At-least-once is a storage problem
RabbitMQ can deliver a message twice. The hard part is making the second delivery boring.
C#/.NET · RabbitMQ · SQL
Engineering notes
Ideas I can test.
Short arguments about systems software. Start with the claim, inspect the mechanism, and stop where the evidence stops.
Archive
Newest first.
A replay is only useful when it leaves evidence
Random failure looks realistic. Deterministic failure can be reviewed.
xUnit · RabbitMQ · CI · PowerShell
The system is the path, not the executable
A command still has to survive queues, translation, transport, a device, and the return path.
Control paths · Interfaces · Verification