Re: [Bitcoin-development] Large backlog of transactions building up?

[Gregory Maxwell <gmaxwell@gmail.com>]

On Tue, Sep 25, 2012 at 1:34 PM, Jorge Timón <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— which is, in fact, the
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.