<div dir="ltr">I think the biggest problem with merging CPFP right now is that at least in its current implementation it is not efficient enough in certain situations,.</div><div class="gmail_extra"><br><div class="gmail_quote">On Fri, Jul 10, 2015 at 1:02 PM, Justus Ranvier <span dir="ltr"><<a href="mailto:justus@openbitcoinprivacyproject.org" target="_blank">justus@openbitcoinprivacyproject.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><span class="">On 07/10/2015 11:31 AM, Jeff Garzik wrote:<br>
> This is a good explanation but it does not address reachability. TX_a, the<br>
> first tx sent out on the network, presumably has insufficient fee to get<br>
> mined - which also means it did not necessarily even reach all miners.<br>
><br>
> Simply sending out TX_b with added fee does not guarantee that nodes<br>
> suddenly have TX_a, which they may have ignored/dropped before.<br>
<br>
</span>I'm not sure why that's actually a problem.<br>
<br>
CPFP is initiated by the recipient of the parent transaction, and so if<br>
the recipient is creating this transaction in the first place they must<br>
have a copy of the parent transaction which can/should broadcast at the<br>
same time.<br>
<br>
If the child reaches a CPFP miner, then presumably the parents made it<br>
as well (any path between the sender and the miner that doesn't relay<br>
the parent should reject the child as trying to spend non-existent<br>
coins), so both of the transactions can be mined at the same time.<br>
<span class="HOEnZb"><font color="#888888"><br>
--<br>
Justus Ranvier<br>
Open Bitcoin Privacy Project<br>
<a href="http://www.openbitcoinprivacyproject.org/" rel="noreferrer" target="_blank">http://www.openbitcoinprivacyproject.org/</a><br>
<a href="mailto:justus@openbitcoinprivacyproject.org">justus@openbitcoinprivacyproject.org</a><br>
E7AD 8215 8497 3673 6D9E 61C4 2A5F DA70 EAD9 E623<br>
</font></span><br>_______________________________________________<br>
bitcoin-dev mailing list<br>
<a href="mailto:bitcoin-dev@lists.linuxfoundation.org">bitcoin-dev@lists.linuxfoundation.org</a><br>
<a href="https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev" rel="noreferrer" target="_blank">https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev</a><br>
<br></blockquote></div><br></div>