Stalled transfer

How it works

The socket can stay open. A stall detector watches bytes over time and kills the attempt so retry can run. Without it, a job sits at 40 percent until a human notices in the morning.

An SFTP put stays at 1.2 GB of 4 GB for 20 minutes. The stall rule kills it at 5 minutes of zero bytes and retries. The second attempt finishes. The unwatched job would have held the window all night.

How it differs

A stall is not a throttle. A throttle still moves bytes, slowly.

Killing a stall that is only a slow disk wastes a good transfer.

Set the idle window from real rates.

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 stalled transfer, 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 stalled transfer 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.