The S3 API doesn't have the concurrency control primitives necessary to guarantee consistency in the face of concurrent writes.
I wrote a distributed lock on Google Cloud Storage. https://www.joyfulbikeshedding.com/blog/2021-05-19-robust-di...
During my research it was quickly evident that GCS has more concurrency control primitives than S3. Heck S3 didn't even guarantee strong read-after-write until recently.
While I'm sure you're right, this VFS implementation doesn't use any of that stuff. They just handwave concurrent writes away by saying the application has to ensure a single writer on its own. An S3 implementation appears to be planned; it's mentioned in the comments in the bcvmodule.c file.
Ah, I'm guessing that's the same reason why many "cloud storage as a backend" stuff (e.g. Terraform/Vault storage backends, Delta.io backends) require DynamodDB + S3
I wrote a distributed lock on Google Cloud Storage. https://www.joyfulbikeshedding.com/blog/2021-05-19-robust-di... During my research it was quickly evident that GCS has more concurrency control primitives than S3. Heck S3 didn't even guarantee strong read-after-write until recently.