> Ok so maybe the letter gets sent more than once but the message gets sent exactly once, because the messages are numbered and you only process each number once.
Isn't that just shifting the goal a bit? Now the trick is "only process each number once" which seems to have its own transactional issues if you can crash between "taking action based on the message" and "recording that this number has been seen"? If you need non-idempotent actions wouldn't this still be a potential issue?
Isn't that just shifting the goal a bit? Now the trick is "only process each number once" which seems to have its own transactional issues if you can crash between "taking action based on the message" and "recording that this number has been seen"? If you need non-idempotent actions wouldn't this still be a potential issue?