SAA-C03 Design Cost-Optimized Architectures Practice Test 7 — 15 Questions

Question 1

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?

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 must be available immediately when requested. These storage classes offer low-latency retrieval (milliseconds) at a lower storage cost than S3 Standard, with the trade-off of a retrieval fee. The choice between Standard-IA and One Zone-IA depends on whether the application requires resilience against Availability Zone failures.

Answer

Instance store volumes

Answer

S3 Glacier Deep Archive

Answer

S3 Standard for all objects

Question 2

A test environment has EC2 instances that are oversized based on CPU, memory, and network utilisation. Which AWS service should identify rightsizing recommendations?

Accepted Answer

AWS Compute Optimizer. AWS Compute Optimizer uses machine learning to analyze historical utilization metrics (CPU, memory, network, and storage) and provides rightsizing recommendations for EC2 instances, including over-provisioned resources. It helps reduce costs by suggesting instance types or sizes that better match actual workload demands.

Answer

AWS DataSync

Answer

AWS Shield

Answer

AWS Artifact

Question 3

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?

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. This is ideal for unpredictable access where some files become hot again months later, as it optimizes storage costs without manual intervention or retrieval latency.

Answer

Manual monthly review and object copying

Answer

S3 Glacier Flexible Retrieval for all files

Answer

EFS One Zone for analytics files

Question 4

A dev sandbox runs for several hours each night and can be interrupted and restarted. Which EC2 purchasing option should minimize cost?

Accepted Answer

Spot Instances. Spot Instances can be interrupted and restarted, making them ideal for fault-tolerant workloads like a nightly dev sandbox. They offer significant cost savings (up to 90% off On-Demand) because they use spare AWS EC2 capacity, which aligns perfectly with the scenario's tolerance for interruption.

Answer

On-Demand Instances only

Answer

Dedicated Hosts

Answer

Provisioned IOPS volumes

Question 5

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?

Accepted Answer

S3 lifecycle policy that transitions objects to lower-cost storage classes over time. An S3 Lifecycle policy automates the transition of objects from S3 Standard (frequently accessed) to lower-cost storage classes like S3 Standard-IA (infrequent access) after 30 days, then to S3 Glacier Deep Archive for long-term compliance retention. This matches the access pattern: frequent queries for 30 days, rare access for a year, then archival storage, minimizing cost without manual intervention.

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 6

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?

Accepted Answer

Gateway VPC endpoint for Amazon S3. A Gateway VPC endpoint for Amazon S3 allows instances in private subnets to access S3 directly via the AWS network, bypassing the NAT gateway entirely. This eliminates NAT data processing charges (per GB) for S3 traffic, which can be significant for large data downloads. The endpoint is free to use and routes traffic through AWS's private backbone, not the internet.

Answer

A larger NAT gateway

Answer

S3 Object Lambda

Answer

AWS Shield Advanced

Question 7

A internal reporting portal has old unattached EBS volumes and many stale snapshots. Which two actions reduce storage cost without affecting running instances?

Accepted Answer

Delete unattached EBS volumes after verifying they are no longer needed. Unattached EBS volumes incur storage costs without providing any benefit to running instances. Deleting them after verifying they are no longer needed directly reduces these costs without affecting any active EC2 instances.

Answer

Disable CloudTrail logging

Answer

Stop all EC2 instances in the account

Question 8

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?

Accepted Answer

AWS Graviton-based instances after performance testing. AWS Graviton-based instances (e.g., M6g, C6g) use Arm-based custom AWS silicon, offering up to 40% better price-performance compared to comparable x86 instances for many workloads. Since the test environment runs open-source software with no architecture-specific licensing restrictions, migrating to Graviton after performance testing can significantly reduce compute costs without compatibility issues.

Answer

Cross-Region data replication for all data

Answer

io2 Block Express volumes for all instances

Answer

Dedicated Hosts by default

Question 9

A media processing workflow uses CloudWatch Logs heavily. Retaining all debug logs forever is increasing costs. What should be configured?

Accepted Answer

CloudWatch Logs retention policies per log group. CloudWatch Logs retention policies per log group allow you to set an expiration time (e.g., 30 days) after which log events are automatically deleted. This directly reduces storage costs by preventing debug logs from accumulating indefinitely, without affecting other monitoring or routing functions.

Answer

Route 53 health checks

Answer

CloudWatch detailed monitoring on all instances

Answer

AWS Config aggregation

Question 10

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?

Accepted Answer

Whether one NAT gateway per AZ is sufficient for the required private subnets. The question states that only one private subnet per AZ needs outbound internet access, so using two NAT gateways per AZ is likely over-provisioned and costly. The architect should first review whether one NAT gateway per AZ is sufficient, as NAT gateways are billed per hour and per gigabyte of data processed, and reducing from two to one per AZ can cut costs without sacrificing availability. This aligns with the cost-optimized design principle of right-sizing resources to actual demand.

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 11

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?

Accepted Answer

S3 Intelligent-Tiering. S3 Intelligent-Tiering is the correct choice because it automatically moves objects between access tiers (frequent, infrequent, and archive instant access) based on changing access patterns, without any retrieval delays. This handles the unpredictable access described—files that become hot again months later—by keeping them in the archive instant access tier until access resumes, then promoting them instantly. It optimizes storage costs automatically without manual intervention or cold retrieval waits.

Answer

Manual monthly review and object copying

Answer

S3 Glacier Flexible Retrieval for all files

Answer

EFS One Zone for analytics files

Question 12

A batch analytics job 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 are ideal for fault-tolerant, interruptible batch workloads because they offer significant cost savings (up to 90% off On-Demand pricing) by using spare EC2 capacity. Since the job can be interrupted and restarted, it can handle Spot Instance reclaimations without requiring custom operational scripts—AWS handles the interruption notification and automatic instance termination, and the job's restart logic can be built into the application or orchestration layer (e.g., AWS Batch).

Answer

On-Demand Instances only

Answer

Dedicated Hosts

Answer

Provisioned IOPS volumes

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 design must avoid adding custom operational scripts.

Accepted Answer

Compute Savings Plan. Compute Savings Plans offer the lowest prices on EC2 instance usage (up to 66% off On-Demand) in exchange for a 1- or 3-year commitment, while allowing flexibility across instance families, sizes, OS, and regions. This matches the requirement for a discount on predictable, continuous usage without locking into a specific instance type, and requires no custom scripts.

Answer

Spot Instances only

Answer

Dedicated Instances

Answer

S3 Intelligent-Tiering

Question 14

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 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 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