policies per log group. CloudWatch Logs retention policies allow you to set per-log-group expiration rules (e.g., 30 days, 90 days) to automatically delete old log events, directly reducing storage costs for debug logs that are no longer needed. This is a managed, AWS-native control that requires no custom scripts or external tools, aligning with the architecture review board's preference.

Answer

AWS Config aggregation

Answer

CloudWatch detailed monitoring on all instances

Answer

Route 53 health checks

Question 15

A batch analytics job currently uses two NAT gateways in each of three Availability Zones, but only one private subnet per AZ needs outbound internet access. What should the architect review first? The architecture review board prefers a managed AWS-native control.

Accepted Answer

Whether one NAT gateway per AZ is sufficient for the required private subnets. The architecture currently uses two NAT gateways per AZ, but only one private subnet per AZ requires outbound internet access. Since a single NAT gateway in an AZ can serve all private subnets in that AZ via the route table, the first step is to verify whether one NAT gateway per AZ is sufficient for the required throughput and availability. This aligns with cost optimization by eliminating unnecessary NAT gateway hourly charges and data processing fees.

Answer

Replacing every NAT gateway with an internet gateway attached to private subnets

Answer

Disabling route tables

Answer

Moving all workloads to public subnets