Synchronous link vs outbox
A synchronous write makes the chat wait for the archive on Earth, 1.28 s away one way. An outbox saves the message in a local durable queue, answers at once and sends it later. With the synchronous link, p99 is 7,360 ms. With the outbox, p99 is 71 ms and every message reaches the archive.
Lasers in orbit, New York to London · 7,151 km · 24 ms one way
4 workers · 3 jobs waiting · wait 33 ms
Case 1
The Moon base chat gets 5 messages/s for 20 s. Each must be answered within 300 ms and reach the archive on Earth within 30 s. No message may be lost.
| Measure | Goal | Chat waits for Earth | Local outbox, then relay |
|---|---|---|---|
| p99 latency | under 300 ms | 7.4 s Fail | 71 ms Pass |
| Lost writes | none | 0 Pass | 0 Pass |
| Completion time | under 30 s | 0 s Pass | 23.32 s Pass |
| Monthly cost | 28 USD/mo | 24 USD/mo | |
| Error rate | 0.2% | 0% | |
| Level rules | none broken | Board is not complete Fail | Pass |