Exam AWS Certified Solutions Architect - Associate SAA-C03 topic 1 question 955 discussion

RTO 30 minute, warm standby.

https://docs.aws.amazon.com/whitepapers/latest/disaster-recovery-workloads-on-aws/disaster-recovery-options-in-the-cloud.html The DR solution does not need to support customer usage when the primary infrastructure is healthy. -> Pilot Light

I would have gone with answer A if it were not for this one item - The acceptable recovery time for the DR solution is up to 30 minutes. That would be ideal for pilot light, which would be within the 30 minute window. AI - The recovery time objective (RTO) for an AWS Pilot Light disaster recovery strategy typically ranges from minutes to tens of minutes.

A is not right because the max and min are set to minimum which is zero. and the global table use resource.

The question doesn't ask about the most cost effective solution. A is the option that ensures the lowest recovery time

Well just a thought, I hate it when each option looks like a valid one... I think I'll go with A because it seems to me other options are somewhat flawed compared to A. B - "The DR solution does not need to support customer usage when the primary infrastructure is healthy." So active-active failover is not necessary. C - Restoring a database from AWS Backup can take hours to complete, let alone the 30-minute RTO. If I remember it correcly, it can take up to 7 days? D - Just like C. One more thing about option D, the desired capacity parameter in an Auto Scaling group determines the number of EC2 instances that should be running. By setting it to 0, the group will not launch any EC2 instances during normal operations, so costs are reduced when idle. That's a plus actually.

The correct answer is A. Explanation: Option A: Correct. This solution sets up disaster recovery infrastructure in a secondary region with minimal running costs by keeping the Auto Scaling group's desired and maximum capacity low. By converting the Aurora MySQL DB cluster to an Aurora global database, the company can provide rapid cross-region replication and promote the standby database to primary if needed, minimizing downtime. Configuring active-passive failover using Route 53 ensures the DR system is only activated when necessary, aligning with the requirement of not supporting customer usage when the primary infrastructure is healthy.

RTO 30 min has to be warm standby. AWS Backup DOES NOT back up configuration, it backs up DATA

pilot light, set auto scaling group desired capacity to 0

Restoring Database from AWS back up could take from a few min to several hours. So not D

I will choose Option A for the following options: #1 - Active-passive failover: This aligns with the requirement of a DR solution that doesn't need to support customer usage during normal operations, meaning the secondary region only activates when a primary failure occurs. # 2 - Minimal Auto Scaling group capacity: Setting the desired and maximum capacity to a minimum value ensures minimal cost when the DR infrastructure is not actively used. # 3 - Aurora Global Database: Converting the Aurora cluster to a global database allows for fast failover to the secondary region, meeting the 30-minute recovery time objective. #4 - Separate AWS Region: Deploying the DR infrastructure in a different region provides geographic redundancy, crucial for disaster recovery.

D is pilot-light because desired min capacity =0 so ressources are live , services idle, RTO 10s.Ressources are provisionned and scale after even.

It can be A, if minimum value = 0. It Can be D, if this approach is implemented before the disaster. And "Set the Auto Scaling group desired capacity to zero" means that it supposed to be done before the disaster.