DOP-C02 Question 154
Select 2You are managing a stateful application deployed on Amazon EC2 instances. The application stores critical data on instance volumes and requires minimal downtime during failover. Which of the following configurations would best ensure data replication and allow seamless failover in case of instance failure?
- A
Use Amazon EBS volumes with Multi-Attach enabled and attach the volume to multiple EC2 instances in the same Availability Zone.
- B
Implement Amazon EC2 Auto Scaling with a health check policy and use Amazon Elastic File System (EFS) for shared storage.
- C
Configure Amazon RDS Multi-AZ deployments to handle failover for the application data.
- D
Use Amazon S3 for data storage and configure the application to retrieve data from S3 upon failover.
- E
Leverage AWS Elastic Disaster Recovery (AWS DRS) to replicate the EC2 instance and its associated storage.
Show answer and explanation
Correct answers: B, E
Explanation
For a stateful application, failover requires both data replication and recovery mechanisms. Option 2 (EC2 Auto Scaling with EFS) ensures high availability through Auto Scaling for failover and EFS for shared, persistent storage, making it ideal for stateful services. Option 5 (AWS Elastic Disaster Recovery) provides a robust disaster recovery solution that replicates the entire instance and its storage for minimal downtime during failover. These two options together meet the requirements of the scenario.
- A. Incorrect.
Amazon EBS Multi-Attach allows you to attach a single EBS volume to multiple instances, but it is not designed for stateful application data replication or seamless failover. This option does not provide the required durability or failover capabilities.
- B. Correct.
Using EC2 Auto Scaling with a health check policy ensures that unhealthy instances are replaced automatically, and Amazon EFS provides persistent, shared storage that can be accessed by multiple instances. This supports both failover and replication for stateful services.
- C. Incorrect.
Amazon RDS Multi-AZ is designed for managed database failover, not for replicating stateful application data stored on EC2 instance volumes. This option is unsuitable for this scenario.
- D. Incorrect.
Amazon S3 is an object storage service and does not provide the low-latency, block-level storage required by stateful applications. While it can store data, it is not practical for seamless failover in this scenario.
- E. Correct.
AWS Elastic Disaster Recovery (AWS DRS) replicates entire EC2 instances and their attached storage into a different Availability Zone or Region. It provides a fast recovery solution for stateful applications in case of failure.