Received-SPF: pass (sog-mx-2.v43.ch3.sourceforge.com: domain of gmail.com
	designates 209.85.223.175 as permitted sender)
	client-ip=209.85.223.175; envelope-from=gmaxwell@gmail.com;
	helo=mail-ie0-f175.google.com; 
MIME-Version: 1.0
In-Reply-To: <CAGQP0AHdmyMhrOA1mMqjxobu8S0r6OnvducV7H=HFaiv-PR+rw@mail.gmail.com>
References: <CANEZrP2r6sVC_63xx6U7XLbFkukrFEhq-mGAse3vHJ6nf3Q1cw@mail.gmail.com>
	<CA+8xBpen9o3Oji0ePsbU-ZQCSpFO+tAZt63LaOsR30KULYbUhQ@mail.gmail.com>
	<CAAS2fgR7yiyTWyuwAqxsnAb-xv9bmBFUxDwJhEkRH1PCP=pzJw@mail.gmail.com>
	<CANEZrP03R_6nQQ-_uxdF++g-ON4ynsNBTDFqmVt2ZnLy49GqZg@mail.gmail.com>
	<CAGQP0AHdmyMhrOA1mMqjxobu8S0r6OnvducV7H=HFaiv-PR+rw@mail.gmail.com>
Date: Tue, 25 Sep 2012 13:52:10 -0400
Message-ID: <CAAS2fgRmS0ssKJvJsrhpbmj4awViexhQbQJB-TUU1gUQ8TzOeg@mail.gmail.com>
From: Gregory Maxwell <gmaxwell@gmail.com>
To: =?UTF-8?B?Sm9yZ2UgVGltw7Nu?= <timon.elviejo@gmail.com>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: quoted-printable
Cc: Bitcoin Development <bitcoin-development@lists.sourceforge.net>
Subject: Re: [Bitcoin-development] Large backlog of transactions building up?
Precedence: list

On Tue, Sep 25, 2012 at 1:34 PM, Jorge Tim=C3=B3n <timon.elviejo@gmail.com>=
 wrote:
> On 9/23/12, Jeff Garzik <jgarzik@exmulti.com> wrote:
>> - provides a deterministic lifetime for a TX; if you KNOW a TX will
>> disappear 144 blocks (24 hours) after you stop transmitting, then it
>> is probably safe to initiate recovery procedures and perhaps revise
>> the transaction
>> - prevents zombie TXs from littering memory... they hang around,
>> wasting resources, but never get confirmed
>
> I don't understand. Can the chain enforce this number?
> Why can't clients delete all those transactions right now?

This is discussion about transactions which are not in the chain yet.

> On 9/23/12, Gregory Maxwell <gmaxwell@gmail.com> wrote:
>> There are bursts of weird transactions (e.g. someone was flooding zero
>> value txn a few weeks ago; before that there were some enormous series
>> of double-spend induced orphans), and other sustained loads that quite
>> a few miners are intentionally excluding.
>
> Why clients store transactions that don't obey the current rules of
> the chain at all?

The double spending transaction is not stored=E2=80=94 which is, in fact, t=
he
problem which creates these huge chain. When a transaction depending
on the doublespend is received we do not know its parent (because we
dropped it because it was a rule violation) so we keep it around as an
orphan hoping its parent arrives.

The software could maintain a cache of rejected txids to consult for
orphan txn's parents, but it would need to be dropped any time there
is a reorg so I don't know how useful it would be.