SOA-C02 Reliability and Business Continuity Practice Test 6 — 15 Questions

Question 1

A SysOps administrator is implementing a disaster recovery strategy for an S3 bucket containing critical data. The bucket must be available within 15 minutes if the primary region fails. Data must be replicated with RPO of less than 5 minutes. Which S3 replication configuration should be used?

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

Accepted Answer

Enable S3 Versioning and configure S3 Event Notifications to trigger a Lambda function that copies objects to another region. The correct choice because it can meet the RPO of less than 5 minutes by using S3 Event Notifications to trigger a Lambda function that copies objects to another region in near real-time. This approach allows for sub-5-minute replication, and the bucket is available within 15 minutes after failover. S3 Versioning ensures data integrity. While CRR with RTC guarantees replication within 15 minutes, it does not guarantee sub-5-minute RPO. Options A and C either replicate within the same region or are not suitable for continuous, near-real-time replication.

Answer

Enable S3 Versioning and S3 Same-Region Replication (SRR)

Answer

Enable S3 Versioning and transfer data to another region using AWS DataSync

Answer

Enable S3 Versioning and S3 Cross-Region Replication (CRR) with replication time control (RTC)

Question 2

A company uses Amazon Route 53 for DNS. They want to ensure that if the primary web server fails, traffic is automatically routed to a secondary server in another region. Which routing policy should be used?

Accepted Answer

Failover routing policy. The Failover routing policy in Amazon Route 53 is specifically designed for active-passive failover configurations. When the primary endpoint fails a health check, Route 53 automatically returns the secondary record in DNS responses, ensuring traffic is routed to the secondary server in another region. This directly meets the requirement for automatic failover between primary and secondary web servers.

Answer

Simple routing policy

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Latency routing policy

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Weighted routing policy

Question 3

A SysOps administrator notices that an RDS instance's storage is nearly full. The instance uses General Purpose SSD (gp2) storage. The administrator needs to increase storage with minimal downtime. Which action should be taken?

Accepted Answer

Modify the RDS instance to increase the allocated storage size. Modifying the RDS instance to increase the allocated storage size is the correct action because RDS for MySQL, MariaDB, PostgreSQL, Oracle, and SQL Server supports dynamic storage scaling with minimal downtime. When you modify the allocated storage for a gp2 volume, RDS performs the modification in the background, and the instance remains available during the process, though you may experience a brief performance impact. This directly addresses the near-full storage condition without requiring a full outage.

Answer

Enable storage auto-scaling

Answer

Delete old data to free up space

Answer

Convert the storage type to Provisioned IOPS

Question 4

A company runs a microservices architecture on Amazon ECS with Fargate. They need to ensure that if a task fails, it is automatically restarted. Which configuration is required?

Accepted Answer

Create an ECS service with a desired count and task definition. An ECS service with a desired count and task definition ensures that Fargate tasks are automatically restarted if they fail. The ECS service scheduler monitors the desired count and replaces any stopped or failed tasks to maintain the specified number of running instances, providing built-in resilience without additional infrastructure.

Answer

Configure a CloudWatch alarm to restart the task

Answer

Define tasks using the ECS RunTask API

Answer

Use an Auto Scaling group for the Fargate tasks

Question 5

A SysOps administrator is designing a highly available architecture for a web application using an Application Load Balancer (ALB) with EC2 instances in an Auto Scaling group. Which TWO configurations are required to ensure high availability? (Choose TWO.)

Accepted Answer

Configure the ALB with health checks for the target group. Health checks allow the ALB to monitor the status of each EC2 instance in the target group. If an instance fails health checks, the ALB automatically stops routing traffic to it, preventing user requests from reaching a failed instance. This is essential for maintaining application availability and is a core feature of the ALB's high-availability design.

Answer

Launch all EC2 instances in a single Availability Zone to reduce latency

Answer

Use t2.micro instances to reduce cost

Answer

Disable health checks to reduce load on the ALB

Question 6

A company runs a critical application on EC2 instances with EBS volumes. The SysOps administrator must ensure that EBS snapshots are taken every hour and retained for 7 days. Which THREE steps should be taken to achieve this? (Choose THREE.)

Accepted Answer

Create an IAM role for DLM with permissions to create and delete snapshots. AWS Data Lifecycle Manager (DLM) requires an IAM role with permissions to create, delete, and manage EBS snapshots on your behalf. This role is essential for DLM to automate snapshot creation and deletion according to the lifecycle policy. Without this role, DLM cannot perform the necessary actions on the EBS volumes.

Answer

Create a CloudWatch Events rule to trigger a Lambda function that creates snapshots

Answer

Use AWS Backup to create a backup plan with hourly frequency

Question 7

A company runs a web application on EC2 instances in an Auto Scaling group behind an Application Load Balancer. The application stores session data in an in-memory cache on the EC2 instances. During an instance refresh, users lose their session data. Which action should be taken to improve reliability without major application changes?

Accepted Answer

Move session state to Amazon ElastiCache for Redis.. Amazon ElastiCache for Redis provides a fully managed, external, and highly available in-memory data store that can be used to persist session state outside of the EC2 instances. By moving session data to Redis, the session state survives instance refreshes, terminations, or scaling events without requiring any changes to the application's session management logic beyond pointing to the Redis endpoint. This decouples session state from the compute layer, ensuring reliability and data durability during Auto Scaling lifecycle events.

Answer

Use ElastiCache for Memcached with auto-discovery.

Answer

Increase the minimum size of the Auto Scaling group.

Answer

Enable sticky sessions (session affinity) on the ALB target group.

Question 8

A company runs a production RDS for PostgreSQL instance with Multi-AZ enabled. The database experiences a failover due to an AZ outage. After the failover, the application experiences high latency on write operations. What is the most likely cause?

Accepted Answer

Synchronous replication to the standby instance in the other AZ is causing additional latency.. With Multi-AZ enabled, RDS for PostgreSQL uses synchronous replication to the standby instance in a different Availability Zone. After a failover, the new primary continues to use synchronous replication to the new standby, which adds latency to write operations because each write must be acknowledged by the standby before the primary commits. This synchronous replication overhead is the most likely cause of the increased write latency.

Answer

The application is now reading from the standby instance, which has higher read latency.

Answer

The failover switched to a read replica in a different AZ.

Answer

The failover switched to asynchronous replication mode.

Question 9

A SysOps administrator is designing a disaster recovery plan for a critical application that runs on EC2 instances with data stored on EBS volumes. The application requires an RPO of 15 minutes and an RTO of 2 hours. The current solution uses EBS snapshots taken every 6 hours. The administrator needs to improve the backup strategy to meet the RPO. What is the most cost-effective way to achieve this?

Accepted Answer

Increase the snapshot frequency to every 15 minutes.. Increasing the snapshot frequency to every 15 minutes directly reduces the recovery point objective (RPO) from 6 hours to 15 minutes, meeting the requirement without incurring additional infrastructure costs. EBS snapshots are incremental and cost-effective, as only changed blocks are stored after the initial snapshot, making frequent snapshots a practical approach for achieving a low RPO.

Answer

Enable EBS Recycle Bin with a retention rule of 15 minutes.

Answer

Change the EBS volume type to io2 Block Express.

Answer

Use EBS Multi-Attach to attach volumes to multiple instances for redundancy.

Question 10

A company runs a stateless web application on EC2 instances in an Auto Scaling group. The instances are behind an Application Load Balancer. The Auto Scaling group uses a dynamic scaling policy based on average CPU utilization. During a traffic spike, new instances are launched but take 5 minutes to become healthy. Users experience errors during this time. Which solution would reduce the time to serve traffic from new instances?

Accepted Answer

Use a launch template with a pre-provisioned AMI.. A pre-provisioned AMI eliminates the need for software installation and configuration at launch time, reducing the time for new EC2 instances to become healthy. By baking the application and dependencies into the AMI, instances can start serving traffic almost immediately after booting, rather than waiting for user data scripts or configuration management tools to complete.

Answer

Add a lifecycle hook to delay instance termination.

Answer

Increase the cooldown period for the scaling policy.

Answer

Use a larger instance type.

Question 11

An organization is using AWS CloudFormation to deploy infrastructure. The SysOps administrator needs to ensure that if a stack update fails, the stack automatically rolls back to the last known good state. Which stack update option should be configured?

Accepted Answer

Rollback on failure. CloudFormation's 'Rollback on failure' option, enabled by default, automatically reverts a stack to its last known good state if a stack update fails. This ensures that failed updates do not leave the infrastructure in an inconsistent or partially deployed state, maintaining reliability and business continuity.

Answer

Disable rollback

Answer

Change sets

Answer

Stack policy

Question 12

A company runs a critical database on an EC2 instance with an EBS volume. The administrator wants to create a disaster recovery plan that can recover the database in a different AWS Region within 4 hours. The database size is 1 TB. What is the MOST efficient approach to meet the RTO?

Accepted Answer

Copy the AMI and underlying EBS snapshots to the DR region.. Copying the AMI and its underlying EBS snapshots to the DR region creates a fully independent, bootable image that can be launched as an EC2 instance in the target region. This approach directly supports the 4-hour RTO by allowing the administrator to pre-stage the AMI copy or initiate the copy on-demand, and then launch the instance from the copied AMI without needing to recreate the volume from individual snapshots or reconfigure instance metadata.

Answer

Share the AMI with the target region.

Answer

Use EBS snapshots directly in the DR region.

Answer

Configure AWS Backup to copy backups to the DR region.

Question 13

A company uses AWS CloudTrail to log API activity. The SysOps administrator needs to ensure that log files are protected from accidental deletion and are available for compliance audits for at least 7 years. Which service should be used to meet these requirements?

Accepted Answer

Enable S3 Object Lock in Compliance mode.. S3 Object Lock in Compliance mode provides a write-once-read-many (WORM) model that prevents any user, including the AWS account root user, from deleting or overwriting objects for the specified retention period. This meets both the protection from accidental deletion and the 7-year compliance audit requirement, as the retention mode cannot be shortened or removed once applied.

Answer

Enable S3 Versioning on the CloudTrail S3 bucket.

Answer

Move CloudTrail logs to Amazon S3 Glacier after 90 days.

Answer

Store logs in Amazon CloudWatch Logs with an expiration policy of 7 years.

Question 14

An application running on Amazon ECS with Fargate launch type is experiencing intermittent failures. The tasks are spread across multiple Availability Zones. The SysOps administrator notices that failures occur only when an entire AZ becomes unavailable. What should the administrator do to improve the reliability of the application?

Accepted Answer

Increase the desired task count to ensure sufficient capacity across AZs.. Increasing the desired task count ensures that ECS Fargate tasks are distributed across multiple Availability Zones, providing sufficient capacity to absorb the loss of an entire AZ. When one AZ becomes unavailable, the remaining tasks in other AZs continue to serve traffic, improving application reliability. This approach leverages the multi-AZ architecture already in place by ensuring enough tasks are running to handle the load even after an AZ failure.

Answer

Use multiple subnets in the same AZ.

Answer

Use a cluster placement group.

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Attach an Amazon EFS filesystem to all tasks.

Question 15

A company uses Amazon Route 53 for DNS and has a domain registered with Route 53. The company wants to ensure that if the primary web server fails, traffic is automatically routed to a secondary server in a different region. The health check must consider both the server response and the application response time. Which routing policy should be used?

Accepted Answer

Failover routing policy. Failover routing policy is correct because it allows you to configure an active-passive setup where Route 53 automatically routes traffic to a secondary resource when the primary fails. By associating a health check that monitors both server response (HTTP status code) and application response time (latency threshold), Route 53 can detect failure and trigger the failover. This policy directly supports the requirement for automatic failover based on a composite health check.

Answer

Weighted routing policy

Answer

Geolocation routing policy

Answer

Latency routing policy