Replication

How it works

Replication is a server-side transfer. It has lag. A GET in the second region can miss an object that just landed in the first. Residency rules break if the destination region is wrong. Delete replication is a separate switch.

A 9 GB master lands in region A. Replication to region B finishes four minutes later. A render in B started at minute one and reports the file missing. Waiting on the replication event fixes the race.

How it differs

Replication is not a CDN. A CDN caches HTTP responses. Replication copies objects.

A replica in the wrong country is a residency finding.

Name the destination region in the rule.

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 replication, 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 replication 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.