SAA-C03 Design Cost-Optimized Architectures Practice Test 14 — 15 Questions

Question 1

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 design must avoid adding custom operational scripts.

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

Accepted Answer

S3 lifecycle policy that transitions objects to lower-cost storage classes over time. S3 lifecycle policies automate the transition of objects between storage classes based on age, allowing logs to move from S3 Standard (for frequent querying) to S3 Standard-IA or S3 One Zone-IA (for rare access), and eventually to S3 Glacier Deep Archive (for long-term compliance retention). This reduces storage cost without custom scripts, aligning with the requirement to avoid operational overhead.

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 2

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 3

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 4

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. 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 5

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. 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 6

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 7

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

Answer

Disabling route tables

Answer

Moving all workloads to public subnets

Question 8

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 9

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 10

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 11

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 12

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. 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 13

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 14

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. 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 15

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