SAA-C03 Design Resilient Architectures Practice Test 14 — 15 Questions

Question 1

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 2

A payments API requires point-in-time recovery and accidental-delete protection for a DynamoDB table. Which two settings should the architect enable? The design must avoid adding custom operational scripts.

Accepted Answer

Deletion protection or tightly controlled delete permissions. Deletion protection (option A) prevents accidental deletion of the DynamoDB table itself, which is critical for the accidental-delete protection requirement. Point-in-time recovery (option B) enables restoring the table to any point within the last 35 days, satisfying the point-in-time recovery requirement. Both features are native DynamoDB capabilities that require no custom scripts.

Answer

Global secondary indexes

Answer

DAX

Question 3

A ticket booking system uses Aurora MySQL. The company wants fast cross-Region disaster recovery with low RPO. Which architecture should be considered? The design must avoid adding custom operational scripts.

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 1 minute, using storage-based replication that does not require custom scripts. It replicates data from a primary Region to up to five secondary Regions with minimal impact on database performance, meeting the low RPO requirement without operational overhead.

Answer

A single-AZ Aurora cluster

Answer

An ElastiCache Redis replica

Answer

Manual snapshots copied monthly

Question 4

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 design must avoid adding custom operational scripts.

Accepted Answer

CloudFront caching with appropriate TTLs. CloudFront caches responses at edge locations based on configured TTLs (Cache-Control or Expires headers). If the S3 origin becomes temporarily unavailable, CloudFront can still serve stale or cached content to users, maintaining availability without any custom scripts or failover logic. This directly addresses the requirement to serve cached pages during short S3 outages.

Answer

AWS Backup Vault Lock

Answer

IAM Access Analyzer

Answer

S3 Select

Question 5

A patient portal 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 guarantee at-least-once delivery, which satisfies the requirement that every event is processed at least once. The design avoids custom operational scripts by leveraging a fully managed service, and the acceptance of duplicate processing is handled by making consumers idempotent. This combination provides a scalable, resilient, and cost-effective event-driven architecture without the need for custom infrastructure management.

Answer

Use an in-memory queue on one EC2 instance

Answer

Use UDP messages sent directly to workers

Answer

Use CloudFront signed URLs

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? The design must avoid adding custom operational scripts.

Accepted Answer

Multi-AZ deployment for the RDS DB instance. Multi-AZ deployment for RDS MySQL provides automatic failover to a standby replica in a different Availability Zone. This ensures high availability during an AZ failure with minimal application changes, as the DNS endpoint remains the same and failover is handled by AWS without custom scripts.

Answer

S3 Cross-Region Replication

Answer

EBS snapshots every hour

Answer

Read replicas only

Question 7

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 design must avoid adding custom operational scripts.

Accepted Answer

Subnets in at least two Availability Zones with health checks enabled. Option B is correct because distributing EC2 instances across at least two Availability Zones (AZs) ensures that the Auto Scaling group can maintain capacity even if one AZ fails. Enabling health checks on the Application Load Balancer (ALB) allows the group to automatically replace unhealthy instances without custom scripts, meeting the fault-tolerance requirement.

Answer

A single EC2 instance with detailed monitoring

Answer

All instances in one larger subnet

Answer

A Network Load Balancer in one subnet

Question 8

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 9

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 design must avoid adding custom operational scripts.

Accepted Answer

Amazon SQS queue. Amazon SQS is the correct choice because it acts as a durable, scalable message buffer that decouples the web tier from the fulfilment workers. When order bursts arrive, messages are stored reliably in the queue, and workers can poll at their own pace, retrying failed messages automatically without any custom scripts. This pattern absorbs spikes and ensures no requests are lost, meeting the requirement for a fully managed, serverless integration.

Answer

AWS WAF

Answer

Amazon Route 53 weighted routing

Answer

Amazon CloudFront

Question 10

A payments API uses Amazon SQS. Poison messages are repeatedly failing and blocking useful retries. What should the architect configure? The design must avoid adding custom operational scripts.

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 retries and consuming processing resources, without requiring custom operational scripts.

Answer

A FIFO queue without a redrive policy

Answer

A larger message retention period only

Answer

Short polling instead of long polling

Question 11

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 design must avoid adding custom operational scripts.

Accepted Answer

S3 Cross-Region Replication with versioning enabled. S3 Cross-Region Replication (CRR) automatically replicates objects from a source bucket in one AWS Region to a destination bucket in another Region, providing a disaster recovery copy without custom scripts. Enabling versioning on both buckets is a prerequisite for CRR, ensuring that all object versions are replicated and that the destination bucket can maintain a complete history of changes.

Answer

S3 lifecycle transition to Glacier Flexible Retrieval

Answer

An EBS snapshot schedule

Answer

A CloudFront distribution

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 patient portal 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, scalable, and shared file system that can be mounted concurrently on 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, meeting the high availability requirement without custom scripts.

Answer

Instance store volumes

Answer

An EBS volume attached to all instances

Answer

S3 mounted as a POSIX file system without a file gateway

Question 14

A claims workflow requires point-in-time recovery and accidental-delete protection for a DynamoDB table. Which two settings should the architect enable? The design must avoid adding custom operational scripts.

Accepted Answer

Point-in-time recovery. Point-in-time recovery (PITR) for DynamoDB enables continuous backups with 35-day granularity, allowing restoration to any second within that window. This directly satisfies the point-in-time recovery requirement without custom scripts, as it is a native AWS feature.

Answer

DAX

Answer

Global secondary indexes

Question 15

A trading dashboard uses Aurora MySQL. The company wants fast cross-Region disaster recovery with low RPO. Which architecture should be considered? The design must avoid adding custom operational scripts.

Accepted Answer

Aurora Global Database. Aurora Global Database is the correct choice because it provides a fully managed cross-Region disaster recovery solution with a typical RPO of 1 second or less, using storage-based replication that does not require custom scripts. This meets the low RPO requirement while avoiding operational overhead, as replication is handled automatically by the Aurora storage layer.

Answer

A single-AZ Aurora cluster

Answer

Manual snapshots copied monthly

Answer

An ElastiCache Redis replica