SAA-C03 Design High-Performing Architectures Practice Test 4 — 15 Questions

Question 1

Based on the exhibit, which design change is the best way to reduce the observed read latency for this DynamoDB-backed service?

Accepted Answer

Add a DynamoDB Accelerator (DAX) cluster in front of the table and send repeated read traffic through it.. Adding a DynamoDB Accelerator (DAX) cluster in front of the table reduces read latency by providing an in-memory cache for repeated read traffic. DAX delivers microsecond response times for eventually consistent reads, which directly addresses the observed latency issue without requiring application-level caching or table redesign.

Answer

Increase the on-demand table limits so DynamoDB can automatically absorb more traffic.

Answer

Create a global secondary index on tenantId to distribute the load across more partitions.

Answer

Move the dashboard data into S3 and use Lambda functions to read it on demand.

Question 2

A media platform serves global users through Amazon CloudFront and an S3 origin. Match each requirement on the left to the CloudFront configuration or behavior on the right.

Question 3

Based on the exhibit, which storage choice best matches the workload requirements?

Accepted Answer

Use instance store NVMe for the temporary processing workspace.. Instance store NVMe volumes provide temporary, high-performance block storage directly attached to the EC2 host. For a temporary processing workspace where data does not need to persist beyond the instance lifecycle, instance store offers the lowest latency and highest throughput, making it the best match for the workload requirements.

Answer

Use io2 EBS volumes because they provide the highest durable block storage performance.

Answer

Use Amazon EFS for the workspace so the temporary files survive instance replacement.

Answer

Use S3 as the working directory and read and write the intermediate files directly there.

Question 4

A company runs a stateless web API on Amazon EC2 behind an Application Load Balancer. The team notices that during business hours, the ALB starts queueing requests and the average request latency rises. They want to scale out quickly and reliably based on demand, not CPU alone. Which Auto Scaling approach best matches this requirement?

Accepted Answer

Use target tracking scaling based on ALB request count per target.. Target tracking scaling based on ALB request count per target directly aligns with the requirement to scale out based on demand (request queuing and latency) rather than CPU alone. This policy automatically adjusts the Auto Scaling group size to maintain a target value for the average number of requests per instance, which is a more reliable indicator of load for a stateless web API than CPU utilization.

Answer

Use a fixed-size Auto Scaling group and increase capacity manually once per hour.

Answer

Scale based only on EC2 instance memory utilization, regardless of load.

Answer

Use step scaling with a single threshold on average network-in bytes.

Question 5

A company serves mostly static images and JavaScript files from an origin in one AWS Region. They want to reduce origin load and improve global performance. Which change most directly increases cache-hit ratio for static assets while avoiding stale content?

Accepted Answer

Use versioned file names (e.g., app.abc123.js) and configure a long TTL with appropriate revalidation behavior.. Option B is correct because using versioned file names (e.g., app.abc123.js) allows you to set a long Cache-Control max-age TTL (e.g., one year) without risking stale content. When the file changes, the new version gets a new URL, so clients and edge caches immediately fetch the fresh object, maximizing cache hits for unchanged assets while avoiding stale content.

Answer

Set Cache-Control headers on the origin to always be no-cache so clients revalidate frequently.

Answer

Disable query string forwarding so all URLs without query strings share one cached object even when content differs.

Answer

Forward all headers, including cookies, to maximize personalization in edge cached responses.

Question 6

A company runs a stateless application tier behind an Application Load Balancer. Match each observed scaling pattern on the left to the best Auto Scaling strategy or metric on the right.

Question 7

A company runs a stateless web API on Amazon EC2 behind an Application Load Balancer. The team notices that during business hours, the ALB starts queueing requests and the average request latency rises. They want to scale out quickly and reliably based on demand, not CPU alone. Which Auto Scaling approach best matches this requirement?

Accepted Answer

Use target tracking scaling based on ALB request count per target.. Option B is correct because target tracking scaling based on ALB request count per target directly measures the load on each instance, allowing the Auto Scaling group to add or remove instances to maintain a target value. This approach scales out quickly and reliably based on actual demand (request queuing and latency), not just CPU, which aligns with the requirement to respond to rising latency and queueing during business hours.

Answer

Use a fixed-size Auto Scaling group and increase capacity manually once per hour.

Answer

Scale based only on EC2 instance memory utilization, regardless of load.

Answer

Use step scaling with a single threshold on average network-in bytes.

Question 8

Based on the exhibit, which change best reduces latency during peak traffic without overprovisioning the fleet?

Accepted Answer

Change the Auto Scaling policy to target tracking on ALB RequestCountPerTarget.. Option B is correct because using a target tracking scaling policy on ALB RequestCountPerTarget dynamically adjusts the fleet size based on the actual load per instance, ensuring that capacity scales with demand during peak traffic without manual intervention or overprovisioning. This approach directly addresses latency caused by high request rates per instance by maintaining a target request count, which reduces response time without adding unnecessary instances during off-peak periods.

Answer

Replace the instances with a larger instance family so each server has more headroom.

Answer

Use scheduled scaling to add instances only during the business hours peak window.

Answer

Replace the ALB with a Network Load Balancer to reduce request latency.

Question 9

Based on the exhibit, which storage choice best matches the workload requirements?

Accepted Answer

Use instance store NVMe for the temporary processing workspace.. Instance store NVMe volumes provide temporary, ephemeral block storage directly attached to the EC2 instance, offering extremely low latency and high throughput for temporary processing workspaces. Since the workload requires a temporary workspace where data does not need to persist beyond the instance lifecycle, instance store is the optimal choice because it avoids the cost and overhead of durable storage while delivering the highest performance for scratch data.

Answer

Use io2 EBS volumes because they provide the highest durable block storage performance.

Answer

Use Amazon EFS for the workspace so the temporary files survive instance replacement.

Answer

Use S3 as the working directory and read and write the intermediate files directly there.

Question 10

Based on the exhibit, which design change is the best way to reduce the observed read latency for this DynamoDB-backed service?

Accepted Answer

Add a DynamoDB Accelerator (DAX) cluster in front of the table and send repeated read traffic through it.. Adding a DynamoDB Accelerator (DAX) cluster in front of the table reduces read latency by providing an in-memory cache that serves repeated read requests with microsecond response times, bypassing the need to read from the underlying DynamoDB table's SSD storage. This directly addresses the observed latency issue for frequently accessed data, as DAX is optimized for read-heavy workloads and supports eventual and strong consistency reads.

Answer

Increase the on-demand table limits so DynamoDB can automatically absorb more traffic.

Answer

Create a global secondary index on tenantId to distribute the load across more partitions.

Answer

Move the dashboard data into S3 and use Lambda functions to read it on demand.

Question 11

Based on the exhibit, which change will most improve the CloudFront cache hit ratio for the static assets while still serving the same files to all users?

Accepted Answer

Create a custom cache policy that includes only the v query string and excludes cookies.. The CloudFront cache hit ratio for static assets is reduced when query strings and cookies are forwarded to the origin, because each unique combination creates a separate cache entry. By creating a custom cache policy that includes only the 'v' query string (used for versioning) and excludes cookies, CloudFront can cache a single object for all users regardless of other query parameters or cookie values, maximizing cache hits while still serving the same file.

Answer

Enable Origin Shield and keep the current cache behavior unchanged.

Answer

Move the static assets to individual presigned URLs for each viewer.

Answer

Increase the CloudFront default TTL to 24 hours while continuing to forward all cookies and query strings.

Question 12

A media platform serves global users through Amazon CloudFront and an S3 origin. Match each requirement on the left to the CloudFront configuration or behavior on the right.

Question 13

A retail analytics app uses Amazon RDS for PostgreSQL. Read traffic is growing, and the database CPU spikes mainly due to SELECT-heavy workloads. Writes are less frequent, and the app can tolerate eventually consistent reads for the reports. What is the most appropriate AWS-native way to improve read performance with minimal application changes?

Accepted Answer

Create an RDS read replica and point the reporting queries to the replica endpoint.. Creating an RDS read replica is the most appropriate AWS-native solution because it offloads SELECT-heavy read traffic from the primary database instance to a separate read-only replica, reducing CPU spikes on the primary. The application can tolerate eventually consistent reads for reports, which aligns with the natural replication lag of RDS read replicas (typically sub-second). This requires minimal application changes—only updating the reporting queries to point to the replica endpoint—and leverages PostgreSQL's built-in streaming replication.

Answer

Switch the cluster to DynamoDB without redesigning the data model.

Answer

Enable S3 event notifications to trigger a Lambda function after each write to the database.

Answer

Replace the RDS instance class with a smaller size to reduce cost and improve performance.

Question 14

Based on the exhibit, what is the best change to improve read performance without increasing write latency on the primary database?

Accepted Answer

Create an RDS read replica and direct the reporting queries to the replica endpoint.. Creating an RDS read replica offloads read-heavy reporting queries from the primary database instance, improving read performance without adding any write latency to the primary. The replica operates asynchronously, so writes on the primary are not blocked or delayed by the replica's lag. This is the standard AWS solution for scaling read traffic on RDS.

Answer

Convert the DB instance to Multi-AZ so the primary can serve more reads.

Answer

Increase the primary instance class to a larger size and keep all traffic on one writer.

Answer

Migrate the reporting workload to DynamoDB to gain faster reads.

Question 15

A company serves mostly static images and JavaScript files from an origin in one AWS Region. They want to reduce origin load and improve global performance. Which change most directly increases cache-hit ratio for static assets while avoiding stale content?

Accepted Answer

Use versioned file names (e.g., app.abc123.js) and configure a long TTL with appropriate revalidation behavior.. Option B is correct because using versioned file names (e.g., app.abc123.js) allows you to set a long Cache-Control max-age TTL (e.g., one year) without risking stale content. When the file changes, the versioned name changes, creating a new URL that forces a cache miss and fetches the fresh content. This directly increases the cache-hit ratio for static assets while ensuring clients never serve outdated files.

Answer

Set Cache-Control headers on the origin to always be no-cache so clients revalidate frequently.

Answer

Disable query string forwarding so all URLs without query strings share one cached object even when content differs.

Answer

Forward all headers, including cookies, to maximize personalization in edge cached responses.

SAA-C03 Design High-Performing Architectures Practice Test 4 — 15 Questions

Exhibit

SAA-C03 Design High-Performing Architectures Practice Test 4 — 15 Questions

Exhibit