Cost optimization bw RDS

[Vu Hoang Nam]

“A company uses computer simulations for modeling weather patterns in a certain country. The simulations generate terabytes of data, which is stored in a MySQL 5.6 database that runs in an Amazon EC2 instance. A Ruby on Rails application is hosted on a separate EC2 instance to process the data. The current database size is 16 TB and is expected to grow as more complex simulations are created continuously. The facility wants to re-architect its infrastructure to be highly scalable and highly available as they need to run the application reliably 24×7.

Which of the following is the MOST cost-effective solution that can satisfy the above requirements?”

>>> For database, there are two options.

– Migrate the MySQL database to Amazon Aurora. Create a read-replica on another Availability Zone of the Aurora instance for high availability.

– Migrate the MySQL database to an Amazon RDS MySQL instance with Multi-AZ enabled. Adjust the RDS Storage volume manually as demand increases.

And the correct response was using Aurora.

I think RDS MySQL would be cheaper than Aurora, and although volume capacity is adjusted manually, but it can still be possible?

[Kenneth-Samonte-Tutorials-Dojo]

Hi Vu Hoang Nam,

Thanks for your feedback on this question.

I understand that RDS MySQL is a more cost-effective solution. However, in the exam, there is a difference between the cost-effectiveness and the recommended solution that is cost-effective (from AWS perspective).

Think of it this way, if you just want the cheapest solution, then using EC2 instances with MySQL installed is cheaper compared to an RDS instance. However, you will never see an answer on the exam to choose EC2 with MySQL because AWS does not want you to do manual work.

The questions on the exam are focused on choosing the right service (as per AWS) with the least amount for manual work. If one of the choices has the word “manually” on it, even if it is the cheapest option, it probably isn’t the correct option.

Here, cost-effective means choosing the AWS service that is least expensive while still maintaining the flexibility and automatic elastic scaling that AWS offers. Therefore, we should choose AWS Aurora in this question.

Hope this helps.

Let us know if you need further assistance. The Tutorials Dojo team is dedicated to helping you pass your AWS exam!

Regards,

Kenneth Samonte @ Tutorials Dojo