As for RPC, whether the client is informed of success or failure has nothing to do with atomicity. The guarantee is that the transaction either happens completely or not at all, and nothing more.
Agreed, it can be very frustrating that under certain failure scenarios, it's unclear whether the transaction completed or rolled back. Still, given atomicity, a correctly designed system can't be left in an inconsistent state. At times, it's up to the application to discover (or re-discover) that state.
Systems that offer atomicity for single record operations can actually make the same assurances, but may require complicated escrow systems and compensating transactions.
As for RPC, whether the client is informed of success or failure has nothing to do with atomicity. The guarantee is that the transaction either happens completely or not at all, and nothing more.
Agreed, it can be very frustrating that under certain failure scenarios, it's unclear whether the transaction completed or rolled back. Still, given atomicity, a correctly designed system can't be left in an inconsistent state. At times, it's up to the application to discover (or re-discover) that state.
Systems that offer atomicity for single record operations can actually make the same assurances, but may require complicated escrow systems and compensating transactions.