How does Wasabi handle multipart uploads?
Wasabi supports the AWS S3 API multipart upload capability that allows you to essentially 'chunk' a large file into separate parts that are automatically put back together as a single file when the file transmission is done. The benefit of this approach is that a large file can be uploaded more efficiently and in the event of a file transmission failure, the storage app can resume uploading with the part that failed (vs. starting at the beginning).
This AWS document provides a good explanation of how multipart upload works in the S3 API. Wasabi adheres to the approach described in this document with the following exception:
Wasabi does not currently support the AbortIncompleteMultipartUpload lifecycle action that allows you to configure a lifecycle policy that will delete aborted multipart(s) after a specified period of time. Instead, Wasabi uses a fixed value of 30 days. This means that after 30 days, any aborted multiparts are automatically deleted by Wasabi. Wasabi plans to support the AbortIncompleteMultipartUpload lifecycle action in a future release.
Aborted multiparts occur when a multipart upload begins but is not completed due to a planned (the sending app intentionally stops the multipart upload) or unplanned (the transmission of the part is unexpectedly interrupted). Wasabi, just like AWS, currently bills for the storage associated with uncommitted multiparts (aborted or abandoned) as long as they are kept in the system as active storage which is currently 30 days.
In summary, an incomplete multipart object is charged as "active" storage for the first 30 days from creating time, and then it will be considered as "deleted" storage based on "Retention" days on the billing plan.
For example:
- If a customer has 30 days minimum retention plan, then uncommitted multipart(s) are only charged for active storage for 30 days and after that, they are not charged for deleted storage.
- If a customer has 90 days minimum retention plan, then uncommitted multipart(s) are charged for active storage for 30 days and after that, they are charged for deleted storage for the next 60 days.