Exams / SAA-C03 / S3 upload and transfer performance / Question 1
SAA-C03 practice question: S3 upload and transfer performance (1 of 2)
Design High-Performing Architectures A free question from our original SAA-C03 practice exam. Try it, then open the answer to see why each option is right or wrong.
A video production company uploads finished films of 2 GB to 20 GB from its studio to an Amazon S3 bucket using single PUT requests. Over the studio's unreliable connection, uploads often fail part-way and must restart from the beginning, and the largest films are always rejected. A developer has been testing multipart uploads with a script, and a billing review now shows the bucket is charged for storage that does not appear as any object. Which solution addresses all of these problems?
Choose one answer.
- AA. Turn on S3 Transfer Acceleration and keep the single PUT requests, with a lifecycle rule that aborts incomplete multipart uploads after 7 days.
- BB. Use multipart uploads with 100 MB parts, retrying only failed parts, and a lifecycle rule that aborts incomplete multipart uploads after 7 days.
- CC. Use multipart uploads with 100 MB parts, retrying only failed parts, and a lifecycle rule that expires noncurrent object versions after 7 days.
- DD. Use multipart uploads with 100 MB parts uploaded in parallel, and turn on S3 Versioning so that interrupted uploads can resume from earlier versions.
Show the answer and explanation
Answer: B
- A. Wrong: Transfer Acceleration can speed up long-distance uploads, and the lifecycle rule would clean up the abandoned parts. However, a single PUT is limited to 5 GB, so the largest films would still be rejected, and a failed upload would still restart from the beginning. Learn more: Configuring fast, secure file transfers using Amazon S3 Transfer Acceleration (opens in a new tab)
- B. Right: Correct. Multipart upload is required for objects over 5 GB and lets the client retry only the parts that fail, instead of the whole file. Parts of uploads that were never completed are billed as storage until the upload is stopped, and the AbortIncompleteMultipartUpload lifecycle action removes them automatically. Learn more: Uploading and copying objects using multipart upload in Amazon S3 (opens in a new tab)
- C. Wrong: Multipart upload fixes the size limit and the restarts. However, noncurrent version expiration only removes old versions of completed objects; it does not touch the parts of incomplete multipart uploads, so the unexplained storage charge remains. Learn more: Managing the lifecycle of objects (opens in a new tab)
- D. Wrong: Multipart upload fixes the size limit, but versioning keeps versions of completed objects only. It does nothing for incomplete uploads, so the abandoned parts would keep being billed. A lifecycle rule that aborts incomplete multipart uploads is needed. Learn more: How S3 Versioning works (opens in a new tab)
Explanation
Three problems point to the answer: files over 5 GB cannot be sent in one PUT, failed uploads restart from scratch, and abandoned multipart parts are billed. Multipart upload solves the first two because parts are retried individually, and an AbortIncompleteMultipartUpload lifecycle rule removes leftover parts. Noncurrent version rules and versioning only affect completed objects.
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