SAA-C03 Design Resilient Architectures Practice Test 24 — 15 Questions

Question 1

A company runs a critical two-tier web application on AWS. The web tier consists of Amazon EC2 instances behind an Application Load Balancer (ALB) in a single Availability Zone. The database tier is an Amazon RDS for MySQL DB instance in the same Availability Zone. A recent power outage in that Availability Zone caused a full application outage. The company wants to redesign the architecture to survive an Availability Zone failure with minimal operational overhead. Which solution meets these requirements?

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

Accepted Answer

Deploy the web tier across two Availability Zones with an ALB, and convert the database to an RDS Multi-AZ DB instance.. The correct design distributes the stateless web tier across multiple Availability Zones and uses an RDS Multi-AZ DB instance for automatic database failover. This eliminates single points of failure at both tiers and requires little ongoing operational effort. Other options either leave the web tier in one AZ or rely on manual recovery for the database, failing the resilience and minimal-overhead goals.

Answer

Use an Application Load Balancer with cross-zone load balancing enabled and enable Multi-AZ on the RDS instance.

Answer

Enable RDS automated backups with a 30-day retention period and create a read replica in a second Availability Zone.

Answer

Place the EC2 instances in an Auto Scaling group spanning two Availability Zones, and take nightly snapshots of the RDS instance to restore in the second AZ.

Question 2

A healthcare company runs a patient portal on Amazon EC2 instances behind an Application Load Balancer across two Availability Zones. A new compliance rule requires that if an entire Availability Zone fails, the portal must remain available with no manual intervention. The EC2 instances are stateless and store no session data. Which design change should the architect implement to meet this requirement?

Accepted Answer

Enable an Auto Scaling group that spans both Availability Zones and configure the load balancer health checks to deregister unhealthy instances.. High availability across Availability Zones requires compute capacity that can be automatically replaced when an AZ fails. An Auto Scaling group spanning multiple AZs, combined with load balancer health checks, ensures that unhealthy instances are removed and new instances are launched in a surviving AZ without human action.

Answer

Convert the EC2 instances to a single larger instance type and enable detailed monitoring in Amazon CloudWatch.

Answer

Configure the Application Load Balancer to use cross-zone load balancing and attach an Elastic IP address to each EC2 instance.

Answer

Place the EC2 instances in a single Availability Zone and create an Amazon EBS snapshot schedule every hour.

Question 3

A logistics company stores shipment events in an Amazon S3 bucket. An analytics team must be able to recover any object version that is accidentally overwritten or deleted for at least 90 days, and objects must be protected from permanent deletion by any user, including the root user, during that window. Which combination of S3 features meets these requirements with the LEAST operational overhead?

Accepted Answer

Enable S3 Versioning and apply an S3 Object Lock retention period of 90 days in compliance mode on the bucket.. S3 Object Lock requires versioning and enforces a retention period during which object versions cannot be deleted or overwritten by anyone, including the root user. Compliance mode cannot be shortened or bypassed, so it uniquely satisfies the requirement to prevent permanent deletion for at least 90 days while still allowing recovery of prior versions.

Answer

Enable S3 Versioning and configure S3 Cross-Region Replication to a second bucket in another Region with a 90-day lifecycle expiration.

Answer

Enable S3 Versioning and configure an S3 Lifecycle rule to transition noncurrent versions to S3 Glacier Deep Archive after 90 days.

Answer

Enable S3 Versioning and add a bucket policy that denies s3:DeleteObject for all principals for 90 days.

Question 4

A media company stores video files in an Amazon S3 bucket in the us-east-1 Region. The company wants to ensure that the files are automatically replicated to us-west-2 for disaster recovery, and that replication occurs within 15 minutes of upload. Which solution meets these requirements with the LEAST operational overhead?

Accepted Answer

Enable S3 Cross-Region Replication (CRR) on the bucket with a replication rule that applies to all objects.. S3 Cross-Region Replication is the managed solution for automatically replicating objects to a bucket in another Region. It is asynchronous but typically completes within minutes, satisfying the 15-minute requirement. It requires versioning and an IAM role, but after setup it runs without ongoing intervention. This provides the lowest operational overhead compared to custom code or scheduled data transfer tasks.

Answer

Configure an AWS Lambda function triggered by S3 event notifications to copy each object to the destination bucket.

Answer

Use AWS DataSync to schedule a recurring task that synchronizes the source bucket to the destination bucket every 15 minutes.

Answer

Enable S3 Same-Region Replication (SRR) to a bucket in us-east-1, then use S3 Batch Operations to copy objects to us-west-2 nightly.

Question 5

A startup runs a stateless web application on a single Amazon EC2 instance in one Availability Zone. The application has become popular, and the startup wants to ensure that the application can survive the failure of an Availability Zone and can handle increased traffic. Which architecture change should the startup make FIRST?

Accepted Answer

Move the application to an Auto Scaling group that spans multiple Availability Zones, and place an Application Load Balancer in front of it.. Moving to an Auto Scaling group across multiple Availability Zones with an Application Load Balancer provides both high availability and elasticity. The load balancer health checks ensure traffic goes only to healthy instances, and the Auto Scaling group replaces failed instances automatically. This architecture eliminates single points of failure and allows the application to scale with demand, which is the fundamental first step for resilience.

Answer

Resize the existing EC2 instance to a larger instance type to handle increased traffic and improve availability.

Answer

Create an Amazon Machine Image (AMI) of the instance and store it in Amazon S3 for quick recovery after a failure.

Answer

Enable detailed monitoring on the EC2 instance and create Amazon CloudWatch alarms to notify the team of failures.

Question 6

A company runs a stateful web application on a fleet of Amazon EC2 instances in an Auto Scaling group. The application stores session state locally on each instance. During an Availability Zone failure, the Auto Scaling group replaces the unhealthy instances in a different AZ, but users lose their sessions and must log in again. The company wants to make the application resilient to AZ failures without requiring users to re-authenticate. Which solution should a solutions architect recommend?

Accepted Answer

Store session state in an Amazon ElastiCache for Redis cluster with Multi-AZ enabled, and configure the application to use it.. Externalizing session state to a Multi-AZ ElastiCache for Redis cluster removes the dependency on local instance storage. When an instance is replaced after an AZ failure, the new instance can retrieve the session from Redis, so users stay logged in. This decouples state from compute and provides automatic failover, meeting the resilience requirement.

Answer

Use Amazon S3 to store session data and configure the application to read and write session files directly to an S3 bucket.

Answer

Configure the Auto Scaling group to launch instances in only one Availability Zone and use a larger instance type to handle the load.

Answer

Enable sticky sessions on the Application Load Balancer and increase the Auto Scaling group's desired capacity.

Question 7

A financial services company runs a critical application on Amazon EC2 instances in an Auto Scaling group behind an Application Load Balancer. The application must be able to survive the failure of an entire AWS Region. The company wants a cost-effective solution that minimizes operational overhead. Which approach should the architect recommend?

Accepted Answer

Deploy the application in two Regions with an Auto Scaling group in each, and use Amazon Route 53 failover routing with health checks.. To survive a regional failure, the application must be deployed in at least two Regions with independent compute capacity. Route 53 failover routing with health checks automatically directs traffic to the healthy Region, providing resilience with minimal manual intervention and operational overhead.

Answer

Deploy the application in one Region and take regular Amazon EBS snapshots copied to another Region.

Answer

Deploy the application in one Region and use AWS Global Accelerator to route traffic to the nearest edge location.

Answer

Deploy the application in two Regions and use an Amazon S3 cross-Region replication bucket to store application logs.

Question 8

A financial services company runs a critical application on Amazon EC2 instances in an Auto Scaling group. The application writes to an Amazon RDS for MySQL database. The company needs a recovery point objective (RPO) of 1 second and a recovery time objective (RTO) of 1 minute for the database in the event of a Regional disaster. Which solution meets these requirements?

Accepted Answer

Use an Amazon Aurora global database with a secondary Region, and perform a managed planned failover or unplanned failover to the secondary Region.. Amazon Aurora global database is designed for cross-Region disaster recovery with low latency replication and fast failover. Replication typically completes in under one second, satisfying the RPO. A managed failover promotes the secondary Region to primary in under a minute, satisfying the RTO. This is the appropriate choice for a MySQL-compatible workload with stringent recovery requirements.

Answer

Configure an RDS for MySQL read replica in a second Region and promote it during a disaster.

Answer

Enable automated backups on the RDS for MySQL instance and copy the backups to a second Region using a cross-Region snapshot copy.

Answer

Use AWS Database Migration Service (DMS) to continuously replicate data from the primary RDS instance to a second Region, and switch the application to the replica during a disaster.

Question 9

A company runs a stateless API on Amazon EC2 instances in a single Availability Zone behind an Application Load Balancer. The ALB currently has a listener on port 80 only. The company wants the API to remain available if the single Availability Zone fails. What should the solutions architect do to meet this requirement with the LEAST operational overhead?

Accepted Answer

Create an Amazon Machine Image (AMI) of the instances and configure an Auto Scaling group across at least two Availability Zones, registering the instances with the existing ALB target group.. Running the stateless API in an Auto Scaling group that spans at least two Availability Zones lets the group replace instances in a surviving zone when one zone becomes unavailable. The existing ALB and target group can be reused, so the change adds zone redundancy with the least operational overhead.

Answer

Enable cross-zone load balancing on the ALB and increase the desired capacity of the existing instances in the single Availability Zone.

Answer

Create a second ALB in another Availability Zone and use Amazon Route 53 failover routing with health checks to switch traffic when the primary zone fails.

Answer

Move the API to an Amazon S3 static website endpoint and serve the traffic through Amazon CloudFront with origin failover.

Question 10

A company stores critical documents in an Amazon S3 bucket in the us-east-1 Region. The documents must survive an unlikely loss of the entire us-east-1 Region. The company wants a recovery point objective (RPO) of 15 minutes and a recovery time objective (RTO) of 1 hour. What should the solutions architect recommend?

Accepted Answer

Enable S3 Cross-Region Replication (CRR) from the us-east-1 bucket to a bucket in us-west-2 and enable S3 Versioning on both buckets.. S3 Cross-Region Replication copies objects to a bucket in a different Region, and versioning is a prerequisite. Replication is asynchronous but typically completes well within a 15-minute RPO, and the destination bucket can serve as the recovery source within the 1-hour RTO.

Answer

Enable S3 server access logging and store the logs in a separate bucket in us-east-1.

Answer

Configure an S3 Lifecycle rule to transition objects to S3 Glacier Deep Archive after 30 days.

Answer

Enable S3 Transfer Acceleration on the us-east-1 bucket to speed up uploads from global clients.

Question 11

A healthcare data platform stores patient documents in an Amazon S3 bucket in us-east-1. Regulations require that the data remain readable with low latency even if the entire us-east-1 Region becomes unavailable, and that writes continue in a secondary Region. The team wants object-level replication with minimal operational overhead and must preserve version history. Which solution BEST meets these requirements?

Accepted Answer

Enable S3 Cross-Region Replication (CRR) with versioning enabled on both buckets, and configure the application to read from the replica bucket during a regional failure.. Cross-Region Replication copies objects to a bucket in another Region and requires versioning on both buckets, which preserves version history. The replica bucket remains accessible if the primary Region fails, and writes can be directed there, meeting both the availability and data-durability goals with minimal operational effort.

Answer

Use S3 Transfer Acceleration on the existing bucket and rely on edge locations to serve reads during the outage.

Answer

Enable S3 Same-Region Replication to a second bucket in us-east-1 and serve reads from that bucket during a regional failure.

Answer

Configure an S3 Lifecycle policy to transition objects to S3 Glacier Deep Archive in a second Region.

Question 12

A company is building a serverless application that processes messages from an Amazon SQS queue using AWS Lambda. The application must not lose messages and must handle occasional downstream failures gracefully. The Lambda function sometimes fails due to a transient error in a downstream service. The company wants to ensure that failed messages are retried and eventually processed, but also wants to avoid infinite retries that could block the queue. What should the company do?

Accepted Answer

Configure a dead-letter queue (DLQ) on the source SQS queue and set the maximumReceiveCount to a reasonable value.. Using a dead-letter queue on the source SQS queue with a maximumReceiveCount ensures that messages are retried a limited number of times and then moved to a DLQ for separate handling. This prevents poison messages from blocking the queue and allows for later analysis or reprocessing, meeting the requirement to avoid infinite retries while not losing messages.

Answer

Increase the Lambda function's timeout and memory allocation to reduce the chance of transient errors.

Answer

Set the SQS queue's visibility timeout to a very high value so that messages are not retried until the downstream service recovers.

Answer

Configure the Lambda function to write failed messages to an Amazon S3 bucket and delete them from the queue.

Question 13

A company runs a stateful workload on Amazon EC2 instances in an Auto Scaling group. The workload writes session data to the instance store and to an Amazon EBS volume attached at launch. The company wants the workload to survive an Availability Zone failure without losing session data. What should the solutions architect do?

Accepted Answer

Move session data to Amazon ElastiCache for Redis with Multi-AZ enabled, and configure the Auto Scaling group to span multiple Availability Zones.. Session data must be moved off instance-bound storage to a multi-AZ data store. ElastiCache for Redis with Multi-AZ automatically fails over to a replica in another zone, and an Auto Scaling group spanning multiple zones can launch replacement instances that reconnect to the session store.

Answer

Create an Amazon EBS snapshot schedule for the attached volumes and restore the snapshots in another Availability Zone after a failure.

Answer

Attach an additional EBS volume to each instance and configure RAID 0 across the two volumes for higher durability.

Answer

Enable termination protection on the instances and configure the Auto Scaling group to use a single Availability Zone.

Question 14

A company runs a critical application on Amazon EC2 instances in a single Availability Zone. The application writes data to an Amazon RDS for MySQL DB instance that is not Multi-AZ. The company wants to improve the resilience of the database tier so that it can survive an Availability Zone failure with minimal downtime and no data loss. The application uses the database endpoint from the RDS console. Which solution meets these requirements?

Accepted Answer

Convert the DB instance to a Multi-AZ deployment and update the application to use the same endpoint.. Multi-AZ deployments for Amazon RDS provide a synchronous standby replica in a different Availability Zone. In the event of an AZ failure, RDS automatically fails over to the standby, and the application continues to use the same endpoint. Because replication is synchronous, there is no data loss. This meets the requirements of minimal downtime and no data loss without application changes.

Answer

Create a read replica in another Availability Zone and manually promote it if the primary fails.

Answer

Enable automated backups with a retention period of 35 days and copy the backups to another Region.

Answer

Migrate the database to Amazon DynamoDB with global tables and update the application to use the DynamoDB endpoint.

Question 15

A company runs a web application on Amazon EC2 instances behind an Application Load Balancer. The application must be highly available and able to withstand the failure of an entire AWS Region. The company wants to minimize operational overhead and ensure that failover is automatic. Which solution should a solutions architect recommend?

Accepted Answer

Deploy the application in two AWS Regions. Use Amazon Route 53 with a failover routing policy and health checks to route traffic to the secondary Region if the primary becomes unhealthy.. To withstand a Region failure with automatic failover, the application must be deployed in at least two Regions. Route 53 failover routing with health checks automatically redirects traffic to the secondary Region when the primary is unhealthy. This minimizes operational overhead because the failover is managed by Route 53 and does not require manual intervention.

Answer

Deploy the application in two AWS Regions. Use Amazon Route 53 with a weighted routing policy and equal weights for both Regions.

Answer

Deploy the application in two Availability Zones within a single Region. Use an Application Load Balancer to distribute traffic across both AZs.

Answer

Deploy the application in a single Region using AWS Global Accelerator to route traffic to the nearest edge location.