Using Electrum RBF, I attempted to increase a transaction fee (by an arbitrary amount) to learn the process.
This fee that Electrum selects ( 1.5sat/byte over the previous 1sat/byte) appears to be fine for my learning (I'm happy to wait or have it fall from the mempool eventually).
But when trying to broadcast the transaction the following comes up:
I am using my own node so it wasn't the server. So I was trying to think why this would be. I tried a variety of different unconfirmed transactions before trying one at 2 sat/byte. Which worked.
Was the error in actual fact just trying to increase the fee by too small an amount?
If so, I believe changing the error message to reflect this (or a message suggesting minimum increase/multiple) would be helpful.
Edit - Reading through BIP125 I see the following which probably explains why my transaction required a higher fee-bump:
4. The replacement transaction must also pay for its own bandwidth at or above the rate set by the node's minimum relay fee setting. For example, if the minimum relay fee is 1 satoshi/byte and the replacement transaction is 500 bytes total, then the replacement must pay a fee at least 500 satoshis higher than the sum of the originals.
Maybe the suggested minimum RBF fee suggested/allowed by Electrum could reflect this rule (if that is indeed the current network rule).
So my 316 byte transaction required a fee bump of at least 316 bytes to be accepted by (most) of the network). <- Maybe an explanation of this requirement could be included in the error message?
