SAA-C03 Design Resilient Architectures Practice Test 18 — 15 Questions

Question 1

A content publishing system exposes a static website from S3 and CloudFront. Users should still receive cached pages if the S3 origin has a short outage. Which feature helps most? The design must avoid adding custom operational scripts.

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

Accepted Answer

CloudFront caching with appropriate TTLs. CloudFront caches responses from the S3 origin based on configured TTLs (Cache-Control or Expires headers). If the S3 origin experiences a short outage, CloudFront can still serve cached content to users as long as the TTL has not expired, ensuring availability without custom scripts. This is the most direct and resilient feature for this use case.

Answer

IAM Access Analyzer

Answer

AWS Backup Vault Lock

Answer

S3 Select

Question 2

A warehouse integration service must process every event at least once, but duplicate processing is acceptable if the consumer handles idempotency. Which eventing approach is most suitable? The design must avoid adding custom operational scripts.

Accepted Answer

Use Amazon SQS standard queue and design consumers to be idempotent. Amazon SQS standard queues provide at-least-once delivery, ensuring every event is processed at least once, with the possibility of duplicates. Designing consumers to be idempotent handles duplicates without requiring custom scripts, aligning with the requirement to avoid operational overhead. This approach is serverless, scalable, and fits the warehouse integration use case.

Answer

Use CloudFront signed URLs

Answer

Use UDP messages sent directly to workers

Answer

Use an in-memory queue on one EC2 instance

Question 3

A ticket booking system runs on EC2 instances behind an Application Load Balancer. The design must tolerate the failure of one Availability Zone. What should the Auto Scaling group configuration include? The architecture review board prefers a managed AWS-native control.

Accepted Answer

Subnets in at least two Availability Zones with health checks enabled. An Auto Scaling group configured with subnets in at least two Availability Zones ensures that if one AZ fails, the remaining AZ(s) can continue to serve traffic. Health checks on the EC2 instances allow the Auto Scaling group to detect and replace unhealthy instances, maintaining the desired capacity across the surviving AZs. This aligns with the requirement for a managed AWS-native control to tolerate an AZ failure.

Answer

All instances in one larger subnet

Answer

A Network Load Balancer in one subnet

Answer

A single EC2 instance with detailed monitoring

Question 4

A patient portal receives bursts of orders that sometimes overwhelm a downstream fulfilment service. The architecture must absorb spikes and retry processing without losing requests. Which service should be placed between the web tier and fulfilment workers? The architecture review board prefers a managed AWS-native control.

Accepted Answer

Amazon SQS queue. Amazon SQS is the correct choice because it acts as a decoupling buffer between the web tier and the fulfilment workers. It can absorb sudden bursts of orders by storing messages durably, and workers can poll the queue at their own pace, retrying failed processing without losing any requests. This aligns with the requirement for a managed AWS-native service that handles spikes and retries.

Answer

AWS WAF

Answer

Amazon CloudFront

Answer

Amazon Route 53 weighted routing

Question 5

A claims workflow uses Amazon SQS. Poison messages are repeatedly failing and blocking useful retries. What should the architect configure? The architecture review board prefers a managed AWS-native control.

Accepted Answer

A dead-letter queue with an appropriate maxReceiveCount. A dead-letter queue (DLQ) with an appropriate maxReceiveCount allows messages that repeatedly fail processing to be moved out of the source queue after a specified number of receive attempts. This prevents poison messages from blocking useful retries and is a fully managed AWS-native pattern. The architecture review board's preference for a managed solution is satisfied because SQS DLQs are a built-in feature requiring no custom code.

Answer

A FIFO queue without a redrive policy

Answer

Short polling instead of long polling

Answer

A larger message retention period only

Question 6

A trading dashboard stores uploaded documents in S3. The business requires a copy in another AWS Region for disaster recovery. What should be configured? The architecture review board prefers a managed AWS-native control.

Accepted Answer

S3 Cross-Region Replication with versioning enabled. S3 Cross-Region Replication (CRR) is the correct AWS-native managed solution for automatically replicating objects from a source S3 bucket in one region to a destination bucket in another region, meeting the disaster recovery requirement. Versioning must be enabled on both source and destination buckets for CRR to function, as replication relies on version IDs to track and copy objects. This provides asynchronous, automatic replication without custom scripting or third-party tools.

Answer

An EBS snapshot schedule

Answer

S3 lifecycle transition to Glacier Flexible Retrieval

Answer

A CloudFront distribution

Question 7

A content publishing system uses Lambda functions that call an unreliable third-party API. Failed events must be retained for later investigation after retries are exhausted. What should be configured? The architecture review board prefers a managed AWS-native control.

Accepted Answer

A Lambda dead-letter queue or failure destination. Lambda dead-letter queues (DLQs) or failure destinations are the managed AWS-native way to capture events that have exhausted all retry attempts from an asynchronous invocation. When the Lambda function fails after the configured number of retries (default 3), the event is automatically sent to an SQS queue or SNS topic (DLQ) or to a specified destination (e.g., SQS, SNS, EventBridge) for later investigation and reprocessing.

Answer

Lambda reserved concurrency set to zero

Answer

A larger deployment package

Answer

CloudFront error pages

Question 8

A warehouse integration service must use shared file storage across Linux EC2 instances in multiple Availability Zones. The storage must remain available during an AZ failure. Which service should be used? The architecture review board prefers a managed AWS-native control.

Accepted Answer

Amazon EFS with mount targets in multiple Availability Zones. Amazon EFS provides a fully managed, NFS-based shared file system that can be mounted concurrently by multiple Linux EC2 instances across different Availability Zones. By creating mount targets in each AZ, the file system remains accessible even if one AZ fails, as traffic is automatically routed to the surviving mount targets. This meets the requirement for shared, resilient storage with a managed AWS-native control plane.

Answer

S3 mounted as a POSIX file system without a file gateway

Answer

Instance store volumes

Answer

An EBS volume attached to all instances

Question 9

A payments API requires point-in-time recovery and accidental-delete protection for a DynamoDB table. Which two settings should the architect enable? The architecture review board prefers a managed AWS-native control.

Accepted Answer

Deletion protection or tightly controlled delete permissions. Point-in-time recovery (PITR) enables continuous backups of the DynamoDB table, allowing restoration to any point within the last 35 days, which satisfies the requirement for point-in-time recovery. Deletion protection prevents accidental deletion of the table by blocking drop-table operations, meeting the accidental-delete protection requirement. Both are managed AWS-native controls that require no custom scripting or external tooling.

Answer

Global secondary indexes

Answer

DAX

Question 10

A ticket booking system uses Aurora MySQL. The company wants fast cross-Region disaster recovery with low RPO. Which architecture should be considered? The architecture review board prefers a managed AWS-native control.

Accepted Answer

Aurora Global Database. Aurora Global Database is the correct choice because it provides a managed, cross-Region disaster recovery solution with a Recovery Point Objective (RPO) of typically less than 1 second, using storage-based replication that does not impact database performance. This meets the requirement for fast failover and low data loss, while being fully AWS-native and controlled by the architecture review board.

Answer

A single-AZ Aurora cluster

Answer

An ElastiCache Redis replica

Answer

Manual snapshots copied monthly

Question 11

A inventory service exposes a static website from S3 and CloudFront. Users should still receive cached pages if the S3 origin has a short outage. Which feature helps most? The architecture review board prefers a managed AWS-native control.

Accepted Answer

CloudFront caching with appropriate TTLs. CloudFront caching with appropriate TTLs allows cached responses to be served to users even when the S3 origin is temporarily unavailable. By setting a minimum TTL (e.g., 0 seconds for fresh content, but a higher default or maximum TTL for stale content), CloudFront can continue delivering previously cached pages from edge locations during an S3 outage, ensuring high availability and resilience. This is a managed AWS-native feature that aligns with the architecture review board's preference.

Answer

AWS Backup Vault Lock

Answer

IAM Access Analyzer

Answer

S3 Select

Question 12

A trading dashboard runs on EC2 instances behind an Application Load Balancer. The design must tolerate the failure of one Availability Zone. What should the Auto Scaling group configuration include? The architecture review board prefers a managed AWS-native control.

Accepted Answer

Subnets in at least two Availability Zones with health checks enabled. Distributing EC2 instances across at least two Availability Zones (AZs) ensures that the application remains available if one AZ fails. The Auto Scaling group must include subnets in multiple AZs and use health checks (e.g., ELB health checks) to automatically replace unhealthy instances. This configuration meets the requirement for fault tolerance and aligns with AWS-managed best practices for high availability.

Answer

A single EC2 instance with detailed monitoring

Answer

All instances in one larger subnet

Answer

A Network Load Balancer in one subnet

Question 13

A warehouse integration service receives bursts of orders that sometimes overwhelm a downstream fulfilment service. The architecture must absorb spikes and retry processing without losing requests. Which service should be placed between the web tier and fulfilment workers? The architecture review board prefers a managed AWS-native control.

Accepted Answer

Amazon SQS queue. Amazon SQS is the correct choice because it acts as a fully managed message queue that decouples the web tier from the fulfilment workers, buffering incoming order bursts. It provides at-least-once delivery and allows workers to poll messages at their own pace, ensuring no requests are lost even during spikes. SQS also supports retries via a dead-letter queue (DLQ) for messages that fail processing, meeting the requirement for resilient, managed AWS-native control.

Answer

AWS WAF

Answer

Amazon Route 53 weighted routing

Answer

Amazon CloudFront

Question 14

A payments API uses Amazon SQS. Poison messages are repeatedly failing and blocking useful retries. What should the architect configure? The architecture review board prefers a managed AWS-native control.

Accepted Answer

A dead-letter queue with an appropriate maxReceiveCount. A dead-letter queue (DLQ) with an appropriate maxReceiveCount is the correct AWS-native solution for handling poison messages. When a message is repeatedly received from an SQS queue but fails processing, it is considered a poison message. By configuring a DLQ and setting a maxReceiveCount (e.g., 3 or 5), the message is automatically moved to the DLQ after exceeding that threshold, preventing it from blocking further retries and allowing the main queue to process valid messages.

Answer

A FIFO queue without a redrive policy

Answer

A larger message retention period only

Answer

Short polling instead of long polling

Question 15

A ticket booking system stores uploaded documents in S3. The business requires a copy in another AWS Region for disaster recovery. What should be configured? The architecture review board prefers a managed AWS-native control.

Accepted Answer

S3 Cross-Region Replication with versioning enabled. S3 Cross-Region Replication (CRR) is a fully managed AWS-native feature that automatically replicates objects from a source S3 bucket in one AWS Region to a destination bucket in another Region, meeting the disaster recovery requirement for a geographically separate copy. Enabling versioning on both buckets is mandatory for CRR to function, as it tracks object versions and ensures consistency during replication.

Answer

S3 lifecycle transition to Glacier Flexible Retrieval

Answer

An EBS snapshot schedule

Answer

A CloudFront distribution