Question 312 - SCS-C02 discussion

The correct answer is A. Configure an S3 Lifecycle rule on the S3 bucket to delete objects after 45 days.

The reason is that this is the simplest and most effective way to enforce the data retention policy. According to the AWS documentation1, ''To manage your objects so that they are stored cost effectively throughout their lifecycle, configure their Amazon S3 Lifecycle. An S3 Lifecycle configuration is a set of rules that define actions that Amazon S3 applies to a group of objects. There are two types of actions: Transition actions and Expiration actions.'' The documentation1 also states that ''Expiration actions define when objects expire. Amazon S3 deletes expired objects on your behalf.'' Therefore, by configuring an S3 Lifecycle rule on the S3 bucket to delete objects after 45 days, the security engineer can ensure that the data is removed from the S3 bucket according to the company's policy.

The other options are incorrect because:

B) Create an AWS Lambda function to check the last-modified date of the S3 objects and delete objects that are older than 45 days. Create an S3 event notification to invoke the Lambda function for each PutObject operation. This option is not optimal because it requires deploying and maintaining a Lambda function, which adds complexity and cost. Moreover, it does not guarantee that the data is deleted exactly after 45 days, since the Lambda function is triggered only when a new object is put into the S3 bucket. If there are no new objects for a long period of time, the Lambda function will not run and the data will not be deleted.

C) Create an AWS Lambda function to check the last-modified date of the S3 objects and delete objects that are older than 45 days. Create an Amazon EventBridge rule to invoke the Lambda function each month. This option is not optimal because it requires deploying and maintaining a Lambda function, which adds complexity and cost. Moreover, it does not guarantee that the data is deleted exactly after 45 days, since the Lambda function is triggered only once a month. If the data is older than 45 days but less than a month, it will not be deleted until the next month.

D) Configure S3 Intelligent-Tiering on the S3 bucket to automatically transition objects to another storage class. This option is not sufficient to enforce the data retention policy, because it does not delete the data from the S3 bucket. It only moves the data to a less expensive storage class based on access patterns. According to the AWS documentation2, ''S3 Intelligent-Tiering optimizes storage costs by automatically moving data between two access tiers, frequent access and infrequent access, when access patterns change.'' However, this feature does not expire or delete the data after a certain period of time.