A large IT company has an on-premises website that provides real-estate information such as rent, house prices, and the latest news to users. The website has a Java backend and a NoSQL MongoDB database used to store subscribers` data. You are a cloud analyst and need to migrate the whole application to the AWS platform. Your manager requires that a similar structure should be deployed in AWS for high availability.

Answer options:

A.Deploy an Auto Scaling group of Java backend servers to provide high availability.
B.Use RDS Aurora as the database for the subscriber data because it is highly available and can scale up to 15 Read Replicas.
C.Create a DocumentDB database to hold subscriber data. Set up an Auto Scaling policy for the read/write throughput.
D.Use AWS X-Ray SDK to record data about incoming and outgoing requests. View the statistics graph in the X-Ray console.
E.Trace the requests using AWS JAVA SDK and send logs to AWS CloudWatch Events. Create a CloudWatch dashboard to view the statistics.

Correct Answer – A, C, D
As this case needs to migrate the on-premises system to AWS using a similar structure, DocumentDB is more appropriate than RDS Aurora. DocumentDB is also a NoSQL database compatible with MongoDB. Besides, AWS X-Ray is a service that collects data about requests that your application serves and provides tools you can use to view, filter, and gain insights into that data to identify issues and opportunities for optimization. Reference for AWS X-Ray is at https://docs.aws.amazon.com/xray/latest/devguide/aws-xray.html.
Option A is CORRECT because autoscaling would provide high availability.
Option Bis incorrect because RDS Aurora is a SQL database that is inappropriate in this scenario and brings extra unnecessary efforts.
Option C is CORRECT because Amazon DocumentDB is a fully managed NoSQL database service that provides fast and predictable performance with seamless scalability and compatible with MongoDB.Option D is CORRECT because AWS X-Ray is suitable to work as a tracing framework. It can monitor the requests from the frontend and requests to the DocumentDB database. Below is a graph that AWS X-Ray can provide.
Note: Please read "DynamoDB" as "DocumentDB" instead in the diagram given below. Please refer to the below link for "DocumentDB"
https://docs.aws.amazon.com/documentdb/latest/developerguide/developerguide.pdf
Option E is incorrect: Theoretically, CloudWatch can be used to trace the incoming and outgoing requests, although it may bring extra efforts. However, the service should be CloudWatch Logs rather than CloudWatch Events. Amazon CloudWatch Events describe changes in Amazon Web Services (AWS) resources.