Exam AWS Certified Solutions Architect - Associate SAA-C03 topic 1 question 391 discussion

that if there is no temporary local storage on the EC2 instances, then snapshots of EBS volumes are not necessary. Therefore, if your application does not require temporary storage on EC2 instances, using AMIs to back up the web and application tiers is sufficient to restore the system after a failure. Snapshots of EBS volumes would be necessary if you want to back up the entire EC2 instance, including any applications and temporary data stored on the EBS volumes attached to the instances. When you take a snapshot of an EBS volume, it backs up the entire contents of that volume. This ensures that you can restore the entire EC2 instance to a specific point in time more quickly. However, if there is no temporary data stored on the EBS volumes, then snapshots of EBS volumes are not necessary.

The web application does not require temporary local storage on the EC2 instances => No EBS snapshot is required, retaining the latest AMI is enough.

The web application does not require temporary local storage on the EC2 instances so we do not care about ECS. We only need two things here , the image of the instance (AMI) and a database backup. C

"The web application does not require temporary local storage on the EC2 instances" rules out any option to back up the EC2 EBS volumes.

Question says: ...stateless web application.. that means application doesn't store any data, so no EBS required

Since the application has no local data on instances, AMIs alone can meet the RPO by restoring instances from the most recent AMI backup. When combined with automated RDS backups for the database, this provides a complete backup solution for this environment. The other options involving EBS snapshots would be unnecessary given the stateless nature of the instances. AMIs provide all the backup needed for the app tier. This uses native, automated AWS backup features that require minimal ongoing management: - AMI automated backups provide point-in-time recovery for the stateless app tier. - RDS automated backups provide point-in-time recovery for the database.

BBBBBBBBBB

I vote for D

makes more sense.

Answer is C. Keyword to notice "Stateless"

why B? I mean "stateless" and "does not require temporary local storage" have indicate that we don't need to take snapshot for ec2 volume.

Option B is the most appropriate solution for the given requirements. With this solution, a snapshot lifecycle policy can be created to take Amazon Elastic Block Store (Amazon EBS) snapshots periodically, which will ensure that EC2 instances can be restored in the event of an outage. Additionally, automated backups can be enabled in Amazon RDS for PostgreSQL to take frequent backups of the database tier. This will help to minimize the RPO to 2 hours. Taking snapshots of Amazon EBS volumes of the EC2 instances and database every 2 hours (Option A) may not be cost-effective and efficient, as this approach would require taking regular backups of all the instances and volumes, regardless of whether any changes have occurred or not. Retaining the latest Amazon Machine Images (AMIs) of the web and application tiers (Option C) would provide only an image backup and not a data backup, which is required for the database tier. Taking snapshots of Amazon EBS volumes of the EC2 instances every 2 hours and enabling automated backups in Amazon RDS and using point-in-time recovery (Option D) would result in higher costs and may not be necessary to meet the RPO requirement of 2 hours.

B. Configure a snapshot lifecycle policy to take Amazon Elastic Block Store (Amazon EBS) snapshots. Enable automated backups in Amazon RDS to meet the RPO. The best solution is to configure a snapshot lifecycle policy to take Amazon Elastic Block Store (Amazon EBS) snapshots, and enable automated backups in Amazon RDS to meet the RPO. An RPO of 2 hours means that the company needs to ensure that the backup is taken every 2 hours to minimize data loss in case of a disaster. Using a snapshot lifecycle policy to take Amazon EBS snapshots will ensure that the web and application tier can be restored quickly and efficiently in case of a disaster. Additionally, enabling automated backups in Amazon RDS will ensure that the database tier can be restored quickly and efficiently in case of a disaster. This solution maximizes scalability and optimizes resource utilization because it uses automated backup solutions built into AWS.