Identifying Blocked Queries

Answer: D.

Option A is incorrect because CloudWatch Logs does not contain details of queries that are currently executing on a DocumentDB cluster.

Option B is incorrect because AWS X-Ray is used for debugging and tracing requests in microservices applications.

Option C is incorrect because CloudTrail is a log of AWS services API activity.

It cannot be used for monitoring and analyzing the performance of DocumentDB databases.

Option D is CORRECT because MongoDB currentOp command can be used to list queries that are either blocked or executing longer than a specified time.

Reference:

https://docs.aws.amazon.com/documentdb/latest/developerguide/user_diagnostics.html#user_diagnostics-query_terminating

A database specialist can use the MongoDB currentOp command to identify blocked queries on a DocumentDB cluster. DocumentDB is a managed database service that is compatible with MongoDB, which means that it uses the MongoDB API, drivers, and tools. The currentOp command is a MongoDB command that returns information about the current operations that are running on a MongoDB instance.

To use the currentOp command on a DocumentDB cluster, the database specialist can connect to the cluster using the mongo shell or a MongoDB client. Then, they can run the currentOp command to see information about the current operations, including any blocked queries.

CloudWatch Logs, AWS X-Ray, and CloudTrail Events are all monitoring and logging services provided by AWS, but they are not specifically designed to identify blocked queries on a DocumentDB cluster. CloudWatch Logs is a service that allows you to monitor, store, and access log files from AWS resources. AWS X-Ray is a service that helps you analyze and debug distributed applications. CloudTrail is a service that records API activity and events for AWS services.

Therefore, option D, the MongoDB currentOp command, is the correct answer for identifying blocked queries on a DocumentDB cluster.