Object versioning

How it works

A GET of the key returns the latest. A version id returns an older one. Lifecycle must expire versions or they bill forever. A transfer that overwrites a key is not a delete of yesterday's bytes if versioning is on.

A 4 GB delivery is overwritten with a fix. The client who cached the URL gets the new bytes. Audit pulls version 1 and shows what shipped first. A bucket without versioning has lost the first file.

How it differs

Versioning is not a filename with v2. V2 is a different key. Versioning is history on one key.

Delete markers hide a file that versions still store.

Expire versions on purpose.

On the ticket

• The practical close is a log line: time, actor, byte count, result.
• Without that line the transfer is a story.
• With it, the next person can see whether this door did what the ticket claimed.
• If the path is shared, say so in the partner profile so a later change does not silently pick a different limit, key, or region.
• On a real ticket, write down the door, the byte count, and the clock.
• For versioning, that means naming the host or bucket, the expected size, and the time the other side must have a complete file.
• A progress bar is not that record.
• A 200 response that arrives before the complete call is not that record.
• If a retry is allowed, say how many and whether it resumes.
• If a person must approve the send, name the person.
• Partners who receive versioning files should match on hash or size before they import.
• A same-length corrupt file passes a size check and fails a hash.
• Keep the published hash off the only channel an attacker can edit, or treat it as a corruption check rather than a substitution check.
• When the path changes, new key, new region, new cap, update the profile the same day so the next run does not use a stale limit.