Design Resilient Architectures

382 questions

All types382 Multiple choice195 Multiple select187

A company hosts a critical e-commerce web application at the apex domain `example.com`. The primary infrastructure is deployed behind an Application Load Balancer (ALB) in the `us-east-1` Region. To implement a disaster recovery plan, the company deploys a warm standby version of the application behind another ALB in the `us-west-2` Region. The company wants to configure Amazon Route 53 to route all traffic to `us-east-1` under normal conditions and automatically fail over to `us-west-2` if the primary application becomes unhealthy.

Which TWO configuration steps must a solutions architect take in Route 53 to meet these requirements? (Select TWO.)

Select all that apply

Create a Failover Alias record for the apex domain pointing to the primary ALB, configure it as Primary, and set Evaluate Target Health to Yes.

Create a Failover Alias record for the apex domain pointing to the standby ALB, configure it as Secondary, and set Evaluate Target Health to Yes.

Create a CNAME record for the apex domain pointing to the DNS name of the primary ALB, and configure a secondary CNAME record with a Failover policy pointing to the standby ALB.

Create Latency Alias records pointing to both ALBs, and configure Route 53 to route 100% of the traffic to the primary region during normal operations.

Create a Failover record for the primary ALB, and configure a Route 53 health check that monitors the RDS PostgreSQL read replica in us-west-2 to trigger failover upon database promotion.

Show answer & explanation

Answer: Create a Failover Alias record for the apex domain pointing to the primary ALB, configure it as Primary, and set Evaluate Target Health to Yes.; Create a Failover Alias record for the apex domain pointing to the standby ALB, configure it as Secondary, and set Evaluate Target Health to Yes.

Answer

To configure active-passive failover at the apex domain, create a primary Failover Alias record pointing to the primary ALB, and a secondary Failover Alias record pointing to the standby ALB. For both records, set 'Evaluate Target Health' to 'Yes' to enable automatic health evaluation of the ALBs.

To set up active-passive failover for an apex domain pointing to Application Load Balancers, Route 53 requires two Failover Alias records (one Primary and one Secondary) sharing the same record name. The apex domain (example.com) cannot use CNAME records due to DNS specifications, so Alias records must be used. Setting 'Evaluate Target Health' to Yes on these Alias records allows Route 53 to automatically inherit the health status of the load balancers without requiring manual health check configurations.

Step-by-Step Solution

Select the apex domain in the Route 53 hosted zone and create a new record set.

A record set configuration window is opened for the zone apex (example.com).

The apex domain requires direct configuration of Alias records since CNAME records cannot exist at the zone apex.

Configure the primary record as an Alias to the primary Application Load Balancer in us-east-1, set the routing policy to Failover, select Primary as the failover type, and enable 'Evaluate Target Health'.

The primary record is configured to route all traffic to the us-east-1 ALB under normal operating conditions and monitor its health.

This establishes the active path and ensures Route 53 is aware of the health of the primary region's ALB.

Configure the secondary record as an Alias to the standby Application Load Balancer in us-west-2, set the routing policy to Failover, select Secondary as the failover type, and enable 'Evaluate Target Health'.

The secondary record is configured to receive traffic only when the primary record is determined to be unhealthy.

This establishes the passive failover path to the warm standby region when the primary region is unavailable.

Key Concept

Route 53 active-passive DNS failover configuration at the zone apex requires Primary and Secondary Failover Alias records pointing to the respective regional resources, with health evaluation enabled.

Estimated Time:2m 0s

Question 2Question →

A company hosts its main portal at the apex domain `example.com`. The application runs on Amazon EC2 instances behind an Application Load Balancer (ALB) in the `us-east-1` Region. The company wants to implement an active-passive disaster recovery strategy. If the ALB or the primary application becomes unhealthy, users must be redirected to a static maintenance page hosted on an Amazon S3 bucket configured for website hosting in the `us-west-2` Region. The database backend requires manual failover, so DNS routing must strictly route all users to the primary ALB under normal operations and only to the S3 bucket during a failure. Which two configurations should the solutions architect implement to meet these requirements?

Select all that apply

Create a Route 53 Failover Alias record for `example.com` pointing to the Application Load Balancer in `us-east-1`, set the Failover Record Type to Primary, and set Evaluate Target Health to Yes.

Create a Route 53 Failover Alias record for `example.com` pointing to the Amazon S3 static website endpoint in `us-west-2`, set the Failover Record Type to Secondary, and set Evaluate Target Health to No.

Create a Route 53 Latency Alias record for `example.com` pointing to the Application Load Balancer in `us-east-1` and set Evaluate Target Health to Yes to dynamically route users.

Create a CNAME record for `example.com` pointing to the Application Load Balancer DNS name, and configure a Route 53 HTTP health check to monitor the backend instances.

Create a Route 53 Failover record pointing to the Amazon RDS Read Replica, allowing Route 53 to automatically promote the replica to primary if the master database fails.

Show answer & explanation

Answer: Create a Route 53 Failover Alias record for `example.com` pointing to the Application Load Balancer in `us-east-1`, set the Failover Record Type to Primary, and set Evaluate Target Health to Yes.; Create a Route 53 Failover Alias record for `example.com` pointing to the Amazon S3 static website endpoint in `us-west-2`, set the Failover Record Type to Secondary, and set Evaluate Target Health to No.

Answer

Create a Route 53 Failover Alias record for the apex domain pointing to the Application Load Balancer in the primary region, set the record type as Primary, and enable Evaluate Target Health. Additionally, create a Route 53 Failover Alias record pointing to the S3 static website endpoint, set the record type as Secondary, and disable Evaluate Target Health.

To establish an active-passive failover for an apex domain, the solutions architect must configure Route 53 Failover Alias records. The Primary record points to the Application Load Balancer with Evaluate Target Health set to Yes. This configuration allows Route 53 to evaluate the health of the ALB and failover if the ALB is unhealthy. The Secondary record points to the S3 bucket website endpoint with Evaluate Target Health set to No, since the bucket serves as the static maintenance page and does not require further health validation.

Step-by-Step Solution

Determine the apex domain record requirements

Identify that the zone apex (`example.com`) cannot use a CNAME record, necessitating the use of Route 53 Alias records.

DNS standards prevent mapping a CNAME record directly to the root of a domain.

Configure the primary routing policy

Create a Failover Alias record pointing to the primary Application Load Balancer (ALB) and enable Evaluate Target Health.

This allows Route 53 to determine the health of the ALB using its built-in health indicators and dynamically failover when necessary.

Configure the backup routing policy

Create a Secondary Failover Alias record pointing to the Amazon S3 static website endpoint and disable Evaluate Target Health.

Disabling Evaluate Target Health on the secondary endpoint ensures traffic is successfully directed to the maintenance page during a failover event, without checking the health of the static page itself.

Key Concept

Route 53 active-passive DNS failover using Alias records at the zone apex

Question 3Question →

An enterprise is migrating a legacy customer management API to AWS. The API runs on a cluster of Amazon EC2 instances in a private subnet, configured to listen on port 8080. An Application Load Balancer (ALB) is deployed in public subnets to distribute incoming traffic. The application needs to dynamically scale based on demand while maintaining high availability. Traffic to the backend instances must be securely restricted, and the load balancer must accurately determine target health. Which two configurations should the solutions architect implement to satisfy these requirements? (Select two.)

Select all that apply

Configure the target group to route traffic to port 8080 and set the health check port to use the traffic port.

Configure the security group of the EC2 instances to allow inbound traffic on port 8080 from the security group of the Application Load Balancer.

Configure the target group health check to query the default port 80 to ensure the web server is listening, while routing main traffic to port 8080.

Create a Network ACL on the private subnet that allows inbound traffic on port 8080 from the security group of the Application Load Balancer.

Configure an Amazon Route 53 latency-based routing policy to direct client requests directly to the private EC2 instances to handle the scaling load.

Show answer & explanation

Answer: Configure the target group to route traffic to port 8080 and set the health check port to use the traffic port.; Configure the security group of the EC2 instances to allow inbound traffic on port 8080 from the security group of the Application Load Balancer.

Answer

To support an application running on port 8080, the target group must route traffic to port 8080 with the health check port matching the traffic port, and the EC2 instances' security group must allow inbound traffic on port 8080 from the security group of the Application Load Balancer.

To support an application running on port 8080, the target group must route traffic to port 8080 and its health checks must target the same port (or 'traffic-port') to ensure accurate status reporting. Additionally, to secure the architecture, the EC2 instances' security group should allow inbound traffic on port 8080 specifically from the security group of the Application Load Balancer.

Step-by-Step Solution

Configure the ELB Target Group mapping.

The target group is set to route requests to backend instances on port 8080.

Since the legacy API is configured to listen on port 8080, the ALB needs to target that specific port.

Align target health check port configuration.

The target group health checks query port 8080 (the traffic port).

Matching the health check port to the traffic port ensures that the load balancer correctly detects application availability without causing false unhealthy states.

Configure instance security group rules.

The EC2 instances' security group is restricted to allow port 8080 traffic only from the ALB's security group.

This implements the principle of least privilege by securing the backend instances so they can only receive traffic originating from the load balancer.

Key Concept

Integrating Elastic Load Balancing (ELB) with backend EC2 targets requires matching application ports for routing and health checks, and establishing secure path communications via security group chaining.

Estimated Time:2m 0s

Question 4Question →

A digital music distribution company hosts its core streaming platform in a primary AWS Region. The architecture consists of Amazon EC2 instances in an Auto Scaling group behind an Application Load Balancer, and an Amazon Aurora MySQL database. The company wants to set up a disaster recovery (DR) solution in a secondary AWS Region with a Recovery Time Objective (RTO) of 15 minutes and a Recovery Point Objective (RPO) of 5 minutes, while minimizing ongoing infrastructure costs.

Which combination of actions should the solutions architect implement to meet these requirements at the lowest cost? (Select TWO.)

Select all that apply

Configure an Amazon Aurora Global Database with the primary database cluster in the primary Region and a secondary database cluster in the secondary Region.

Deploy a Pilot Light environment in the secondary Region with an Auto Scaling group set to a minimum capacity of zero, and scale it up during a failover event.

Configure an Amazon Route 53 latency routing policy to route traffic between Regions without configuring health checks.

Back up the database daily to Amazon S3 Glacier Flexible Retrieval in the primary Region and copy the archives to the secondary Region.

Configure a standard Amazon RDS MySQL Multi-AZ deployment and use a read replica in the secondary Region as the main automatic failover target.

Show answer & explanation

Answer: Configure an Amazon Aurora Global Database with the primary database cluster in the primary Region and a secondary database cluster in the secondary Region.; Deploy a Pilot Light environment in the secondary Region with an Auto Scaling group set to a minimum capacity of zero, and scale it up during a failover event.

Answer

Configure an Amazon Aurora Global Database with a secondary cluster in the secondary Region, and deploy a Pilot Light environment in the secondary Region with an Auto Scaling group minimum capacity of zero.

The correct combination implements Amazon Aurora Global Database for sub-second cross-region data replication (satisfying the 5-minute RPO) and a Pilot Light environment in the secondary Region with compute resources set to a minimum capacity of zero (satisfying the 15-minute RTO at the lowest cost).

Step-by-Step Solution

Analyze the RPO requirement of 5 minutes to determine the database replication strategy.

Amazon Aurora Global Database provides sub-second cross-region replication, which easily satisfies the 5-minute RPO requirement.

Traditional backups or slower replication methods cannot meet a 5-minute recovery point objective.

Analyze the RTO requirement of 15 minutes and the goal of minimizing costs to determine the compute failover strategy.

A Pilot Light environment with an Auto Scaling group capacity set to zero ensures no running compute costs in the recovery Region while permitting new instances to spin up within 15 minutes.

A Warm Standby requires running active instances, which increases ongoing costs, while a Pilot Light meets both the recovery time and low-cost objectives.

Key Concept

Disaster Recovery (DR) strategies balancing RTO, RPO, and cost using Aurora Global Database and Pilot Light deployments.

Estimated Time:2m 0s

Question 5Question →

A global travel reservation platform hosts its application in the `us-east-1` Region. The architecture consists of an Amazon Aurora MySQL database cluster and a fleet of Amazon EC2 instances in an Auto Scaling group behind an Application Load Balancer (ALB). The platform needs to establish a disaster recovery (DR) plan in the `us-west-2` Region. The DR solution must achieve a Recovery Time Objective (RTO) of $15$ minutes and a Recovery Point Objective (RPO) of $2$ minutes, while minimizing ongoing running costs in the secondary region.

Which combination of actions should a solutions architect perform to meet these requirements? (Select TWO.)

Select all that apply

Create an Amazon Aurora Global Database with the primary cluster in `us-east-1` and a secondary cluster in `us-west-2`. In the event of a primary region outage, promote the secondary cluster to a standalone primary cluster.

Deploy an Application Load Balancer and an Auto Scaling group in `us-west-2` with minimum and desired capacities set to

1

. Configure Amazon Route 53 with failover routing and health checks to route traffic to the secondary load balancer.

Configure daily snapshots of the database cluster, copy them to Amazon S3 in `us-west-2`, and transition them to Amazon S3 Glacier Flexible Retrieval to minimize storage costs.

Configure Amazon Route 53 with latency-based routing to split client traffic equally between `us-east-1` and `us-west-2` without health checks, and maintain identical EC2 running capacity in both regions.

Deploy a standard Amazon RDS for MySQL database in `us-east-1` with a Read Replica in `us-west-2`, and rely on Amazon RDS to automatically fail over and redirect application write traffic to the Read Replica during a regional outage.

Show answer & explanation

Answer: Create an Amazon Aurora Global Database with the primary cluster in `us-east-1` and a secondary cluster in `us-west-2`. In the event of a primary region outage, promote the secondary cluster to a standalone primary cluster.; Deploy an Application Load Balancer and an Auto Scaling group in `us-west-2` with minimum and desired capacities set to $1$ . Configure Amazon Route 53 with failover routing and health checks to route traffic to the secondary load balancer.

Answer

Create an Amazon Aurora Global Database to replicate the database, and maintain a scaled-down Pilot Light compute tier in the secondary region with Route 53 failover routing.

Aurora Global Database replicates data across regions with latency under

1

second, satisfying the

2

-minute RPO. In a disaster, the secondary cluster can be promoted to a standalone primary cluster in less than

1

minute. Maintaining a scaled-down Auto Scaling group (Pilot Light) with a capacity of

1

in the secondary region minimizes ongoing costs while ensuring the infrastructure is ready to scale up within the

15

-minute RTO when Route 53 routes traffic there.

Step-by-Step Solution

Determine the database replication mechanism that meets the RPO of

2

minutes.

Aurora Global Database provides asynchronous replication with typical latency of less than

1

second, which fits the requirement.

Choosing a high-performing database replication technology is necessary to ensure data is constantly synchronized without violating the recovery point objective.

Determine the compute recovery strategy that meets the RTO of

15

minutes while minimizing running costs.

A Pilot Light strategy with an Auto Scaling group having a minimum/desired capacity of

1

keeps costs low while allowing rapid scaling when DNS failover is triggered.

Maintaining active but scaled-down services ensures that the endpoint infrastructure is online, which speeds up failover compared to building from backups.

Configure Amazon Route 53 failover routing with health checks.

DNS requests will resolve to the primary region under normal conditions and automatically redirect to the secondary region if the primary region becomes unhealthy.

Automatic failover requires health monitoring and dynamic DNS resolution routing policies to minimize manual intervention and meet the RTO.

Key Concept

Disaster Recovery (DR) strategies using Aurora Global Database and Pilot Light compute scaling across AWS Regions.

Question 6Question →

A company is designing a fleet management system that receives diagnostic alerts from vehicles. When an alert is received, it must be sent to two separate applications: a real-time notification service and a maintenance scheduling service. The system must decouple the alert reception from the processing services and handle traffic spikes without losing messages. Strict ordering of the alerts is not required.

Which combination of AWS services should a solutions architect choose to meet these requirements? (Select TWO.)

Select all that apply

Amazon Simple Notification Service (Amazon SNS) to fan out the alerts to multiple destination queues.

Amazon Simple Queue Service (Amazon SQS) standard queues to buffer the alerts for each processing service.

Amazon SQS FIFO queues to guarantee that all alerts are processed in the exact order they are received.

Amazon Route 53 with latency-based routing to distribute the alerts directly to the processing instances.

Show answer & explanation

Answer: Amazon Simple Notification Service (Amazon SNS) to fan out the alerts to multiple destination queues.; Amazon Simple Queue Service (Amazon SQS) standard queues to buffer the alerts for each processing service.

Answer

Amazon Simple Notification Service (Amazon SNS) to fan out the alerts to multiple destination queues, and Amazon Simple Queue Service (Amazon SQS) standard queues to buffer the alerts for each processing service.

To send the same event to multiple downstream systems and decouple them, the solutions architect should use the SNS-to-SQS fan-out pattern. Amazon SNS publishes the event once, and standard Amazon SQS queues subscribed to the SNS topic receive a copy of the message. This decouples the services, buffers the messages to handle traffic spikes, and avoids the unnecessary complexity of FIFO queues since ordering is not required.

Step-by-Step Solution

Analyze the requirements for decoupling and fan-out.

The alerts must be processed by two separate services independently (fan-out pattern) and decoupled to handle traffic spikes.

Identifying the patterns needed determines the correct architectural components.

Select the fan-out component.

Amazon SNS is selected to receive the alert and publish it to multiple destinations.

SNS is the standard AWS service for pub/sub messaging and fan-out patterns.

Select the buffering and queuing component.

Amazon SQS standard queues are selected to buffer the alerts for each subscriber service.

SQS standard queues provide message buffering, decoupling, and high throughput without requiring strict ordering.

Key Concept

The combination of Amazon SNS and Amazon SQS (fan-out pattern) allows messages to be sent to multiple destination queues, enabling decoupled, scale-resilient parallel processing without strict ordering requirements.

Question 7Question →

A smart home IoT telemetry company runs its device monitoring platform in the us-east-1 Region. The database tier uses Amazon RDS for PostgreSQL. The compute tier runs on Amazon EC2 instances in an Auto Scaling group behind an Application Load Balancer. The company needs to design a disaster recovery (DR) plan in the us-west-2 Region. The design must achieve a Recovery Point Objective (RPO) of 5 minutes and a Recovery Time Objective (RTO) of 30 minutes, while keeping costs as low as possible. Which combination of actions should a solutions architect recommend to meet these requirements? (Select TWO.)

Select all that apply

Configure a cross-region read replica of the database in the secondary Region, and promote the replica to a standalone DB instance during a failover event.

Maintain a warm standby compute environment in the secondary Region with a scaled-down Auto Scaling group of EC2 instances, and scale it up to handle production traffic during a failover.

Deploy an RDS Multi-AZ deployment across the primary and secondary Regions to provide synchronous database replication and automatic failover.

Configure Amazon Route 53 with latency-based routing to automatically route traffic to the secondary Region without configuring health checks.

Export PostgreSQL database backups to Amazon S3 Glacier Deep Archive every 5 minutes, and restore the database from the backup during a failover.

Show answer & explanation

Answer: Configure a cross-region read replica of the database in the secondary Region, and promote the replica to a standalone DB instance during a failover event.; Maintain a warm standby compute environment in the secondary Region with a scaled-down Auto Scaling group of EC2 instances, and scale it up to handle production traffic during a failover.

Answer

The correct combination of actions is to configure a cross-region read replica of the database in the secondary Region, promoting it to a standalone DB instance during failover, and to maintain a warm standby compute environment in the secondary Region with a scaled-down Auto Scaling group of EC2 instances, scaling it up to handle production traffic during failover.

The correct strategy combines a database cross-region read replica and a warm standby compute environment. The cross-region read replica replicates data asynchronously, meeting the 5-minute RPO, and can be promoted to primary within minutes. A warm standby compute tier runs at a minimal capacity to reduce costs, and can be scaled out within 30 minutes to satisfy the RTO.

Step-by-Step Solution

Analyze the disaster recovery objectives: RPO is 5 minutes, and RTO is 30 minutes.

The replication lag must be under 5 minutes, and the recovery process (database promotion and compute scaling) must take less than 30 minutes.

This establishes the boundaries for data replication and infrastructure restoration speed.

Select the database replication strategy.

An Amazon RDS cross-region read replica provides asynchronous replication with low lag (meeting RPO) and can be promoted quickly (meeting RTO). RDS Multi-AZ is rejected because it is limited to a single Region.

Choosing the database configuration that provides cross-region capabilities is necessary to meet both RPO and RTO constraints.

Select the compute recovery strategy.

A warm standby compute environment keeps a scaled-down Auto Scaling group running in the secondary Region, keeping costs low while allowing quick scale-up during failover to meet the RTO.

This ensures the compute capacity is ready to serve traffic within the 30-minute RTO window without incurring the full cost of an active-active setup.

Key Concept

Disaster recovery strategies differ in RTO, RPO, and cost. A warm standby approach combined with cross-region read replicas provides a cost-effective solution for low RTO and RPO requirements across AWS Regions.

Question 8Question →

A ride-sharing platform is designing an event-driven system to process ride status updates (such as requested, accepted, driver_arrived, and ride_ended) sent from driver mobile applications. To maintain a correct trip history, updates for each specific ride must be processed in the exact sequence they are generated. The platform must handle sudden spikes in traffic during peak hours without losing messages, and the upstream ingestion layer must be decoupled from the downstream processing application. Which solution meets these requirements with the least operational overhead?

Publish the updates to a standard Amazon SNS topic. Subscribe a standard Amazon SQS queue to the topic, and configure the downstream application to process messages from the queue, relying on the queue's default configuration to preserve ordering.

Ingest the updates through an Amazon Kinesis Data Firehose delivery stream, configure it to buffer the events, and write them directly to an Amazon DynamoDB table with strong consistency enabled to ensure sequential updates.

Publish the updates to an Amazon SNS FIFO topic. Subscribe an Amazon SQS FIFO queue to the topic, and configure the downstream application to process messages from the queue using the ride ID as the message group ID.

Store the incoming updates in an Amazon ElastiCache for Redis cluster, and write a custom multi-threaded application on Amazon EC2 to continuously poll the cache and process updates in sequence.

Show answer & explanation

Answer: Publish the updates to an Amazon SNS FIFO topic. Subscribe an Amazon SQS FIFO queue to the topic, and configure the downstream application to process messages from the queue using the ride ID as the message group ID.

Answer

The correct solution uses an Amazon SNS FIFO topic subscribed to by an Amazon SQS FIFO queue. SNS FIFO and SQS FIFO queues guarantee first-in, first-out (FIFO) delivery within a message group. By setting the ride ID as the message group ID, the platform ensures that updates for any single ride are processed in the order they were sent. This serverless solution handles scaling and message buffering automatically, minimizing operational overhead.

Step-by-Step Solution

Analyze the requirements for message ordering and decoupling.

Identified that the solution must guarantee strict ordering of messages per ride ID (sequence of status updates) and decouple upstream mobile apps from downstream processing.

This helps narrow down the choices to AWS messaging services that support FIFO (First-In-First-Out) capabilities.

Evaluate the capabilities of Amazon SNS and SQS for ordering.

Standard SNS and SQS queues do not guarantee ordering, whereas SNS FIFO and SQS FIFO queues guarantee strict ordering of messages within the same message group.

The ride ID must be used as the message group ID to ensure that messages belonging to the same ride are processed in sequence.

Select the option with the least operational overhead.

The serverless combination of SNS FIFO and SQS FIFO requires no infrastructure management and satisfies all decoupling and ordering constraints.

Custom solutions using ElastiCache or other databases require provisioning and management of compute resources, resulting in higher operational overhead.

Key Concept

Decoupling event-driven architectures requiring strict message ordering using SNS/SQS FIFO.

Question 9Question →

A logistics company is designing an event-driven delivery tracking system. Status updates for each delivery package must be processed in the exact chronological order in which they are generated by drivers. The updates need to be delivered to two separate systems: an analytics dashboard that requires strict ordering of events per package, and an audit service that does not require ordered processing. The solution must scale to handle traffic spikes during peak hours without losing any updates.

Which combination of actions should a solutions architect take to meet these requirements? (Select TWO.)

Select all that apply

Create an Amazon SNS FIFO topic to receive the updates, and subscribe an Amazon SQS FIFO queue to the topic for the analytics dashboard.

Subscribe an Amazon SQS Standard queue to the Amazon SNS FIFO topic for the audit service.

Create an Amazon SNS Standard topic to receive the updates, and subscribe Amazon SQS FIFO queues to the topic for both the analytics dashboard and the audit service.

Create an Amazon SQS Standard queue to receive the updates, and configure both the analytics dashboard and the audit service to consume messages from the same queue.

Show answer & explanation

Answer: Create an Amazon SNS FIFO topic to receive the updates, and subscribe an Amazon SQS FIFO queue to the topic for the analytics dashboard.; Subscribe an Amazon SQS Standard queue to the Amazon SNS FIFO topic for the audit service.

Answer

Create an Amazon SNS FIFO topic and subscribe an Amazon SQS FIFO queue to it for the ordered analytics dashboard, and subscribe an Amazon SQS Standard queue to the same SNS FIFO topic for the unordered audit service.

To preserve message ordering during a fan-out pattern, an Amazon SNS FIFO topic must be used. SQS FIFO queues can be subscribed to the SNS FIFO topic to receive messages in chronological order, satisfying the requirements of the analytics dashboard. SQS Standard queues can also be subscribed to the same SNS FIFO topic, which satisfies the audit service's requirement since it does not need ordered processing.

Step-by-Step Solution

Identify the ordering requirements and fan-out architecture.

The analytics dashboard requires strict chronological order per package, while the audit service can process updates out of order. Both must receive all updates, necessitating a fan-out pattern.

This establishes that we need a messaging service capable of fan-out (such as Amazon SNS) combined with queuing (Amazon SQS) to decouple the publishers and subscribers.

Select the appropriate Amazon SNS topic type.

Choose Amazon SNS FIFO because it guarantees message ordering and deduplication, and supports delivering to SQS FIFO queues.

Standard SNS topics do not guarantee ordering and cannot deliver to SQS FIFO queues.

Select and subscribe the queues for each consumer.

Subscribe an Amazon SQS FIFO queue to the SNS FIFO topic for the ordered analytics dashboard. Subscribe an Amazon SQS Standard queue to the same SNS FIFO topic for the unordered audit service.

This setup preserves ordering for the dashboard through the end-to-end FIFO path while allowing the audit service to consume messages using a standard queue, since ordering is not required for auditing.

Key Concept

FIFO Fan-out using SNS FIFO and SQS FIFO/Standard

Question 10Question →

An organization hosts a legacy payroll application on Amazon EC2 instances managed by an Auto Scaling group (ASG) behind an Application Load Balancer (ALB). The payroll application runs on port 8088. The target group is configured to route HTTP traffic to the EC2 instances on port 8088. The EC2 instances are in a security group that allows inbound traffic on port 8088 from the ALB's security group. However, the ALB marks all registered EC2 instances as unhealthy. A solutions architect discovers that the target group's health checks are configured to use HTTP on port 80. How should the solutions architect resolve this issue and restore the system to a healthy state?

Configure the target group's health check port to use port 80 to match standard HTTP configurations.

Add an inbound rule to the EC2 instances' security group to allow return traffic on ephemeral ports from the ALB, as security groups are stateless.

Modify the target group's health check settings to use port 8088 or set the health check port to traffic-port.

Configure an Amazon Route 53 latency routing policy to route traffic directly to the EC2 instances instead of the ALB to bypass the target group health checks.

Show answer & explanation

Answer: Modify the target group's health check settings to use port 8088 or set the health check port to traffic-port.

Answer

Modify the target group's health check settings to use port 8088 or set the health check port to traffic-port.

The correct option is to modify the target group's health check settings to use port 8088 or 'traffic-port'. By default, the ALB target group health check uses the port configured for traffic routing ('traffic-port') unless overridden. If it was overridden to port 80, the health check requests will be sent to port 80 on the EC2 instances. Since the payroll application is listening on port 8088 and no service is listening on port 80, the health checks will fail. Correcting the health check port resolves this mismatch.

Step-by-Step Solution

Analyze the application listening port and the target group health check configuration.

The application is listening on port 8088, but health checks are being sent to port 80.

Identify the mismatch between where the service is active and where the load balancer is querying for health status.

Determine the impact of the configuration mismatch.

Since no process on the EC2 instances is listening on port 80, connection attempts by the ALB fail, and instances are marked unhealthy.

Explain why the instances are failing the health checks despite having security group rules permitting traffic on port 8088.

Align the health check port with the application port.

Change the health check port configuration to port 8088 or specify 'traffic-port' to dynamically match the target group's routing port.

Ensures the health check queries the port where the payload application is running, allowing successful health status updates.

Key Concept

ELB Target Group Health Check Port Configuration

Estimated Time:1m 30s

Question 11Question →

A company hosts a containerized backend application on Amazon EC2 instances in an Auto Scaling group (ASG) behind an Application Load Balancer (ALB). The application listens on custom port 8443, and the ALB terminates SSL/TLS on port 443. The solutions architect notices two issues: first, when instances fail internally, the ALB marks them as unhealthy, but the ASG continues to treat them as healthy and does not replace them; second, newly launched instances fail health checks immediately because traffic is blocked between the ALB and the instances. Which actions should the solutions architect take to resolve these issues and ensure a resilient architecture? (Select two.)

Select all that apply

Update the health check type of the Auto Scaling group from EC2 to ELB.

Configure the target group's health check to use port 8443, and ensure the EC2 instances' security group allows inbound traffic from the ALB security group on port 8443.

Modify the target group's health check to query the default HTTP port 80 to minimize processing overhead on the application's secure port.

Configure a stateless Network ACL on the subnet that allows inbound traffic on port 443 and blocks outbound ephemeral port traffic to secure the return path.

Establish an Amazon Route 53 latency routing policy pointing directly to the EC2 instances' public IP addresses to bypass the ALB during periods of high latency.

Show answer & explanation

Answer: Update the health check type of the Auto Scaling group from EC2 to ELB.; Configure the target group's health check to use port 8443, and ensure the EC2 instances' security group allows inbound traffic from the ALB security group on port 8443.

Answer

The correct actions are to update the health check type of the Auto Scaling group from EC2 to ELB, configure the target group's health check to use port 8443, and ensure the EC2 instances' security group allows inbound traffic from the ALB security group on port 8443.

To ensure that unhealthy application instances are replaced, the Auto Scaling group's health check type must be updated from EC2 to ELB so that target group health status changes trigger auto-replacement. Additionally, because the application runs on custom port 8443, the target group's health check must be explicitly set to port 8443, and the security group of the EC2 instances must allow inbound traffic from the ALB security group on port 8443.

Step-by-Step Solution

Analyze the Auto Scaling group health check settings.

Identify that EC2 health checks only monitor the hardware/hypervisor level, meaning application failures are ignored. Setting the ASG health check type to ELB aligns instance replacement with the ALB's status.

This guarantees that instances failing application-level checks are automatically terminated and replaced by the Auto Scaling group.

Verify communication paths and ports between the ALB and EC2 instances.

Confirm that the application listens on custom port 8443, meaning target group health checks must query 8443, and security groups must permit inbound traffic on port 8443 from the ALB security group.

This establishes a valid connection path for the ALB health checks, preventing newly launched healthy instances from being flagged as unhealthy.

Key Concept

Auto Scaling health check configurations and load balancer target group routing over custom ports.

Question 12Question →

A clinical diagnostic laboratory is building an event-driven system to process patient test results generated by multiple automated analyzers. The results for each patient must be processed in the exact sequence they are completed to prevent older results from overwriting newer ones due to network latency. Results for different patients can be processed concurrently. The system must scale automatically to handle sudden increases in test volumes during peak hours.

Which solution meets these requirements with the least operational overhead?

Create a standard Amazon SQS queue and configure an AWS Lambda function as the consumer. Implement sorting logic in the consumer application to order the results by patient ID before processing.

Configure the analyzers to directly invoke an AWS Lambda function for each event. Have the Lambda function execute a continuous polling loop to wait and collect all test results for a patient before processing them.

Create an Amazon SQS FIFO queue and configure an AWS Lambda function as the consumer. Send the events to the queue using the patient ID as the message group ID.

Create an Amazon Kinesis data stream. Configure the analyzers to write events to the stream using the analyzer machine ID as the partition key, and process the events using an AWS Lambda function.

Show answer & explanation

Answer: Create an Amazon SQS FIFO queue and configure an AWS Lambda function as the consumer. Send the events to the queue using the patient ID as the message group ID.

Answer

Create an Amazon SQS FIFO queue and configure an AWS Lambda function as the consumer. Send the events to the queue using the patient ID as the message group ID.

The correct solution uses an Amazon SQS FIFO queue with the patient ID as the message group ID. This setup guarantees that all messages belonging to the same patient (the same message group) are processed sequentially, while allowing different patient groups to be processed in parallel. Using AWS Lambda as a consumer provides automatic scaling and minimal operational overhead.

Step-by-Step Solution

Identify the primary requirement for message ordering and concurrency.

Events for the same patient must be processed in order, while events for different patients can be processed concurrently.

This dictates that we need a messaging system that supports message ordering groups.

Evaluate Amazon SQS FIFO queues for this scenario.

SQS FIFO queues preserve message order within a specific MessageGroupId.

Using patient ID as the MessageGroupId ensures that all events for a single patient are processed in the order they are received, while allowing concurrent processing of different patient IDs.

Compare SQS FIFO with SQS Standard and Amazon Kinesis.

Standard SQS does not guarantee ordering. Kinesis requires partition key design and manual shard scaling.

SQS FIFO provides a serverless, zero-overhead solution for message grouping and ordering, minimizing operational overhead.

Key Concept

Amazon SQS FIFO queues use the MessageGroupId parameter to group messages that must be processed in a strict sequence, allowing multiple consumers to process different message groups concurrently.

Question 13Question →

A company runs a high-traffic web application on a fleet of Amazon EC2 instances managed by an Auto Scaling group (ASG). The application is configured to listen on custom port 8080. The instances are registered with a target group behind an Application Load Balancer (ALB) that routes external traffic from port 443 to the target group. A solutions architect must configure health checks to ensure that the ASG accurately detects and replaces instances that fail at the application layer, while maintaining a secure and highly available setup.

Which configuration should the solutions architect implement?

Configure the target group to perform health checks on default port 80 to simplify load balancer configurations, while allowing the instances to process application requests on port 8080.

Modify the subnet Network ACL to allow inbound traffic on port 8080, and rely on the stateful nature of Network ACLs to automatically allow outbound ephemeral port return traffic to the Application Load Balancer.

Configure the target group health check to query the application's status path on port 8080, and update the Auto Scaling group to use Elastic Load Balancing (ELB) health checks. Ensure the security groups allow traffic from the ALB to the instances on port 8080.

Configure Route 53 with Latency routing to distribute incoming requests across multiple AWS Regions, using the latency policy as the primary mechanism to fail over and reroute traffic away from unhealthy EC2 instances without configuring Route 53 health checks.

Show answer & explanation

Answer: Configure the target group health check to query the application's status path on port 8080, and update the Auto Scaling group to use Elastic Load Balancing (ELB) health checks. Ensure the security groups allow traffic from the ALB to the instances on port 8080.

Answer

Configuring the target group health check to query the status path on port 8080 ensures that the ALB tests the actual application port. Setting the Auto Scaling group to use ELB health checks allows the ASG to terminate and replace instances that fail the ALB health checks, maintaining resilience at the application layer. Standard security group rules must also allow port 8080 traffic between the ALB and the instances.

Step-by-Step Solution

Configure the target group health check to match the application's listening port.

The target group is configured to query the custom application port (8080) instead of the default HTTP port (80).

The Application Load Balancer needs to verify the health of the application on the specific port where the application service runs, preventing false-negative health statuses.

Integrate the Auto Scaling Group health checks with the Elastic Load Balancer.

The Auto Scaling Group is updated to use ELB health checks in addition to standard EC2 instance status checks.

By default, the ASG only monitors EC2 status (e.g., hardware/hypervisor failures). Adding ELB health checks ensures the ASG replaces instances that fail at the application layer.

Establish secure network routing rules for health checks and traffic.

Security groups are configured to allow inbound traffic from the ALB on port 8080, and Network ACLs are configured to permit stateless ephemeral return traffic.

Security groups must allow communication between the load balancer and the targets, and stateless Network ACLs must explicitly allow return traffic to avoid blocking connections.

Key Concept

Aligning target group health checks with custom application ports, enabling ELB health checks in the Auto Scaling group, and satisfying stateful security group and stateless Network ACL rules.

Estimated Time:2m 0s

Question 14Question →

An IoT asset tracking platform for a cold chain logistics company runs its application tier on Amazon EC2 instances in an Auto Scaling group behind an Application Load Balancer in the us-east-1 Region. The database tier uses a Single-AZ Amazon RDS for PostgreSQL DB instance. The company needs to design a disaster recovery (DR) strategy in the us-west-2 Region that achieves a Recovery Point Objective (RPO) of $5$ minutes and a Recovery Time Objective (RTO) of $15$ minutes, while minimizing ongoing run costs. Which combination of actions should a solutions architect recommend to meet these requirements? (Select TWO.)

Select all that apply

Configure a cross-region read replica for the Amazon RDS for PostgreSQL DB instance in us-west-2 to replicate data asynchronously.

Configure Amazon RDS Multi-AZ replication directly between us-east-1 and us-west-2 to enable automatic, synchronous database failover to the secondary region.

Pre-deploy the Application Load Balancer in us-west-2, configure an Auto Scaling group with a minimum capacity of

1

instance, and use Amazon Route 53 failover routing with active health checks.

Deploy an Amazon Route 53 latency routing policy to distribute traffic across both regions, and use AWS CloudFormation to provision the Application Load Balancer and Auto Scaling group in us-west-2 from scratch upon detecting a failure.

Back up the database daily using AWS Backup, copy the recovery points to an Amazon S3 Glacier Flexible Retrieval vault in us-west-2, and restore the database to a new instance during a failover.

Show answer & explanation

Answer: Configure a cross-region read replica for the Amazon RDS for PostgreSQL DB instance in us-west-2 to replicate data asynchronously.; Pre-deploy the Application Load Balancer in us-west-2, configure an Auto Scaling group with a minimum capacity of $1$ instance, and use Amazon Route 53 failover routing with active health checks.

Answer

The correct strategy combines configuring an Amazon RDS for PostgreSQL cross-region read replica in the standby region with pre-deploying the Application Load Balancer and a scaled-down Auto Scaling group (minimum capacity of

1

instance) in that region, combined with Route 53 failover routing and health checks.

To meet both the

5

-minute RPO and

15

-minute RTO cost-effectively, a Warm Standby disaster recovery pattern is required. The database tier uses asynchronous cross-region read replication to keep replica lag under a few minutes, meeting the RPO. Promoting the replica to primary takes under

10

minutes. The compute tier pre-deploys the Application Load Balancer and keeps a minimum of

1

EC2 instance active in the Auto Scaling group, enabling immediate request handling upon failover and rapid scale-out, satisfying the RTO. Route 53 failover routing automatically detects primary region failure and routes traffic to the standby load balancer.

Step-by-Step Solution

Evaluate database disaster recovery options that satisfy the recovery objectives.

Confirm that an Amazon RDS cross-region read replica meets the

5

-minute RPO through asynchronous replication, and its promotion time meets the

15

-minute RTO.

Asynchronous replication across regions minimizes performance overhead on the primary database while keeping the standby database updated within seconds or minutes.

Determine the minimum compute deployment required in the secondary region to guarantee a failover time of less than

15

minutes.

Choose a Warm Standby pattern by pre-deploying the Application Load Balancer and running a minimum of

1

EC2 instance in the Auto Scaling group in the recovery region.

Deploying resources from scratch on failover (Pilot Light) takes too long to meet the

15

-minute RTO, whereas keeping a scaled-down compute tier active allows rapid scale-out and immediate request routing.

Configure DNS routing to handle failover automated detection.

Implement an Amazon Route 53 failover routing policy using health checks pointed at the primary region's resources.

Active health checks allow Route 53 to automatically detect a regional outage and redirect users to the pre-deployed standby load balancer in the secondary region.

Key Concept

Warm Standby Disaster Recovery Pattern

Question 15Question →

A financial subscription billing application runs on Amazon EC2 instances in an Auto Scaling group behind an Application Load Balancer in the us-east-1 Region. The application database is hosted on an Amazon RDS for PostgreSQL DB instance. The company wants to implement a disaster recovery (DR) strategy in the us-west-2 Region with a Recovery Time Objective (RTO) of less than 15 minutes and a Recovery Point Objective (RPO) of less than 5 minutes. The solution must minimize running costs under normal conditions. Which combination of actions should a solutions architect recommend to meet these requirements? (Select TWO.)

Select all that apply

Create an Amazon RDS for PostgreSQL cross-region read replica in the secondary region, and promote it to a standalone DB instance during a failover event.

Deploy an Application Load Balancer and a scaled-down Auto Scaling group of EC2 instances in the secondary region, and configure the group to scale up when a failover is initiated.

Enable Multi-AZ deployment for the RDS DB instance with a standby replica located in the secondary region to provide automatic, synchronous failover.

Use Amazon Route 53 latency routing to automatically redirect client requests to the secondary region during an outage without attaching health checks.

Store database transaction logs in an Amazon S3 Glacier Flexible Retrieval vault in the secondary region, and use expedited retrievals to restore the database during a failover.

Show answer & explanation

Answer: Create an Amazon RDS for PostgreSQL cross-region read replica in the secondary region, and promote it to a standalone DB instance during a failover event.; Deploy an Application Load Balancer and a scaled-down Auto Scaling group of EC2 instances in the secondary region, and configure the group to scale up when a failover is initiated.

Answer

To achieve the required RTO of under 15 minutes and RPO of under 5 minutes cost-effectively, configure an Amazon RDS cross-region read replica for database replication and deploy a scaled-down Auto Scaling group behind an Application Load Balancer in the secondary region to scale up during failover.

The correct strategy combines database replication and scaled-down compute resources. An RDS cross-region read replica maintains a replica of the database with sub-minute lag (RPO) and can be promoted to primary in minutes (RTO). A scaled-down Auto Scaling group in the secondary region acts as a Warm Standby, minimizing costs during normal operations while guaranteeing that application instances can scale up quickly during a disaster to meet the RTO.

Step-by-Step Solution

Address the database RPO and RTO constraints.

Deploy an Amazon RDS cross-region read replica.

Asynchronous cross-region replication keeps replication lag (RPO) within seconds. Promoting the read replica to a standalone primary database can be completed in a few minutes, meeting the 15-minute RTO.

Address the compute RTO and cost constraints.

Implement a Warm Standby pattern with a scaled-down Auto Scaling group and an Application Load Balancer in the disaster recovery region.

Maintaining a minimal number of running EC2 instances keeps idle costs low while ensuring the system can quickly scale up to production capacity, meeting the 15-minute RTO.

Key Concept

Cross-region disaster recovery strategies involving database replication and pre-provisioned scaled-down application infrastructure to meet specific RTO/RPO limits.

Estimated Time:2m 0s

Question 16Question →

A company is deploying a global application across two AWS Regions: us-east-1 and eu-central-1. The application consists of web servers behind an Application Load Balancer (ALB) in each region, and a multi-region database. The solutions architect needs to design an Amazon Route 53 DNS routing strategy that directs users to the closest region with the lowest network latency, but automatically redirects traffic to the other region if the ALB or the backend database in one region becomes unhealthy. Which combination of configurations should the solutions architect implement to meet these requirements? (Select TWO.)

Select all that apply

Create Route 53 Alias records with a Latency routing policy pointing to the ALB in each region, and configure Evaluate Target Health to Yes.

Configure the ALB target group health checks in each region to monitor an application health endpoint that verifies both the web server status and database connectivity.

Create Route 53 CNAME records with a Latency routing policy pointing to the ALB DNS names in each region, and enable Evaluate Target Health on these records.

Create Route 53 Failover routing records for both regions, designating the us-east-1 ALB as the primary record and the eu-central-1 ALB as the secondary record.

Create Route 53 Latency routing Alias records and manually configure the record TTL to 10 seconds to ensure faster client-side failover.

Show answer & explanation

Answer: Create Route 53 Alias records with a Latency routing policy pointing to the ALB in each region, and configure Evaluate Target Health to Yes.; Configure the ALB target group health checks in each region to monitor an application health endpoint that verifies both the web server status and database connectivity.

Answer

Create Route 53 Alias records with a Latency routing policy pointing to the ALB in each region with Evaluate Target Health set to Yes, and configure the ALB target group health checks to monitor a path that validates both the web server and database connectivity.

The correct architecture uses Route 53 Alias records with a Latency routing policy and 'Evaluate Target Health' enabled to route users based on lowest latency and monitor ALB health. To propagate database failures to Route 53, the ALB target group health check must monitor an endpoint that validates the backend database. When the database fails, the ALB targets fail health checks, causing the ALB to report as unhealthy, which prompts Route 53 to stop routing traffic to that region.

Step-by-Step Solution

Determine the appropriate Route 53 routing policy for lowest latency.

Latency routing policy must be used to direct users to the region that offers the lowest network latency.

Failover or other policies do not dynamically route based on latency performance.

Select the correct record type that supports health evaluation for the load balancer.

Use Alias records (pointing to the ALBs) instead of CNAME records, and enable 'Evaluate Target Health'.

'Evaluate Target Health' is only supported on Alias records and allows Route 53 to automatically monitor target group health.

Integrate the database status into the health check path.

Configure the ALB target group health check to query a deep health path (like `/health`) that verifies the backend database connection.

If the database goes down, target instances will fail their health checks, the ALB will report as unhealthy, and Route 53 will failover traffic.

Key Concept

Route 53 DNS failover using Latency routing policies combined with ALB Evaluate Target Health.

Estimated Time:2m 0s

Question 17Question →

A global media broadcasting corporation is designing a disaster recovery (DR) solution for its historical video archive system. The archive contains over $10\text{ PB}$ of footage that must be stored with maximum durability ( $99.999999999\%$ ) across multiple geographic locations to protect against regional disasters. In the event of a primary site failure, the company's business continuity plan dictates a Recovery Time Objective (RTO) of under $15\text{ minutes}$ to resume search and retrieval operations for the video files. Which storage and disaster recovery configuration meets these requirements?

Store the video archive in Amazon S3 Glacier Flexible Retrieval with Cross-Region Replication (CRR) enabled to a secondary Region. In the event of a disaster, use Standard Retrieval requests to access the archived video files, which requires

3\text{ to }5\text{ hours}

to complete.

Store the video archive in Amazon S3 Standard with Cross-Region Replication (CRR) enabled to a destination bucket in a secondary Region. Deploy a Warm Standby disaster recovery environment in the secondary Region with pre-provisioned, scaled-down catalog search services to meet the

15\text{-minute}

retrieval timeline.

Store the video archive in Amazon S3 Standard with Cross-Region Replication (CRR) enabled to a secondary Region. Use a Pilot Light disaster recovery strategy where all application servers in the secondary Region are kept stopped to minimize cost, resulting in a recovery process that exceeds the

15\text{-minute}

target.

Store the archive catalog in Amazon RDS for PostgreSQL. Configure a cross-Region Read Replica in the secondary Region, and rely on AWS-managed automatic failover to promote the Read Replica to the primary write instance within

15\text{-minutes}

during a regional outage.

Show answer & explanation

Answer: Store the video archive in Amazon S3 Standard with Cross-Region Replication (CRR) enabled to a destination bucket in a secondary Region. Deploy a Warm Standby disaster recovery environment in the secondary Region with pre-provisioned, scaled-down catalog search services to meet the $15\text{-minute}$ retrieval timeline.

Answer

Store the video archive in Amazon S3 Standard with Cross-Region Replication (CRR) and use a Warm Standby disaster recovery strategy in the secondary Region.

Storing the video archive in Amazon S3 Standard ensures that files are immediately accessible with sub-second retrieval latency, meeting the need for rapid search and recovery. Enabling Cross-Region Replication (CRR) asynchronously copies the data to a destination bucket in a secondary Region, achieving the required cross-region high availability and

99.999999999\%

durability. Implementing a Warm Standby disaster recovery strategy ensures that critical services (such as catalog search) are already running in a scaled-down capacity in the secondary Region, permitting failover to complete well within the

15\text{-minute}

RTO.

Step-by-Step Solution

Analyze storage durability and recovery time requirements.

Durability must be

99.999999999\%

across multiple Regions, and retrieval/recovery must happen within

15\text{ minutes}

(RTO).

This establishes S3 Standard as the appropriate storage tier since Glacier Standard retrieval times (

3\text{ to }5\text{ hours}

) exceed the RTO, and S3 Standard provides sub-second latency.

Evaluate replication options to satisfy the regional disaster recovery constraint.

Amazon S3 Cross-Region Replication (CRR) should be configured to replicate archive data asynchronously to a secondary AWS Region.

CRR protects the data against a regional outage while maintaining the required

99.999999999\%

durability of the S3 storage class.

Select the correct disaster recovery (DR) pattern for the catalog application and database.

A Warm Standby DR pattern is chosen, keeping a minimal, active catalog search application running in the recovery Region.

A Pilot Light pattern keeps resources stopped, which introduces startup latency that cannot reliably guarantee a failover in under

15\text{ minutes}

Key Concept

Disaster recovery planning requires balancing the storage tier's data retrieval speed against the application's Recovery Time Objective (RTO). High durability demands cross-Region replication, while low RTO demands warm, active standby infrastructure.

Estimated Time:2m 0s

Question 18Question →

A gaming company is launching a real-time multiplayer game. Players in North America and Europe must read and write their profiles and game state data with sub-second latency. The system must remain highly available even if an entire AWS Region suffers an outage, with a Recovery Time Objective (RTO) of less than 1 minute and a Recovery Point Objective (RPO) of near 0. Which database configuration should a solutions architect recommend to satisfy these requirements?

Deploy an Amazon RDS for MySQL DB instance in North America with Multi-AZ enabled. Create a cross-region read replica in Europe. Configure the game servers in Europe to write directly to the read replica to reduce latency, and promote the replica manually if the North America region fails.

Deploy a single-region Amazon Aurora MySQL database in North America. Set up Amazon Route 53 latency-based routing to dynamically route write requests from Europe players to the North America database, relying on the latency routing policy to handle failover to a backup database in Europe if the primary region goes offline.

Deploy an Amazon DynamoDB global table replicated between the North America and Europe regions. Use Amazon Route 53 latency-based routing combined with active health checks to direct user traffic to the closest healthy region.

Deploy an Amazon Aurora PostgreSQL Global Database with the primary cluster in North America and a secondary cluster in Europe. Configure a Pilot Light disaster recovery strategy where the secondary Europe cluster is kept in a shut-down state and is only provisioned and scaled up when a regional failover is triggered.

Show answer & explanation

Answer: Deploy an Amazon DynamoDB global table replicated between the North America and Europe regions. Use Amazon Route 53 latency-based routing combined with active health checks to direct user traffic to the closest healthy region.

Answer

The correct answer is the option that proposes deploying an Amazon DynamoDB global table replicated between the North America and Europe regions, along with Route 53 latency-based routing and health checks.

The correct answer is the option suggesting the deployment of an Amazon DynamoDB global table replicated between both regions using Route 53 latency-based routing and health checks. DynamoDB global tables support multi-region, active-active read and write operations. The data is replicated asynchronously with sub-second latency, providing near-zero RPO. Combined with Route 53 latency-based routing and health checks, client traffic is automatically routed to the closest healthy regional endpoint, allowing failover to complete in under a minute to satisfy the RTO constraint.

Step-by-Step Solution

Identify the latency and replication requirements.

The game requires active read and write operations with sub-second latency in both North America and Europe.

This indicates a need for a multi-region active-active database configuration, as single-region databases would introduce significant network latency for cross-region writes.

Evaluate the Recovery Time Objective (RTO) and Recovery Point Objective (RPO) constraints.

RTO must be less than 1 minute, and RPO must be near 0.

This requires automated failover capabilities and continuous, sub-second data replication across regions.

Match the requirements against AWS database services.

Amazon DynamoDB global tables provide fully managed, active-active multi-region replication with sub-second replication latency, meeting all performance, HA, and RTO/RPO requirements.

Relational databases like RDS and Aurora do not natively support active-active writes in multiple regions without write-forwarding latency or manual failover overhead.

Key Concept

Amazon DynamoDB Global Tables provide fully managed, active-active multi-region replication for high availability and low-latency local reads and writes.

Estimated Time:1m 30s

Question 19Question →

An insurance company runs its claims processing application in the us-east-1 Region. The application uses Amazon EC2 instances in an Auto Scaling group behind an Application Load Balancer, and an Amazon RDS for PostgreSQL DB instance. The company wants to design a disaster recovery (DR) plan in the us-west-2 Region. The DR strategy must achieve a Recovery Time Objective (RTO) of 1 hour and a Recovery Point Objective (RPO) of 15 minutes, while minimizing ongoing costs. Which combination of actions will meet these requirements? (Select TWO.)

Select all that apply

Configure a cross-region read replica of the RDS for PostgreSQL DB instance in the us-west-2 Region, and promote it to a standalone DB instance during failover.

Pre-stage an Application Load Balancer and an Auto Scaling group in the us-west-2 Region with the minimum capacity set to 0, and configure the Auto Scaling group to launch instances using replicated Amazon Machine Images (AMIs) during a failover.

Configure an Amazon RDS Multi-AZ deployment spanning both the us-east-1 and us-west-2 Regions to handle database replication and failover automatically.

Deploy a copy of the compute tier in the us-west-2 Region with the Auto Scaling group configured to run at full capacity to handle the application workload immediately.

Schedule daily database backups to an Amazon S3 bucket, configure S3 Cross-Region Replication to the us-west-2 Region with S3 Glacier Flexible Retrieval as the storage class, and restore the DB instance from the backup during failover.

Show answer & explanation

Answer: Configure a cross-region read replica of the RDS for PostgreSQL DB instance in the us-west-2 Region, and promote it to a standalone DB instance during failover.; Pre-stage an Application Load Balancer and an Auto Scaling group in the us-west-2 Region with the minimum capacity set to 0, and configure the Auto Scaling group to launch instances using replicated Amazon Machine Images (AMIs) during a failover.

Answer

To meet the requirements, the company should configure a cross-region read replica of the RDS for PostgreSQL DB instance in the secondary region and promote it to a standalone DB instance during failover, and pre-stage an Application Load Balancer and Auto Scaling group with a minimum capacity of 0 in the secondary region to launch instances using replicated AMIs when needed.

The correct combination of actions implements a cost-effective Pilot Light disaster recovery strategy. Creating an Amazon RDS cross-region read replica in the recovery region ensures that data is continuously and asynchronously replicated, maintaining a recovery point within minutes, which satisfies the 15-minute RPO. Pre-staging the Application Load Balancer and the Auto Scaling group with a minimum capacity of 0 ensures that no compute costs are incurred in the secondary region during normal operations. During a failover event, promoting the RDS read replica and scaling the compute instances up to the required capacity from replicated AMIs can be completed in under an hour, meeting the 1-hour RTO.

Step-by-Step Solution

Evaluate the database replication strategy to satisfy the Recovery Point Objective (RPO) of 15 minutes.

Using an Amazon RDS cross-region read replica provides asynchronous replication with lag times typically under a few minutes, meeting the 15-minute RPO.

Traditional backup and restore methods from daily snapshots cannot guarantee an RPO of less than 15 minutes, and RDS Multi-AZ cannot span multiple regions.

Evaluate the compute tier configuration in the secondary region to satisfy the Recovery Time Objective (RTO) of 1 hour while minimizing costs.

Pre-staging an Application Load Balancer and an Auto Scaling group with a minimum capacity of 0 ensures zero compute costs during normal operations (Pilot Light strategy). During failover, scaling the Auto Scaling group and launching instances from replicated AMIs takes only a few minutes, well within the 1-hour RTO.

Running a full-scale warm standby or active-active compute tier would incur substantial ongoing costs, which violates the constraint to minimize costs.

Key Concept

Disaster Recovery (DR) strategies involve finding the optimal balance between Recovery Time Objective (RTO), Recovery Point Objective (RPO), and cost. A Pilot Light strategy provides a cost-effective mechanism by keeping databases updated via asynchronous replication (RDS read replica) and keeping compute resources scaled down or pre-configured but not running (Auto Scaling group capacity 0).

Question 20Question →

An airline is designing an application to process loyalty rewards points accrual events. For each passenger, events must be processed in the exact chronological sequence they are generated to ensure loyalty tiers are calculated accurately. If an event fails to process after five attempts, it must be isolated for investigation without blocking the processing of events for other passengers.

Which solution meets these requirements with the least operational overhead?

Configure a standard Amazon SQS queue with an attached dead-letter queue. Set the passenger ID as a message attribute to guarantee that events for each passenger are processed in order.

Configure an Amazon SNS standard topic to receive the events, and subscribe multiple Amazon SQS FIFO queues to the topic to process messages for each passenger in order.

Configure an Amazon SQS FIFO queue with a dead-letter queue. Set the passenger ID as the message group ID to ensure in-order processing per passenger.

Configure an Amazon Kinesis Data Stream with a single shard to ingest all events, using the passenger ID as the partition key, and process events using an AWS Lambda consumer.

Show answer & explanation

Answer: Configure an Amazon SQS FIFO queue with a dead-letter queue. Set the passenger ID as the message group ID to ensure in-order processing per passenger.

Answer

Configure an Amazon SQS FIFO queue with a dead-letter queue. Set the passenger ID as the message group ID to ensure in-order processing per passenger.

The correct solution uses an Amazon SQS FIFO queue. SQS FIFO queues guarantee that messages within the same message group (using the passenger ID as the MessageGroupId) are processed in the exact order they are received. An associated dead-letter queue (DLQ) isolates messages that fail to process after five attempts, allowing other message groups (other passengers) to continue processing without interruption.

Step-by-Step Solution

Evaluate the ordering requirement.

Identified that events must be processed in the exact sequence they are generated on a per-passenger basis.

This requires a messaging mechanism that guarantees ordering based on a unique identifier (passenger ID) rather than requiring global ordering across all passengers.

Evaluate the failure isolation requirement.

Identified that failed events must be isolated after 5 retries without blocking other messages.

This indicates the need for a dead-letter queue (DLQ) with a maxReceiveCount of 5 configured on the source queue.

Compare SQS FIFO, SQS Standard, SNS standard, and Kinesis Data Streams capabilities.

SQS FIFO with a DLQ and a MessageGroupId of passenger ID satisfies all constraints with minimal configuration.

SQS Standard does not guarantee order, SNS Standard loses ordering before reaching the queues, and Kinesis with a single shard introduces scale limits and higher operational overhead.

Key Concept

Decoupling message processing using Amazon SQS FIFO queues to guarantee ordered processing within groups (using MessageGroupId) and utilizing dead-letter queues to handle processing failures without blocking other groups.

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