Comment by mlyle

Comment by mlyle 10 months ago

1 reply

No. An element of a distributed system that wants to debit from bank accounts must acknowledge the receipt of a message after making its effects durable. That system may fail between the change being durable and the acknowledgment making it back to the original sender.

That element must tolerate that debit being delivered multiple times. And we can't even solve that problem by a higher-order system providing "reliable delivery" on that element, unless that thing persists atomically with the application performing the transaction (or the application itself tolerates multiple delivery).

lisper 10 months ago

> An element of a distributed system that wants to debit from bank accounts must acknowledge the receipt of a message after making its effects durable.

I do not and never have disputed that. But I fail to see what that has to do with the matter at hand, namely, whether or not exactly-once delivery is possible.