SAA-C03 Design Resilient Architectures Practice Test 17 — 15 Questions

Question 1

A production Amazon RDS database already has automated backups enabled. At 10:45 UTC, the team discovers that a faulty migration corrupted rows in a table at 10:30 UTC. The business wants the database restored to exactly the state it had at 10:30 UTC with minimal risk. Which two actions should the team take? Select two.

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

Accepted Answer

Restore the database to a new instance using point-in-time restore for 10:30 UTC.. Amazon RDS Point-in-Time Restore (PITR) allows you to restore a DB instance to any second within the backup retention period, including 10:30 UTC. This uses automated backups and transaction logs to reconstruct the exact database state at that specific time, providing a precise recovery point with minimal data loss.

Answer

Restore the most recent manual snapshot because it will include the 10:30 UTC state.

Answer

Overwrite the existing database instance in place so the application keeps the same storage volume.

Answer

Wait for automated backups to complete again, then replay the migration to restore the missing rows.

Question 2

A worker service consumes messages from an Amazon SQS queue. Some messages are malformed and always fail validation. The worker retries, but it keeps reprocessing the same bad messages and consumes processing capacity that should be used for valid work. What is the best solution to prevent “poison messages” from blocking progress?

Accepted Answer

Configure a Dead-Letter Queue (DLQ) and set a redrive policy so messages move to the DLQ after a maximum number of receives.. A Dead-Letter Queue (DLQ) with a redrive policy is the standard AWS mechanism for handling poison messages. By setting a maximum receive count (e.g., 5), the SQS queue automatically moves messages that fail processing repeatedly to the DLQ, isolating them from the main queue. This prevents the worker from wasting capacity on invalid messages and allows the main queue to continue processing valid work without interruption.

Answer

Increase the visibility timeout so the worker gets fewer retries per hour.

Answer

Disable SQS retries by deleting messages immediately on any processing error.

Answer

Create a second worker that polls the queue less frequently until the malformed message is processed successfully.

Question 3

Based on the exhibit, which Route 53 configuration should be used so traffic automatically returns to the secondary Region only when the primary Region becomes unhealthy?

Accepted Answer

Use failover routing with a primary alias record, a secondary alias record, and a Route 53 health check on the primary target.. Failover routing in Amazon Route 53 is designed for active-passive configurations. By creating a primary alias record pointing to the ALB in the primary Region and a secondary alias record pointing to the ALB in the secondary Region, and attaching a Route 53 health check to the primary target, traffic automatically fails over to the secondary Region only when the health check detects the primary as unhealthy. This meets the requirement of returning traffic to the secondary Region only upon primary failure.

Answer

Use latency-based routing with both ALB records enabled.

Answer

Use geolocation routing so users are always sent to the closest Region.

Answer

Use a CNAME record that points to both ALBs so DNS can round-robin between Regions.

Question 4

Based on the exhibit, the application should continue serving requests if one Availability Zone fails. Which change best improves resilience with the least operational complexity?

Accepted Answer

Add at least one subnet from a second Availability Zone to both the ALB and the Auto Scaling group.. Adding subnets from a second Availability Zone to both the ALB and the Auto Scaling group distributes the application across multiple AZs. This ensures that if one AZ fails, the ALB can route traffic to healthy targets in the remaining AZ, and the Auto Scaling group can maintain capacity by launching instances in the surviving AZ. This approach directly addresses the requirement to continue serving requests during an AZ failure with minimal operational complexity.

Answer

Increase the desired capacity in AZ-a so more instances can absorb the failure of that same Availability Zone.

Answer

Disable health checks so the ALB stops removing targets during brief infrastructure issues.

Answer

Move the application to a single larger instance type so the fleet has fewer moving parts.

Question 5

A trading dashboard stores uploaded documents in S3. The business requires a copy in another AWS Region for disaster recovery. What should be configured?

Accepted Answer

S3 Cross-Region Replication with versioning enabled. S3 Cross-Region Replication (CRR) with versioning enabled automatically replicates objects to a destination bucket in a different AWS Region, providing a durable, low-latency disaster recovery copy. Versioning must be enabled on both source and destination buckets to track object changes and ensure consistency during replication. This meets the requirement for a cross-region copy without manual intervention.

Answer

An EBS snapshot schedule

Answer

S3 lifecycle transition to Glacier Flexible Retrieval

Answer

A CloudFront distribution

Question 6

A claims workflow uses an RDS MySQL database and must remain available during an Availability Zone failure with minimal application changes. What should the architect enable?

Accepted Answer

Multi-AZ deployment for the RDS DB instance. Multi-AZ deployment for RDS MySQL automatically provisions and maintains a synchronous standby replica in a different Availability Zone. In the event of an AZ failure, Amazon RDS automatically fails over to the standby, providing high availability with minimal application changes (the application simply reconnects to the same endpoint). This meets the requirement for availability during an AZ outage without requiring code modifications.

Answer

S3 Cross-Region Replication

Answer

EBS snapshots every hour

Answer

Read replicas only

Question 7

A trading dashboard uses Aurora MySQL. The company wants fast cross-Region disaster recovery with low RPO. Which architecture should be considered?

Accepted Answer

Aurora Global Database. Aurora Global Database is designed for cross-Region disaster recovery with a typical RPO of 1 second and RTO of less than 1 minute, using storage-based replication that does not impact database performance. This meets the low RPO requirement for a trading dashboard, where data loss must be minimized.

Answer

A single-AZ Aurora cluster

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Manual snapshots copied monthly

Answer

An ElastiCache Redis replica

Question 8

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 design must avoid adding custom operational scripts.

Accepted Answer

Amazon SQS queue. Amazon SQS is the correct choice because it acts as a durable, fully managed message buffer that decouples the web tier from the fulfilment workers. When bursts of orders arrive, SQS queues the messages and allows workers to poll at their own pace, absorbing spikes without data loss. The built-in retry logic (visibility timeout and dead-letter queue) ensures failed processing attempts are automatically retried, and no custom operational scripts are needed.

Answer

AWS WAF

Answer

Amazon CloudFront

Answer

Amazon Route 53 weighted routing

Question 9

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 design must avoid adding custom operational scripts.

Accepted Answer

S3 Cross-Region Replication with versioning enabled. S3 Cross-Region Replication (CRR) automatically replicates objects to a destination bucket in a different AWS Region, meeting the disaster recovery requirement without custom scripts. Versioning must be enabled on both source and destination buckets for CRR to function, as it tracks object versions and ensures consistency during replication.

Answer

An EBS snapshot schedule

Answer

S3 lifecycle transition to Glacier Flexible Retrieval

Answer

A CloudFront distribution

Question 10

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 design must avoid adding custom operational scripts.

Accepted Answer

Amazon EFS with mount targets in multiple Availability Zones. Amazon EFS provides a fully managed, POSIX-compliant NFSv4.1 shared file system that can be mounted concurrently across multiple Linux EC2 instances. By deploying mount targets in multiple Availability Zones, the file system remains accessible even if one AZ fails, satisfying the high-availability requirement without any custom scripts.

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 11

A regional web application for a content publishing system must fail over automatically to a secondary Region if the primary endpoint becomes unhealthy. Which two services or features are required? The design must avoid adding custom operational scripts.

Accepted Answer

Route 53 failover routing with health checks. Route 53 failover routing with health checks is required because it automatically directs traffic away from an unhealthy primary endpoint to a secondary endpoint, enabling cross-region failover without custom scripts. A deployed standby application stack in the secondary Region is necessary to serve traffic when the primary fails, as Route 53 can only route to healthy endpoints that are actually running.

Answer

AWS Organizations service control policies

Answer

S3 Transfer Acceleration

Question 12

A inventory service 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 design must avoid adding custom operational scripts.

Accepted Answer

A Lambda dead-letter queue or failure destination. A Lambda dead-letter queue (DLQ) or failure destination allows you to capture events that have exhausted all retry attempts from an asynchronous invocation. When the Lambda function fails after the maximum retries (default 3), the event is sent to the configured SQS queue or SNS topic for later investigation, without requiring custom scripts or manual polling.

Answer

Lambda reserved concurrency set to zero

Answer

A larger deployment package

Answer

CloudFront error pages

Question 13

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 14

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 15

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