SOA-C02 Reliability and Business Continuity — 15 Questions

Question 1

An application uses an Amazon DynamoDB table with on-demand capacity. The SysOps administrator needs to ensure the table remains available during an AWS regional outage. Which strategy should be used?

Accepted Answer

Use DynamoDB global tables.. DynamoDB global tables provide multi-region, multi-active replication, ensuring the table remains available during an AWS regional outage by automatically replicating data across selected AWS Regions. This is the only option that addresses regional fault tolerance by design, as it uses DynamoDB's built-in replication to maintain availability and data durability across regions.

Answer

Enable DynamoDB Accelerator (DAX).

Answer

Create a read replica in another region.

Answer

Increase read and write capacity units.

Question 2

A SysOps administrator is testing the failover of an Amazon RDS for PostgreSQL Multi-AZ DB instance. The application currently writes to the primary instance in us-east-1a. Which action will manually trigger a failover to the standby instance in us-east-1b?

Accepted Answer

Reboot the DB instance and select 'Reboot with failover'.. The 'Reboot with failover' option in the Amazon RDS console explicitly triggers a failover by rebooting the primary DB instance and forcing the Multi-AZ configuration to promote the standby instance in us-east-1b to become the new primary. This is the designed method for manually testing or initiating a failover in a Multi-AZ deployment.

Answer

Modify the DB instance to Single-AZ and then back to Multi-AZ.

Answer

Reboot the DB instance without selecting any failover option.

Answer

Promote the standby instance using the Amazon RDS console.

Question 3

A company runs a web application on Amazon EC2 instances in a single Availability Zone. The SysOps administrator wants to increase the availability of the application so that it can survive an Availability Zone failure. Which action is the most effective?

Accepted Answer

Launch EC2 instances in two different Availability Zones and place them behind an Application Load Balancer.. Deploying EC2 instances across two different Availability Zones and placing them behind an Application Load Balancer (ALB) provides fault isolation. If one AZ fails, the ALB automatically routes traffic to the healthy instances in the other AZ, ensuring the application remains available. This architecture directly addresses the goal of surviving an AZ failure by eliminating the single point of failure at the AZ level.

Answer

Deploy an additional EC2 instance in the same Availability Zone.

Answer

Enable termination protection on all EC2 instances.

Answer

Use an Amazon RDS Multi-AZ deployment for the database tier.

Question 4

A company runs a critical production database on Amazon RDS for MySQL with a Multi-AZ deployment. The database experiences a primary instance failure. The SysOps administrator needs to understand exactly how the failover process worked and why the application experienced a longer-than-expected downtime. Which AWS service or feature should the administrator use to review detailed events and actions during the failover?

Accepted Answer

AWS Personal Health Dashboard. AWS Personal Health Dashboard provides a personalized view of the health of AWS services and resources, including detailed event logs for RDS Multi-AZ failovers. It surfaces the exact sequence of actions (e.g., DNS record update, failover initiation, completion) and any underlying AWS infrastructure issues that caused the extended downtime, such as degraded hardware or network latency. This is the correct tool because it gives the administrator a chronological, AWS-side account of the failover process, which is not available through other services.

Answer

Amazon RDS Performance Insights

Answer

Amazon CloudWatch Logs

Answer

AWS CloudTrail

Question 5

A company runs a stateless web application on Amazon EC2 instances in an Auto Scaling group with a minimum of 2 and maximum of 10 instances. The instances are behind an Application Load Balancer (ALB). The SysOps administrator needs to ensure that the application can survive the failure of an entire AWS Availability Zone (AZ) in the region. Which configuration is necessary?

Accepted Answer

Configure the Auto Scaling group with subnets in at least two Availability Zones and ensure the ALB has subnets in the same AZs.. Deploying the Auto Scaling group across multiple Availability Zones (AZs) and ensuring the ALB has subnets in the same AZs allows the application to continue serving traffic even if one entire AZ fails. The ALB can route requests to healthy instances in the remaining AZs, and the Auto Scaling group will replace failed instances in other AZs as needed, maintaining the minimum instance count. This architecture is a fundamental pattern for high availability in AWS.

Answer

Increase the Auto Scaling group minimum to 10 instances to absorb the failure.

Answer

Use larger instance types to handle the load of a failed AZ.

Answer

Use multiple Application Load Balancers in different AZs.

Question 6

A company runs a critical web application on Amazon EC2 instances in an Auto Scaling group across three Availability Zones in us-east-1. The application stores data in an Amazon RDS for MySQL DB instance with Multi-AZ deployment. The SysOps administrator needs to design a disaster recovery strategy that can recover from a complete regional outage. The Recovery Time Objective (RTO) is 2 hours and the Recovery Point Objective (RPO) is 1 hour. Which solution should the administrator implement?

Accepted Answer

Configure cross-region automated backups for the RDS instance with a backup window. Deploy an identical infrastructure stack in a second region using AWS CloudFormation StackSets. Create an Amazon Route53 DNS failover record set with health checks to automatically fail over to the second region.. It meets both the RTO of 2 hours and RPO of 1 hour. Cross-region automated backups for RDS provide an RPO of 1 hour or less by continuously backing up transaction logs to a secondary region. Deploying an identical infrastructure stack via CloudFormation StackSets ensures rapid provisioning in the secondary region, and Route53 DNS failover with health checks automates traffic redirection within the RTO window.

Answer

Create a read replica of the RDS instance in a second region. Configure an Amazon CloudFront distribution with the ALB as origin. Use Route53 failover routing policy to route traffic to the CloudFront distribution.

Answer

Take daily manual snapshots of the RDS instance and copy them to a second region. Store the AWS CloudFormation template for the infrastructure in an S3 bucket with cross-region replication. In the event of a disaster, manually deploy the stack and restore the snapshot.

Answer

Use AWS Database Migration Service (DMS) to continuously replicate data to a second region. Use an Application Load Balancer in the primary region and a Network Load Balancer in the secondary region. Create a Route53 weighted routing policy to distribute traffic.

Question 7

A company runs a critical application on Amazon EC2 instances with data stored on Amazon EBS volumes. The SysOps administrator needs to implement a backup strategy that supports point-in-time recovery with a Recovery Point Objective (RPO) of 1 hour and a Recovery Time Objective (RTO) of 4 hours. Which solution meets these requirements with the least operational overhead?

Accepted Answer

Use AWS Backup to schedule hourly EBS snapshots and restore to a new volume when needed.. AWS Backup provides a fully managed, policy-based backup service that can schedule EBS snapshots hourly, meeting the 1-hour RPO. Restoring from an AWS Backup snapshot to a new EBS volume and attaching it to an EC2 instance can be completed within the 4-hour RTO, with minimal operational overhead as it eliminates the need for custom scripts or lifecycle management.

Answer

Use Amazon Data Lifecycle Manager (DLM) to take hourly snapshots and create an AWS CloudFormation template to launch a new instance from the snapshot.

Answer

Use custom scripts to copy snapshots to an Amazon S3 bucket and restore from there.

Answer

Use Amazon S3 Lifecycle policies to transition data to Amazon S3 Glacier.

Question 8

A company runs a web application on two EC2 instances in different Availability Zones, each with an Elastic IP address. The SysOps administrator needs to automatically route traffic to the healthy instance and fail over if one instance becomes unhealthy. The application must be accessible via a single DNS name. Which Route 53 routing policy should be used?

Accepted Answer

Failover routing policy. The failover routing policy in Amazon Route 53 is designed to route traffic from a primary resource to a secondary resource when the primary becomes unhealthy. In this scenario, the two EC2 instances in different Availability Zones act as primary and secondary endpoints, and Route 53 uses health checks to monitor the primary instance. If the health check fails, Route 53 automatically fails over to the secondary instance, ensuring the application remains accessible via a single DNS name.

Answer

Weighted routing policy

Answer

Geolocation routing policy

Answer

Simple routing policy

Question 9

A company runs an Amazon RDS for MySQL DB instance in us-east-1. The SysOps administrator needs to implement a disaster recovery solution that can recover from a regional outage with a Recovery Point Objective (RPO) of less than 1 second and a Recovery Time Objective (RTO) of less than 1 minute. Which solution should the administrator use?

Accepted Answer

Aurora Global Database. Aurora Global Database is the correct choice because it provides a fully managed cross-region replication solution with a typical RPO of less than 1 second and an RTO of less than 1 minute during a regional failover. It uses a primary cluster in one region and up to five secondary clusters in other regions, with asynchronous replication that is optimized for low latency, meeting the stringent RPO/RTO requirements.

Answer

Multi-AZ deployment

Answer

Cross-region read replica

Answer

Automated snapshot copy to another region

Question 10

A company has an Amazon RDS for PostgreSQL DB instance with Multi-AZ deployment in us-east-1. The SysOps administrator must design a disaster recovery strategy to recover from a regional outage. The Recovery Time Objective (RTO) is 1 hour and the Recovery Point Objective (RPO) is 5 minutes. Which solution meets these requirements at the lowest cost?

Accepted Answer

Create a Read Replica in a different region and promote it during a disaster.. A cross-region Read Replica meets the RPO of 5 minutes because replication is continuous (asynchronous) with minimal lag, and the RTO of 1 hour is achievable by promoting the replica during a disaster. This is the lowest-cost option because it uses a single standby instance in another region without the overhead of a full Multi-AZ deployment or frequent snapshot transfers.

Answer

Take daily snapshots and copy them to another region.

Answer

Use cross-region automated backups.

Answer

Deploy a second Multi-AZ DB instance in another region.

Question 11

A company runs a critical application on Amazon EC2 instances. The application uses an NFS file system stored on an Amazon EFS file system. The SysOps administrator must ensure that the file system is highly available and can withstand an Availability Zone failure. The file system must be accessible from all Availability Zones in the region. Which configuration is required to meet these requirements?

Accepted Answer

Configure the EFS file system for Standard storage class and mount it using the regional DNS name.. The EFS Standard storage class replicates data across multiple Availability Zones (AZs) within a region, providing high availability and resilience against an AZ failure. Mounting the file system using the regional DNS name ensures that clients in any AZ can reach the file system via the nearest mount target, as the regional DNS name resolves to the mount target IP addresses in the local AZ. This configuration meets the requirement for the file system to be accessible from all AZs in the region while withstanding an AZ outage.

Answer

Configure the EFS file system for One Zone storage class and mount it using the file system ID.

Answer

Configure EFS to use provisioned throughput and mount it using a mount target IP address.

Answer

Enable EFS lifecycle management to move files to Infrequent Access storage class.

Question 12

A company runs a critical database on an Amazon RDS for MySQL DB instance. The SysOps administrator needs to ensure that the database can survive a single Availability Zone failure with minimal downtime. Which configuration should the administrator implement?

Accepted Answer

Enable Multi-AZ deployment.. Multi-AZ deployment for Amazon RDS automatically provisions and maintains a synchronous standby replica in a different Availability Zone. If the primary AZ fails, Amazon RDS automatically fails over to the standby, typically within 60–120 seconds, minimizing downtime without manual intervention. This meets the requirement for surviving a single AZ failure with minimal downtime.

Answer

Enable automatic backups.

Answer

Deploy a read replica in a different AZ.

Answer

Take a manual snapshot and copy it to another AZ.

Question 13

A company stores critical data in an Amazon S3 bucket in the us-west-2 Region. The SysOps administrator needs to ensure that all objects are automatically replicated to another AWS Region for disaster recovery. The Recovery Point Objective (RPO) must be less than 15 minutes, and existing objects must also be replicated. Which S3 feature should the administrator use?

Accepted Answer

S3 Cross-Region Replication (CRR) with Replication Time Control (RTC). S3 Cross-Region Replication (CRR) with Replication Time Control (RTC) is the correct choice because it provides automatic, asynchronous replication of objects to a different AWS Region, meeting the RPO of less than 15 minutes by guaranteeing replication within 15 minutes for most objects (99.99% of objects are replicated within 15 minutes). Additionally, CRR can replicate existing objects when configured with the appropriate replication rule and batch operations, satisfying the requirement to replicate all objects.

Answer

S3 Same-Region Replication (SRR)

Answer

S3 Event Notifications with an AWS Lambda function to copy objects to another region

Answer

S3 Transfer Acceleration

Question 14

A company processes orders using an Amazon SQS standard queue. The order processing application occasionally fails to process a message. The SysOps administrator wants to ensure that any message that fails to be successfully processed after three attempts is automatically moved to a separate queue for manual review. Which SQS feature should be configured?

Accepted Answer

Configure a Dead Letter Queue (DLQ) with a redrive policy. A Dead Letter Queue (DLQ) with a configured redrive policy is the correct SQS feature to automatically move messages that have failed processing after a specified number of attempts (in this case, three) to a separate queue for manual review. The redrive policy defines the source queue, the DLQ, and the maximum receive count (maxReceiveCount) threshold. When a message is received from the source queue more times than the maxReceiveCount, SQS automatically redirects it to the DLQ, isolating problematic messages without manual intervention.

Answer

Increase the visibility timeout of the queue

Answer

Convert the queue to a FIFO queue

Answer

Enable redrive allow policy on the queue

Question 15

A company has an Amazon DynamoDB table with on-demand capacity mode. The SysOps administrator needs to ensure that the table can survive a regional outage. The table is currently in us-east-1. Which feature should be configured to achieve regional resilience with minimal data loss?

Accepted Answer

DynamoDB global tables. DynamoDB global tables provide multi-Region, fully replicated tables that automatically propagate writes to all configured Regions, enabling the table to survive a regional outage with minimal data loss. This feature uses DynamoDB Streams to replicate data asynchronously across Regions, offering recovery point objectives (RPO) of typically under one second. For the requirement of regional resilience, global tables are the correct choice because they maintain active copies in multiple AWS Regions.

Answer

DynamoDB Accelerator (DAX)

Answer

DynamoDB point-in-time recovery

Answer

DynamoDB auto scaling