From: Tomas <tomas@tomasvdw•nl>
To: Gregory Maxwell <greg@xiph•org>
Cc: Bitcoin Protocol Discussion <bitcoin-dev@lists•linuxfoundation.org>
Subject: Re: [bitcoin-dev] Using a storage engine without UTXO-index
Date: Sat, 08 Apr 2017 09:28:48 +0200 [thread overview]
Message-ID: <1491636528.2474173.938219072.54C44183@webmail.messagingengine.com> (raw)
In-Reply-To: <CAAS2fgTWyX5M-xcELC2vDvGfs01tbGYkpZJCSeNbvn_p4Ecjqg@mail.gmail.com>
On Sat, Apr 8, 2017, at 02:44, Gregory Maxwell wrote:
> As you note that the output costs still bound the resource
> requirements.
Resource cost is not just a measure of storage requirement; data that
needs to be accessed during peak load induce more cost then data only
used during base load or only rarely used.
> Latency related costs in Bitcoin Core also do not depend on the number
> of outputs in transactions in a block. When a transaction is handled
> it goes into an in-memory buffer and only gets flushed later if isn't
> spent before the buffer fills. A block will take more time to
> validate with more inputs, same as you observer, but the aggregate
> resource usage for users depends significantly on outputs (so, in fact
> there is even further misaligned incentives than just the fact that
> small outputs have a outsized long term cost).
In Core, when a block comes the inputs are checked against the UTXO set
(which grows with outputs) even if pre-synced, to verify order. Am I
wrong there? This is not in the case in bitcrust; it is instead checked
against the spend-tree (which grows with inputs).
How "significant" this is, I neither know nor claim, but it is an
interesting difference.
> Then I think you may want to retract the claim that "As this solution,
> reversing the costs of outputs and inputs, [...] updates to the
> protocol addressing the UTXO growth, might not be worth considering
> *protocol improvements* "
I think you are being a bit harsh here . I am also clearly explaining
the difference only applies to peak load, and just making a suggestion.
I simply want to stress the importance of protocol / implementation
separation as even though you are correct UTXO data is always a resource
cost for script validation (as I also state), the ratio of different
costs are not necessarily *identical* across implementation.
Note that the converse also holds: In bitcrust, if the last few blocks
contain many inputs, the peak load verification for this block is
slower. This is not the case in Core.
Tomas
next prev parent reply other threads:[~2017-04-08 7:28 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-06 22:12 Tomas
2017-04-06 23:38 ` Eric Voskuil
2017-04-07 0:17 ` Tomas
2017-04-08 22:37 ` Eric Voskuil
2017-04-08 23:58 ` Tomas
2017-04-11 1:44 ` Eric Voskuil
2017-04-11 8:43 ` Tomas
2017-04-11 9:41 ` Eric Voskuil
2017-04-11 10:04 ` Tomas
[not found] ` <CAAS2fgTEMCkDWdhCWt1EsUrnt3+Z_8m+Y1PTsff5Rc0CBnCKWQ@mail.gmail.com>
2017-04-07 0:48 ` Tomas
2017-04-07 1:09 ` Gregory Maxwell
2017-04-07 1:29 ` Tomas
2017-04-07 18:52 ` Tom Harding
2017-04-07 19:42 ` Gregory Maxwell
2017-04-08 18:27 ` Tom Harding
2017-04-08 19:23 ` Tomas
2017-04-07 7:55 ` Marcos mayorga
2017-04-07 8:47 ` Tomas
2017-04-07 14:14 ` Greg Sanders
2017-04-07 16:02 ` Tomas
2017-04-07 18:18 ` Gregory Maxwell
2017-04-07 18:39 ` Bram Cohen
2017-04-07 19:55 ` Eric Voskuil
2017-04-07 21:44 ` Tomas
2017-04-07 23:51 ` Eric Voskuil
2017-04-07 21:14 ` Tomas
2017-04-08 0:44 ` Gregory Maxwell
2017-04-08 7:28 ` Tomas [this message]
2017-04-08 19:23 ` Johnson Lau
2017-04-08 19:56 ` Tomas
2017-04-08 20:21 ` Johnson Lau
2017-04-08 20:42 ` Tomas
2017-04-08 22:12 ` Gregory Maxwell
2017-04-08 22:34 ` Tomas
2017-04-08 21:22 ` Troy Benjegerdes
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