SAA-C03 Design Cost-Optimized Architectures Practice Test 11 — 15 Questions

Question 1

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 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. This eliminates NAT data processing charges because traffic stays within the AWS backbone, reducing costs significantly for large data downloads.

Answer

S3 Object Lambda

Answer

AWS Shield Advanced

Answer

A larger NAT gateway

Question 2

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 design must avoid adding custom operational scripts.

Accepted Answer

DynamoDB on-demand capacity mode. DynamoDB on-demand capacity mode is ideal for unpredictable workloads with long idle periods and occasional spikes because it automatically scales to handle traffic without requiring any capacity planning or provisioning. You pay only for the reads and writes you actually perform, eliminating the cost of idle provisioned capacity and the operational overhead of managing scaling scripts or alarms.

Answer

Reserved capacity for maximum daily traffic

Answer

Provisioned capacity set for peak traffic

Answer

Global tables in every Region

Question 3

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.

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 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

Answer

Disable CloudTrail logging

Question 4

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 design must avoid adding custom operational scripts.

Accepted Answer

AWS Graviton-based instances after performance testing. Option C is correct because AWS Graviton-based instances (ARM architecture) offer up to 40% better price-performance compared to comparable x86 instances for many workloads. Since the marketing site 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 the OS and software can be recompiled for ARM natively.

Answer

Cross-Region data replication for all data

Answer

io2 Block Express volumes for all instances

Answer

Dedicated Hosts by default

Question 5

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

Answer

CloudWatch detailed monitoring on all instances

Answer

Route 53 health checks

Question 6

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. Option B is correct because 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

Answer

Disabling route tables

Answer

Moving all workloads to public subnets

Question 7

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

Answer

S3 Glacier Deep Archive

Answer

S3 Standard for all objects

Question 8

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.

Answer

AWS DataSync

Answer

AWS Shield

Answer

AWS Artifact

Question 9

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

Answer

S3 Glacier Flexible Retrieval for all files

Answer

EFS One Zone for analytics files

Question 10

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

Answer

Dedicated Hosts

Answer

Provisioned IOPS volumes

Question 11

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

Answer

Dedicated Instances

Answer

Spot Instances only

Question 12

A marketing site 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 design must avoid adding custom operational scripts.

Accepted Answer

S3 lifecycle policy that transitions objects to lower-cost storage classes over time. Option A is correct because S3 Lifecycle policies allow you to automatically transition objects from S3 Standard to lower-cost storage classes like S3 Standard-IA (Infrequent Access) after 30 days, then to S3 Glacier Deep Archive after one year, without custom scripts. This matches the access pattern: frequent queries for 30 days, rare access for a year, then long-term retention for compliance. The policy automates cost reduction by moving data to progressively cheaper storage as access frequency decreases.

Answer

Keep all logs in S3 Standard indefinitely

Answer

Use EBS snapshots for the logs

Answer

Move all logs immediately to S3 Glacier Deep Archive

Question 13

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

Answer

S3 Object Lambda

Answer

AWS Shield Advanced

Question 14

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.

Answer

Reserved capacity for maximum daily traffic

Answer

Provisioned capacity set for peak traffic

Answer

Global tables in every Region

Question 15

A internal reporting portal 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.

Accepted Answer

Delete unattached EBS volumes after verifying they are no longer needed. Option C is correct because deleting unattached EBS volumes directly reduces storage costs without impacting running instances, as these volumes are not in use. Option D is correct because snapshot lifecycle policies automate the deletion of obsolete snapshots, eliminating manual cleanup and reducing storage costs without custom scripts.

Answer

Disable CloudTrail logging

Answer

Stop all EC2 instances in the account