RE: 90% : I think it's fine to use 90% for anything other than 1 confirmation, but if you look at the real world data test I did, or the raw data from this new code, you'll see that even the highest fee rate transactions only get confirmed at about a 90% rate in 1 block, so that if you use that as your cut-off you will sometimes get no answer and sometimes get a very high fee rate and sometimes get a reasonable fee rate, it just depends because the data is too noisy.  I think thats just because there is no good answer to that question.  There is no fee you can put on your transaction to guarantee greater than 90% chance of getting confirmed in one block.  I think 85% might be safe?

RE: tunable as command-line/bitcoin.conf: sounds good!

OK, sorry to have all this conversation on the dev list, maybe i'll turn this into an actual PR if we want to comment on the code?
I just wanted to see if it even made sense to make a PR for this or this isn't the way we wanted to go about it.




On Tue, Oct 28, 2014 at 10:58 AM, Gavin Andresen <gavinandresen@gmail.com> wrote:
On Tue, Oct 28, 2014 at 10:30 AM, Alex Morcos <morcos@gmail.com> wrote:
Do you think it would make sense to make that 90% number an argument to rpc call?  For instance there could be a default (I would use 80%) but then you could specify if you required a different certainty.  It wouldn't require any code changes and might make it easier for people to build more complicated logic on top of it.

RE: 80% versus 90% :  I think a default of 80% will get us a lot of "the fee estimation logic is broken, I want my transactions to confirm quick and a lot of them aren't confirming for 2 or 3 blocks."

RE: RPC argument:  I'm reluctant to give too many 'knobs' for the RPC interface. I think the default percentage makes sense as a command-line/bitcoin.conf option; I can imagine services that want to save on fees running with -estimatefeethreshold=0.5  (or -estimatefeethreshold=0.95 if as-fast-as-possible confirmations are needed). Setting both the number of confirmations and the estimation threshold on a transaction-by-transaction basis seems like overkill to me.

--
--
Gavin Andresen