Design Resilient Architectures

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.

A payments platform requires disaster recovery across Regions. Requirements: RPO of 15 minutes and RTO of about 1 hour. The business cannot afford full duplicate capacity in both Regions all the time, but the team wants automated readiness so failover is mostly operationally guided rather than a slow rebuild. Which DR strategy is the best fit?

Your order-processing system uses EventBridge rules to send events to a Lambda function that updates order status. Over the last week, some events fail with a transient database timeout, and the Lambda retries intermittently but then the events are lost (no alerts after failures). You want at-least-once processing, bounded retries, and a way to inspect unprocessable events for later reprocessing. Which architecture change best meets these requirements?

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.

Based on the exhibit, a web application must stay available if one Availability Zone fails. What is the best change to improve resilience?

A retail API runs on Amazon EC2 instances behind an Application Load Balancer and stores orders in an Amazon RDS for PostgreSQL database. A test that stopped one Availability Zone caused the API to return errors because all application servers were in the same AZ and the database was single-AZ. Which two changes should the architect make to continue serving traffic during a single-AZ failure? Select two.

Match the disaster recovery strategy to the recovery posture it best fits for a Regional outage.

A team uses an S3 bucket to store important customer-generated exports. They need protection against accidental overwrites and also want copies of the data in another AWS Region for disaster recovery. Which S3 configuration best satisfies both requirements?

A customer portal must recover from a regional outage within a few hours. The business wants lower ongoing cost than a fully active second Region and does not want to rebuild everything from scratch during the outage. Which two DR patterns best fit that goal? Select two.

A solutions architect is designing a highly available and resilient architecture for a critical internal application that processes financial transactions. The application runs on Amazon EC2 instances inside an Auto Scaling group. The database layer uses an Amazon Aurora MySQL cluster. The company requires that if an entire AWS Availability Zone (AZ) fails, the application must remain operational with minimal impact and automatically recover without manual intervention. Which combination of architectural decisions will meet these requirements? (Choose four.)

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?

A developer accidentally corrupts part of a production Amazon RDS database, and the issue is discovered 45 minutes later. The team needs to restore the database to the state immediately before the change. Which two actions should be part of the recovery plan? Select two.

Based on the exhibit, the database must fail over automatically if the primary Availability Zone goes down. Which solution should the architect choose?

A global application experiences frequent writes and must survive a full Regional outage with near-zero data loss. The product team also requires that users can continue to write during the incident using the closest Region. Which approach is most aligned with these requirements?

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.

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 team wants the control to be enforceable during normal operations.

Order the steps to create a static website using Amazon S3 and CloudFront.

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?

A company runs its customer-facing web app on EC2 behind an Application Load Balancer. The database is Amazon RDS for PostgreSQL. The requirement is that if a single Availability Zone fails, the database must automatically fail over within the same AWS Region with minimal application changes. Which database setup best meets this requirement?

A company is deploying a stateless web application on Amazon ECS with Fargate. The application must be resilient to individual task failures and Availability Zone failures. Which three steps should the company take to achieve this resilience? (Choose three.)

A media company stores daily financial exports in Amazon S3. The files must be protected against accidental overwrite or deletion, and the business also wants a second copy in another Region for recovery after a regional outage. Which two actions should the architect take? Select two.

A serverless order-ingestion API writes directly to a database. During traffic spikes, the database occasionally throttles, Lambda retries create duplicate order records, and some requests time out. Which two changes best improve buffering and safe retry behavior? Select two.

An engineering team deploys a stateless web API on EC2 using an Auto Scaling group and an Application Load Balancer (ALB). During a recent test, they noticed that when one Availability Zone was unavailable, traffic failed until new instances were manually launched. Which change most directly improves automatic failover for the compute layer within a single Region?

A regional web application for a inventory service must fail over automatically to a secondary Region if the primary endpoint becomes unhealthy. Which two services or features are required? The team wants the control to be enforceable during normal operations.

A payments platform requires disaster recovery across Regions. Requirements: RPO of 15 minutes and RTO of about 1 hour. The business cannot afford full duplicate capacity in both Regions all the time, but the team wants automated readiness so failover is mostly operationally guided rather than a slow rebuild. Which DR strategy is the best fit?

A SaaS application is deployed in us-east-1 and us-west-2 behind separate ALBs. The business wants DNS to send new clients to the primary Region when it is healthy and automatically fail over to the secondary Region when the primary endpoint is unhealthy. Which two Route 53 settings are required? Select two.

A company uses Amazon RDS for a PostgreSQL database powering a customer-facing application. The application’s availability depends on fast database failover with minimal manual intervention. The RDS instance currently runs as a single-AZ deployment in one DB subnet group. Which change most directly meets the goal?

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

A SaaS platform serves an API using two regional deployments: us-east-1 (primary) and us-west-2 (secondary). Each region has its own ALB. The business requires automated DNS-based failover when the primary region becomes unhealthy, and they do not want manual DNS changes during incidents. Which Route 53 configuration is the best match?

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.

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

An events service publishes critical notifications using Amazon SNS. Three independent downstream systems (A, B, and C) subscribe to the topic. Downstream system B sometimes fails to process certain messages (for example, it times out or returns an error while handling the message), and you want: 1) failures in B to be isolated so A and C keep processing unaffected, and 2) messages that B cannot successfully process after retries to be sent to a DLQ for B. Which design best meets these requirements?

A stateless web API runs on EC2 instances behind an Application Load Balancer (ALB). The Auto Scaling group (ASG) currently uses subnets from only one Availability Zone, even though the ALB spans two Availability Zones. During maintenance of that single AZ, the ALB remains up but clients see timeouts because there are no healthy targets. Which change most directly improves resilience against an AZ failure?

A web application runs on an Auto Scaling group (ASG) behind an Application Load Balancer (ALB). The ASG is currently attached to subnets in only two Availability Zones (AZs). During a planned maintenance window, one AZ becomes unavailable for about 25 minutes. Monitoring shows that targets in the remaining AZ go healthy, and the ALB/target group health checks report normal. However, users still experience intermittent connection failures and slower responses during the AZ outage. What change will most directly improve resilience against an AZ loss while keeping the same ALB-based design?

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.

A retail platform needs disaster recovery across AWS Regions. The business requirement is: RTO up to 6 hours, RPO up to 1 hour, and they want the ability to start serving quickly during a Region outage but do not want to run full production capacity continuously. Which DR strategy best fits these requirements?

A caching layer uses Amazon ElastiCache for Redis in front of a stateless web service. The service must continue to read cached responses during maintenance events and should automatically fail over to another node if one AZ becomes impaired. Which design change best satisfies this requirement?

An order-processing worker consumes messages from Amazon SQS. Occasionally, the worker times out after successfully creating a payment record but before deleting the message, which causes duplicate charges during retries. Some messages also fail validation repeatedly because required fields are missing. Which two changes should the team make? Select two.

A company runs a stateful analytics workload on EC2 instances that use EBS volumes. The data must be restorable in another Region after a major outage, with frequent point-in-time recovery. Which approach provides the most suitable replication mechanism for the EBS-backed data?

A web application runs on an Amazon EC2 Auto Scaling group (ASG) behind an Application Load Balancer (ALB). The ALB is configured to use at least two Availability Zones (AZs), but the ASG currently uses subnets in only one AZ. If that AZ becomes unavailable, the application stops serving requests. Which change most directly improves resilience to an AZ outage?

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.

A web application runs on an Amazon EC2 Auto Scaling group behind an Application Load Balancer (ALB). After each deployment, new instances take about 2 minutes to download artifacts and become ready to accept requests on the target port. In the last deployment, the ALB started marking targets unhealthy before the app was ready, and the Auto Scaling group then replaced those instances repeatedly, causing a prolonged outage. Which change best improves resilience during instance start-up without reducing actual availability once the application is healthy?

An order processing workflow uses Amazon SQS as the decoupling layer between a producer and a consumer Lambda function. The consumer intermittently fails due to a downstream dependency. The team has observed that certain “poison” messages keep being retried repeatedly and prevent other messages from being processed efficiently. Which SQS configuration most directly addresses this issue?

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.

A company runs the same public API in two regions (Region A and Region B), each fronted by an ALB. They want Route 53 to automatically route clients to the Region B API when Region A becomes unhealthy, with minimal configuration effort. Which Route 53 approach should they use?

A fintech startup uses AWS to run a web API and a PostgreSQL database. They must meet an RPO of 15 minutes and an RTO of 2 hours for a Region-wide disaster. Budget allows running a small, always-on set of infrastructure in a secondary Region, but not full production capacity. The team wants a DR approach that is regularly testable without large manual effort. Which disaster recovery strategy is the best fit?

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.

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.

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.

A media company stores original uploads in an S3 bucket. They must recover from accidental overwrites/deletes and also recover quickly from a full Region outage. The required RPO is about 1 hour. Which configuration best meets these requirements?

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?

A team wants a web application to keep serving traffic if one Availability Zone fails. Match each architecture element to the resilience behavior it provides.

A company is designing a disaster recovery plan for a critical application hosted on AWS. The application runs on EC2 instances with data stored in Amazon EBS volumes and Amazon S3. The recovery time objective (RTO) is 15 minutes, and the recovery point objective (RPO) is 1 hour. Which three strategies would help meet these objectives? (Choose three.)

A Multi-AZ Amazon RDS database experiences incorrect writes at 10:15 UTC due to a buggy release. The team detects the problem at 10:25 UTC. They want to restore the data to a known-good point around 10:15 UTC, and validate the recovered data, without taking the current production instance offline during the recovery process. What is the most appropriate AWS action?

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?

A company is designing a multi-Region disaster recovery (DR) strategy for a stateless web application running on Amazon EC2 instances behind an Application Load Balancer (ALB). The application uses an Amazon RDS for MySQL database as its data store. The architecture must provide rapid failover with the lowest possible Recovery Point Objective (RPO) and Recovery Time Objective (RTO). Which of the following design choices will help achieve these objectives? (Choose four.)

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.

An order system receives events and uses a Lambda function to write each order into a database. During traffic spikes, the database sometimes throttles, and Lambda retries lead to occasional message loss in the event flow. The team wants buffering, automatic retries, and a way to isolate messages that repeatedly fail so they can be inspected later. What design change best meets this need?

A company runs a customer portal on an Amazon Aurora PostgreSQL cluster. The application currently connects directly to the writer instance endpoint and keeps long-lived connections open. During a maintenance failover, writes fail until clients are restarted. The team wants the application to reconnect to the correct Aurora endpoint automatically and reduce user-visible write interruptions. Which change is most likely to achieve this?

Your ecommerce app runs behind an Application Load Balancer (ALB) and uses an RDS database for orders. During an AZ impairment in us-east-1, customers report that checkout takes several minutes to recover. The current design places EC2 instances only in private subnets of AZ-a, while the ALB spans multiple subnets. The RDS DB instance is Multi-AZ. Management wants automatic recovery within the same Region. Which change best addresses the issue with minimal operational overhead?

Your media processing pipeline writes original uploads to an S3 bucket and later generates derivative files. An operator accidentally deletes a subset of original uploads in production. You need to (1) restore the deleted objects with minimal data loss and (2) protect against both regional disasters and future operator mistakes. The company requires recovery even if objects are deleted and later overwritten. What is the most effective change to meet these requirements?