Technically, expedited retrieval for files is not guaranteed within 1-5 minutes for files larger than 250 MB+. See https://docs.aws.amazon.com/AmazonS3/latest/userguide/restoring-objects-retrieval-options.html.

S3 Standard-IA is for data that is accessed less frequently, but requires rapid access when needed. S3 Standard-IA offers the high durability, high throughput, and low latency of S3 Standard, with a low per GB storage price and per GB retrieval chargehttps://aws.amazon.com/s3/storage-classes/

"Expedited Retrieval, you can retrieve small amounts of data (up to 250 MB per request) within 1-5 minutes." Cannot C

(A) is eliminated. Demand metric is popularly based & cannot be configured with Lifecycle policies. Ex: an old movie can have resurgent demand 20 years after it's sequel is released. (C) is eliminated. Expedited retrieval is for all but the largest archived objects (250 MB+). (D) is eliminated. Bulk retrieval takes hours. (B) is more expensive than S3 Glacier Flexible Retrieval but it's the only one that works.

Option B makes the most sense. Why not option C: 1. This is not an archival use case, the company runs a video streaming service, so objects are still accessed regularly. Accelerated Retrieval is designed for "occasional urgent requests for a subset of archives". 2. The 5 minute timeframe does not apply to items of 250+ MB. 3. Even if the timeframe were valid, it's not guaranteed ("typically") 4. Expedited retrieval is expensive if used frequently ($10.00 per 1,000 requests) - depending on access patterns, this may more than offset the savings in storage costs. https://docs.aws.amazon.com/AmazonS3/latest/userguide/restoring-objects-retrieval-options.html

All old files should be in--> Glacier Flexible Retrieval takes (1-5 minutes) to retrieve the file. New files should not stay in Standard Storage class forever --> Intelligent-Tiering

More insight: S3 Glacier Flexible Retrieval for the most flexible retrieval options that balance cost with access times ranging from minutes to hours. Your retrieval options permit you to access all the archives you need, when you need them, for one low storage price. This storage class comes with multiple retrieval options: - Expedited retrievals (restore in 1–5 minutes) - Standard retrievals (restore in 3–5 hours) - Bulk retrievals (restore in 5–12 hours). Bulk retrievals are available at no additional charge

A - Cost optimization for > 20-yr-old files is insufficient. B - Good. Although, S3 Standard-IA is still relatively expensive compared to archival classes. C - Glacier Flexible Retrieval may not consistently meet the 5-minute streaming requirement. Could be minutes, could be hours. D - Bulk retrieval typically takes hours, let alone 5 minutes.

I don't think C is an option, S3 Glacier Flexible takes hour to retrieve the data. Option A is actually valid, but the way the option A describe it does not consider "demand patterns based on time" So it should be B

There is something I like about option A. It's the only one that deals with what happens with a movie that goes from "new" to "old". With other options, new movies will be new forever.

A is most correct ✅

Expedited 1-5min and for new files intelligent tier is a good option

It is B because: - An AWS Glacier is used for archival purposes, which is not our case. - We have a known pattern, so there are no reason to use inteligent tearing

S3 Standard-infrequent Access (S3 Standard-IA) do not come with retrieval options?? https://docs.aws.amazon.com/AmazonS3/latest/userguide/restoring-objects-retrieval-options.html

expedited retrieval should not be used in that way as well

this is the reason we choose C as answer! S3 Glacier Flexible Retrieval has option with 5 minutes time called expedited retrieval. S3 Standard-IA do not come with option to retrieve data.... please check ..... https://aws.amazon.com/s3/storage-classes/glacier/

S3 Glacier Flexible Retrieval cannot grant the retrieval within 5 minutes even with expedited retrieval. Intellgent-Tiering is for unknow pattern, however, we already know higher demand for movies that are less than 20 years old than for movies that are more than 20 years old.

C is the correct answer.

AS the pattern is uncertain- Customer could not, in advance, segregate data, the pattern will be determined on the fly - and with regard of the following S3 feature: S3 Intelligent-Tiering is an additional storage class that provides flexibility for data with unknown or changing access patterns. It automates the movement of your objects between storage classes to optimize cost. C will be the most cost effective for this use case.

Glacier flex expedited retrieval takes 1-5 min.