Current transaction fee criteria (0.8.1+)?

[simondlr]

Hi.

After these two issues on Github (https://github.com/bitcoin/bitcoin/pull/2403 and https://github.com/bitcoin/bitcoin/pull/2577), I'm having trouble understanding how to determine when a transaction fee needs to be applied (and by how much). The wiki page also seems out of date since the default mintxfee has been set to 0.0001BTC (issue 2403).

If I understand correctly, it is determined by size of the inputs and outputs (http://bitcoin.stackexchange.com/questions/1195/how-to-calculate-transaction-size-before-sending/3011), coin age, and priority for block inclusion.

If we assume that the coin age priority is needed (let's say its all new coins), it is not dust, and that there is no competition for spaces in blocks, that the tx fee is 0.0001btc/kb? Is there a way to determine, once block priority becomes competitive if the tx fee needs to be raised? Is it okay to just anyway pay 0.0001btc/kb regardless of the other criteria?

Would really appreciate some clarification!

[jonytk]

the 0.0001 tx fee is in 0.81.
today everyone is supposed to update to 0.8,
so still not being applyied.

I would also like to know when we can start sending 0.0001 fee tx.
many services and webpage should update then.

i got transactions of 0.1 without fee stuck on limbo,
while a few days ago it went thru...
 so it's kind of random depending on coin age.

[deepceleron]

In testing the patch for 0.8.2 that lowers the default included transaction fee, I have had fee-requiring transactions take from the next block to three hours when sending with the reduced fee over the current Bitcoin network. As pools should not be using 0.8.2 yet (but are free to modify Bitcoin and can implement whatever rules they want), a fee below the default sending minimum of 0.0005 per kB for version 0.3.23-0.8.1, for transactions that require one, are considered to have been sent with no fee by miners and must compete for the small "free transaction" space reserved in blocks.

There is also a minimum relay fee, which is and still will be 0.0001/kB. Standard nodes won't retransmit fee-requiring transactions below this threshold to prevent network DOS.

Priority rules (documented on the wiki) determine when a transaction is eligible to be free based on the number of confirmations and the input value of the coins funding the transaction. Qualifying free transactions must still compete for a limited space, and depending on the number and type of pending transactions, may take significantly longer than if they were sent with a voluntary fee.