A company wants to migrate its on-premises application to AWS. The database for the application stores structured product data and temporary user session data. The company needs to decouple the product data from the user session data. The company also needs to implement replication in another AWS Region for disaster recovery.
Which solution will meet these requirements with the HIGHEST performance?
To achieve high performance while meeting the need to decouple product data from user session data, Amazon RDS for the structured product data combined with Amazon ElastiCache for Memcached for the user session data provides a compelling solution. RDS is well-suited for structured data due to its relational model capabilities, and ElastiCache excels at managing temporary session data with high-speed access. Furthermore, configuring RDS with a read replica in another Region ensures cross-region replication and thus disaster recovery. This setup ensures high performance and fault tolerance. Although option D provides a similar setup, it does not leverage the high-performance caching that ElastiCache offers for session data. Therefore, option B better satisfies the requirements. While there are claims about global datastore in ElastiCache, it should be treated with caution, but generally, ElastiCache remains efficient for caching purposes.
C - DynamoDB is for structured, semi-structured and unstructured data. So it can also hold the product data. Indeed many e-commerce shops use DynamoDB to save the product catalogue. There is nothing in the questin that would exclude DynamoDB for the product data. C has caching with DAX so it definitely has a higher performance than D which does not have caching and even no read replica in the same region.
"C" should be wrong. "B" should be correct. "A traditional relational database management system (RDBMS) stores data in a normalized relational structure. [...] As a NON-relational database service, DynamoDB offers many advantages over traditional relational database management systems." https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/bp-relational-modeling.html
Structured Data = RDS
The database for the application stores structured product data and temporary user session data, therefore. option D
Choice is between B and D. Application information about how it is deployed in second region is missing for this question. B does not address cross region replication requirement for user sessions and assuming that is needed, option D is the right answer.
B ans https://aws.amazon.com/about-aws/whats-new/2023/04/amazon-elasticache-cache-rds-databases-console/
D is correct
The HIGHEST performance is C. Structured data does not means "SQL". Dynamodb can handle structured data with no issues.
B talks about Global Datastore for memcached while memcached doesnt support global datastore, hence B is ruled out and D is the answer.
Answer: D B also works but you will endup doing lot of custom stuff to deploy multiple ElastiCache for Memcached clusters in different Availability Zones. Pay attention to the question which says "The company also needs to implement replication in another AWS Region for disaster recovery"
I think D. ElastiCache for Memcached and DAX are good for read-heavy so they can improve performance, but not a good choice for read and write, and also Memcached – no replication
Querying structured data on DynamoDB does not provide as good performance as RDS
C - To meet Disaster Recovery requirements & get high performance with DAX
D. Structure Data so Amazon RDS and Amazon DynamoDB is well-suited for handling session data and can provide low-latency access. Not C because Dynamo is not for structured data
I did not like "Create 2 DynamoDB global tables", but as soon as the question is asking for the HIGHEST performance it's poining to DAX. C is the correct answer.
Ans B. "ElastiCache and RDS provide applications a combination of the top-tier speed of an in-memory cache with the reliability of a relational database. When provisioning an Aurora or RDS database using the RDS console, you now have the option to create and attach an associated ElastiCache cluster at the same time." https://aws.amazon.com/about-aws/whats-new/2023/04/amazon-elasticache-cache-rds-databases-console/
B - In general, SQL databases are better suited for traditional, structured data, while NoSQL databases are better suited for handling large volumes of unstructured or semi-structured data.
D is correct
C - DynamoDB with DAX is for structured data and the highest performance.