Does S3 Console Upload Use Multipart?

Question

I just cancelled a 140GB single object upload due to slow transfer speeds, then the console suggested I create a lifecycle rule to remove abandoned parts.  Does the console use multipart on the backend?  I keep trying to show any orphaned parts, but you need an upload ID, which I don't have.  Is it safe to assume there are no parts remaining or is there another way to check?  Thanks!

Riku_Kobayashi · Accepted Answer

Hello.

Yes, also use multipart uploads when uploading from the management console.  
https://docs.aws.amazon.com/AmazonS3/latest/userguide/checking-object-integrity.html#large-object-checksums  
> When objects are uploaded to Amazon S3, they can either be uploaded as a single object or through the multipart upload process. Objects that are larger than 16 MB and uploaded through the console are automatically uploaded using multipart uploads. For more information about multipart uploads, see Uploading and copying objects using multipart upload.

You can use the AWS CLI command described in the document below to check whether partial files remain after multipart upload fails.  
https://repost.aws/knowledge-center/s3-multipart-upload-cli  
```
aws s3api list-multipart-uploads --bucket DOC-EXAMPLE-BUCKET
```

Matt-B · Answer

Hi There

Yes, uploading an object in the Console uses multi-part upload.  See https://docs.aws.amazon.com/AmazonS3/latest/userguide/mpu-upload-object.html

You can also see this in action.  Try uploading a larger object (> 100MB) and open your browser's development console.  In the networking tab, you will see PUT requests being initiated for each part.  You can see `partNumber` as a header in each request.  You can also see the `uploadId` as well.

Does S3 Console Upload Use Multipart?

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