A data science bucket holds 60 TB of large files. Some are read every day for a month and then never again; others are read at unpredictable intervals for years. Nobody can say in advance which is which, and the team does not want to own and maintain a set of lifecycle rules. Which storage class fits?
AWS Certified Cloud Practitioner (CLF-C02), objective 3. Cloud technology and services medium
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The options
Correct S3 Intelligent-Tiering
Correct. It watches the access pattern of each object and moves it between access tiers automatically, so unpredictability stops being a problem you have to model. It charges a small monitoring and automation fee per object and no retrieval fee for its frequent and infrequent access tiers.
Not correct S3 Standard, with a lifecycle rule moving objects to Standard-IA after 30 days
Wrong twice over. It is exactly the rule the team said it does not want to maintain, and a fixed age is the wrong signal here: an object still being read daily would be demoted on its birthday and then charged a retrieval fee for every read after that.
Not correct S3 One Zone-Infrequent Access for everything
Wrong. It is cheaper per gigabyte because it keeps the data in a single Availability Zone, which is a poor bet for research data that cannot be regenerated, and it is the wrong tier for objects that turn out to be read daily.
Not correct S3 Glacier Flexible Retrieval
Wrong. Some of this data is read daily. An archive class would mean waiting minutes to hours for those reads and paying a retrieval charge each time.
Why
Intelligent-Tiering is the answer to 'we do not know the access pattern', and knowing when it is the wrong answer is what makes it a real choice rather than a default: it charges per object for monitoring, so a bucket of many millions of very small objects can spend more on monitoring than it saves on tiering. Lifecycle rules remain the right tool when the pattern IS known — logs that are useless after ninety days, for instance.
Where this comes from
- Cited
- AWS exam guide task statement 3.6
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