Hot folder

How it works

The trigger must wait until the file is finished. Size-stable checks or a rename into the folder prevent a pickup of a partial. A hot folder is automation with a filesystem interface.

An exporter writes export.tmp and renames to export.csv. The watcher fires on the rename and sends 200 MB. A watcher that fired on create sent a 0-byte file last month.

How it differs

A hot folder is not a queue with retries unless you add those. A crash after pickup can lose the trigger.

Two watchers on one folder double-send.

One consumer, or a lock.

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 hot folder, 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 hot folder 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.