Q104 — AWS SAA-C03 Ch.4

Question 104 of 105 | ← Chapter 4

Q299. A meteorological startup company has a custom web application to sell weather data to its users online. The company uses Amazon DynamoDB to store its data and wants to build a new service that sends an alert to the managers of four internal teams every time a new weather event is recorded. The company does not want this new service to affect the performance of the current application. What should a solutions architect do to meet these requirements with the LEAST amount of operational overhead?

• A. Use DynamoDB transactions to write new event data to the table Configure the transactions to notify internal teams
• B. Have the current application publish a message to four Amazon Simple Notification Service (Amazon SNS) topics Have each team subscribe to one topic
• C. Enable Amazon DynamoDB Streams on the table Use triggers to write to a single Amazon Simple Notification Service (Amazon SNS) topic to which the teams can subscribe. ✓
• D. Add a custom attribute to each record to flag new items. Write a cron job that scans the table every minute for items that are new and notifies an Amazon Simple Queue Service (Amazon SQS) queue to which the teams can subscribe

Correct Answer: C. Enable Amazon DynamoDB Streams on the table Use triggers to write to a single Amazon Simple Notification Service (Amazon SNS) topic to which the teams can subscribe.

Explanation

Amazon DynamoDB is integrated with AWS Lambda so that you can create triggers--pieces of code that automatically respond to events in DynamoDB Streams. With triggers, you can build applications that react to data modifications in DynamoDB tables.If you enable DynamoDB Streams on a table, you can associate the stream Amazon Resource Name (ARN) with an AWS Lambda function that you write. Immediately after an item in the table is modified, a new record appears in the table's stream. AWS Lambda polls the stream and invokes your Lambda function synchronously when it detects new stream records.The Lambda function can perform any actions you specify, such as sending a notification or initiating a workflow.source: https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Streams.Lambda.html