You are working for an organization which is actively using AWS. They have noticed that few AWS ECS clusters are running and they do not know who and when the clusters are created. They tasked you to find out the logs regarding this. What will you do?

Answer options:

A.Check CloudWatch event logs.
B.Check CloudTrail logs.
C.Check CloudWatch metrics dashboard.
D.Check Trusted Advisor.

Answer: B
Amazon ECS is integrated with AWS CloudTrail, a service that provides a record of actions taken by a user, role, or an AWS service in Amazon ECS. CloudTrail captures all API calls for Amazon ECS as events, including calls from the Amazon ECS console and from code calls to the Amazon ECS APIs.
https://docs.aws.amazon.com/AmazonECS/latest/developerguide/logging-using-cloudtrail.html#understanding-service-name-entries
Options A and C are for monitoring the ECS resources, not for the API actions made on ECS. You can monitor your Amazon ECS resources using Amazon CloudWatch, which collects and processes raw data from Amazon ECS into readable, near real-time metrics.