SAA-C03 Design Cost-Optimized Architectures Practice Test 8 — 15 Questions

Question 1

A log archive has old unattached EBS volumes and many stale snapshots. Which two actions reduce storage cost without affecting running instances? The design must avoid adding custom operational scripts.

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

Accepted Answer

Delete unattached EBS volumes after verifying they are no longer needed. 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 automates the deletion of obsolete snapshots, reducing storage costs without requiring custom scripts or impacting running instances.

Answer

Stop all EC2 instances in the account

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Disable CloudTrail logging

Question 2

A risk simulation workload 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. 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 without custom scripts. Since the workload uses CloudWatch Logs heavily and retains debug logs forever, configuring a retention policy on each log group is the simplest, most cost-effective solution that requires no operational overhead.

Answer

AWS Config aggregation

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CloudWatch detailed monitoring on all instances

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Route 53 health checks

Question 3

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 design must avoid adding custom operational scripts.

Accepted Answer

Whether one NAT gateway per AZ is sufficient for the required private subnets. The current setup uses two NAT gateways per AZ, which is likely over-provisioned and incurs unnecessary costs. Since only one private subnet per AZ requires outbound internet access, a single NAT gateway per AZ is typically sufficient to handle the traffic, and this is the first cost-optimization step to review before making other changes.

Answer

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

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Disabling route tables

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Moving all workloads to public subnets

Question 4

A internal reporting portal 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 data is infrequently accessed but requires immediate availability when requested. These storage classes offer lower storage costs than S3 Standard while providing low-latency retrieval (milliseconds), avoiding the retrieval delays or operational overhead of archival tiers. The choice between Standard-IA and One Zone-IA depends on resilience needs: Standard-IA stores data across multiple AZs, while One Zone-IA stores data in a single AZ at a lower cost.

Answer

Instance store volumes

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S3 Glacier Deep Archive

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S3 Standard for all objects

Question 5

A test environment 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 uses machine learning to analyze historical utilization metrics (CPU, memory, network) and generates rightsizing recommendations for EC2 instances, including instance type changes and downsizing opportunities. It operates without requiring custom scripts, as it leverages existing CloudWatch metrics and optionally the Compute Optimizer agent for enhanced memory and disk metrics.

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AWS DataSync

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AWS Shield

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AWS Artifact

Question 6

A media processing workflow 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 the service monitors access and adjusts storage class without custom scripts.

Answer

Manual monthly review and object copying

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S3 Glacier Flexible Retrieval for all files

Answer

EFS One Zone for analytics files

Question 7

A dev sandbox runs for several hours each night and can be interrupted and restarted. Which EC2 purchasing option should minimize cost? The design must avoid adding custom operational scripts.

Accepted Answer

Spot Instances. Spot Instances (B) are ideal for fault-tolerant, interruptible workloads like a nightly dev sandbox because they offer significant cost savings (up to 90% off On-Demand) in exchange for being reclaimable by AWS with a 2-minute warning. Since the sandbox can be interrupted and restarted, and the design avoids custom scripts, Spot Instances can leverage native AWS features like hibernation or automatic recovery to resume work without manual intervention.

Answer

On-Demand Instances only

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Dedicated Hosts

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Provisioned IOPS volumes

Question 8

A production log archive 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 design must avoid adding custom operational scripts.

Accepted Answer

Compute Savings Plan. The Compute Savings Plan (C) 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 still allowing flexibility across instance families, sizes, OS, tenancy, and regions. This matches the predictable three-year workload and the requirement for instance-family flexibility without custom scripts.

Answer

S3 Intelligent-Tiering

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Dedicated Instances

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Spot Instances only

Question 9

A risk simulation workload 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 design must avoid adding custom operational scripts.

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 the most cost-effective and operationally simple solution because it requires no custom scripts and no changes to routing beyond adding the endpoint.

Answer

A larger NAT gateway

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S3 Object Lambda

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AWS Shield Advanced

Question 10

A batch analytics job 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 design must avoid adding custom operational scripts.

Accepted Answer

DynamoDB on-demand capacity mode. DynamoDB on-demand capacity mode automatically scales to handle unpredictable traffic spikes and idle periods without requiring any capacity planning or management. It charges only for the reads and writes you perform, eliminating the cost of idle provisioned capacity and avoiding the need for custom scripts to adjust capacity.

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Reserved capacity for maximum daily traffic

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Provisioned capacity set for peak traffic

Answer

Global tables in every Region

Question 11

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. 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 12

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

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AWS DataSync

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AWS Artifact

Question 13

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

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Dedicated Instances

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S3 Intelligent-Tiering

Question 14

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. 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

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Move all logs immediately to S3 Glacier Deep Archive

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Use EBS snapshots for the logs

Question 15

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