Cost-effective / RDS vs Aurora

[Alexander Murdoch]

Hello,

The expected answer for the question below is wrong IMHO.

Why? It’s asking for the most cost-effective alternative. Both solutions provide a resilient design but Aurora is more expensive. In any case, it is a very tricky answer.

The RDS manual snapshot should not affect the performance significantly, but it would be much better than doing it on an on-premise instance.

Can you please clarify?

QUESTION:

Category: CSAA – Design Resilient Architectures

A company is running an on-premises application backed by a 1TB MySQL 8.0 database. A couple of times each month, the production data is fully copied to a staging database at the request of the analytics team. The team can’t work on the staging database until the copy is finished, which takes hours.

Throughout this period, the application experiences intermittent downtimes as well. To expedite the process for the analytics team, a solutions architect must redesign the application’s architecture in AWS. The application must also be highly resilient to disruptions.

Which combination of actions best satisfies the given set of requirements while being the most cost-effective? (Select TWO)

-Take a manual snapshot and restore it to a database in the staging environment. (my choice1)

– Use an Amazon Aurora database with Multi-AZ Replicas. (Expected answer 1)

– Clone the production database in the staging environment using Aurora cloning. (expected answer 2)

– Replicate the production database to a staging database using the mysqldump client utility.

– Use an Amazon RDS database in a Multi-AZ Deployments configuration (my answer 2)

Thanks,

Alex.

[Neil-TutorialsDojo]

Hello Alexander Mrudoch

Thank you for your inquiry regarding the AWS practice exam question. I understand your concerns about the expected answers, particularly regarding cost-effectiveness and the impact of manual snapshots. Let me address your points:

1. Cost-effectiveness of Aurora vs. RDS: While it’s true that Aurora is generally more expensive than standard RDS, the question asks for the most cost-effective solution that best meets all requirements, including expediting the process for the analytics team and ensuring high resilience. Aurora’s superior performance, especially in cloning large databases quickly, can lead to significant time and resource savings, potentially offsetting its higher upfront costs.
   See documentation here: https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/Aurora.Managing.Clone.html

2. Manual snapshots and performance: You’re correct that RDS manual snapshots should not significantly affect performance, especially compared to an on-premises solution. However, for a 1TB database, creating and restoring snapshots could still take considerable time, which doesn’t fully address the requirement to “expedite the process for the analytics team.”

3. Resilience and downtime: The question emphasizes the need for high resilience and mentions intermittent downtimes. Aurora’s architecture provides better resilience and faster failover than standard RDS Multi-AZ, which aligns more closely with the stated requirements.

4. Cloning efficiency: Aurora’s cloning feature is particularly efficient for creating staging environments quickly without impacting the production database. This directly addresses the issue of the analytics team waiting for hours.

While your choices of manual snapshots and RDS Multi-AZ are valid, the expected answers (Aurora Multi-AZ and Aurora cloning) better address all aspects of the question, including speed, resilience, and overall efficiency.

Thank you for bringing this up, as it highlights the complexity of architectural decisions in cloud environments. I hope this helps.

Best regards,

Neil @ Tutorials Dojo

[Alexander Murdoch]

Hello Neil. Very clear answer.

Yep, agree with your statements but it’s hard to balance the answer with a question stating “cost-efficient” while in most cases, when that’s mentioned, the expected answer is the cheapest one.

Anyhow, this clarifies it.

Alex.