Implementing Data Consistency Option for Real-time Scores in DynamoDB | AWS Certified Cloud Practitioner Exam

Correct Answer - A.

Since the gamers are from geographically distinct locations, the data will need to be immediately readable within a second as soon as it is written.

Therefore strongly consistency is needed.

https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/HowItWorks.ReadConsistency.html

Option B is INCORRECT because the scenarios outline that the participants of the game are live.

It will not suffice if any of them get updates on scores in less than real-time.

Option C is INCORRECT because strong eventual consistency is not applicable in DynamoDB.Option D is INCORRECT because only two data consistency models are available with the DynamoDB service.

Optimistic consistency is not supported.

In this scenario, we have a live online game that uses DynamoDB instances to store real-time scores of participants. DynamoDB is a NoSQL database that offers multiple data consistency options. The choice of data consistency option depends on the specific use case.

A. Strongly Consistent: If we choose the strongly consistent option, then every read operation will return the most up-to-date data. It means that DynamoDB will always respond with the latest data, and the reads are not allowed until all previous writes have been completed. This option ensures that the data is consistent across all regions and accounts, but it can cause higher latency.

B. Eventually Consistent: If we choose the eventually consistent option, then the reads might not reflect the most up-to-date write, but they will eventually converge to a consistent state. It means that the data will be consistent, but it can take some time to propagate across all regions and accounts. This option can improve performance and reduce latency, but it can also cause some inconsistency for a short time.

C. Strong Eventual Consistency: Strong eventual consistency is a blend of both strongly consistent and eventually consistent options. It guarantees that all replicas will be eventually consistent, but also ensures that the reads are not allowed until all previous writes have been completed. This option is suitable for applications that require high consistency but can tolerate some additional latency.

D. Optimistic Consistency: Optimistic consistency is a weaker form of consistency that assumes that conflicts are rare, and if they do occur, the application will resolve them. In this option, the database doesn't perform any consistency checks, but the application is responsible for resolving any conflicts. This option can provide better performance, but it can also increase the complexity of the application.

Based on the use case of a live online game, where real-time scores are updated frequently, it is important to have the most up-to-date data available to all participants. Therefore, the strongly consistent option is the most appropriate to implement, as it ensures that every read operation returns the most up-to-date data, which is critical for the participants to see their scores in real-time. However, this option can cause higher latency, which might affect the overall performance of the game. Therefore, it is important to monitor the latency and optimize the performance of the application accordingly.