Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 1F06CE66 for ; Thu, 3 Sep 2015 16:35:27 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-wi0-f180.google.com (mail-wi0-f180.google.com [209.85.212.180]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id DF84C1E8 for ; Thu, 3 Sep 2015 16:35:24 +0000 (UTC) Received: by wiclk2 with SMTP id lk2so4917032wic.0 for ; Thu, 03 Sep 2015 09:35:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=kyTeM+DHgAKs7+L3wH1uT7rWa5PS61o0r7lPHqYB86w=; b=AjSZyW2m09oBhR7sheNoJAiwlBsnj4fSZWR4PDqsztB6kYXY7/4UoPSj1O3sFsUfi7 zbWGC7Wz1xDo3/BPa1aLJpoYJwv46ayhTcBaKYe+g9Az0YX2yDc7L3FvU9M37oJ4b+Ol xfhwmPBmZZCykP11GC6LPMQiuvExUHvckKG+y2f2BmiZyHxLchxMr3DNu8cN4lAT/1wV cNnuiDz/AcwS30bze2Y8+z4DprtpJzHBZwVyX7YWhKkR6kCKiElrSWHPGkFa1Oa5Bova NEO4G1kPc9yKa+aC8TaXl1avmK9HBB5dEN3c0qTW7eRcNGDItwnAKT/0y2UXE/hMrY5y 5vTQ== MIME-Version: 1.0 X-Received: by 10.180.87.1 with SMTP id t1mr15720367wiz.33.1441298123658; Thu, 03 Sep 2015 09:35:23 -0700 (PDT) Received: by 10.28.15.11 with HTTP; Thu, 3 Sep 2015 09:35:23 -0700 (PDT) In-Reply-To: <301aa5f682f8aa408b9f6f4618095fe2@xbt.hk> References: <301aa5f682f8aa408b9f6f4618095fe2@xbt.hk> Date: Thu, 3 Sep 2015 12:35:23 -0400 Message-ID: From: Jeff Garzik To: jl2012@xbt.hk Content-Type: multipart/alternative; boundary=f46d044481afad1b83051eda5e5c X-Spam-Status: No, score=-2.7 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,HTML_MESSAGE,RCVD_IN_DNSWL_LOW autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org Cc: Bitcoin development mailing list Subject: Re: [bitcoin-dev] BIP 100 specification X-BeenThere: bitcoin-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Bitcoin Development Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 03 Sep 2015 16:35:27 -0000 --f46d044481afad1b83051eda5e5c Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Take a look at the latest update: - swiped Tier Nolan verbiage, which I agree was usefully more clear - added 'M' suffix and removed 'V' from coinbase scriptSig On Thu, Sep 3, 2015 at 12:32 PM, jl2012 via bitcoin-dev < bitcoin-dev@lists.linuxfoundation.org> wrote: > 1. I think there is no need to have resolution at byte level, while > resolution at MB level is not enough. kB would be a better choice. > > 2. In my specification a v4 block without a vote is invalid, so there is > no need to consider absent or invalid votes > > 3. We should allow miners to explicitly vote for the status quo, so they > don't need to change the coinbase vote every time the size is changed. Th= ey > may indicate it by /BV/ in the coinbase, and we should look for the first > "/BVd*/" instead of "/BVd+/" > > 4. Alternatively, miners may vote in different styles: /BV1234567/, > /BV1500K/, /BV3M/. The first one means 1.234567MB, the second one is 1.5M= B, > the last one is 3MB. The pattern is "/BV(\d+[KM]?)?/" > > Tier Nolan via bitcoin-dev =E6=96=BC 2015-09-03 07:59 =E5=AF=AB=E5=88=B0: > >> On Thu, Sep 3, 2015 at 8:57 AM, jl2012 via bitcoin-dev >> wrote: >> >> * >>> >>> hardLimit floats within the range 1-32M, inclusive. >>> >> >> Does the 32MB limit actually still exist anywhere in the code? In >> effect, it is re-instating a legacy limitation. >> >> The message size limit is to minimize the storage required per peer. >> If a 32MB block size is required, then each network input buffer must >> be at least 32MB. This makes it harder for a node to support a large >> number of peers. >> >> There is no reason why a single message is used for each block. Using >> the merkleblock message (or a different dedicated message), it would >> be possible to send messages which only contain part of a block and >> have a limited maximum size. >> >> This would allow receiving parts of a block from multiple sources. >> >> This is a separate issue but should be considered if moving past 32MB >> block sizes (or maybe as a later protocol change). >> >> * Changing hardLimit is accomplished by encoding a proposed value >>> within a block's coinbase scriptSig. >>> >>> * Votes refer to a byte value, encoded within the pattern "/BVd+/" >>> Example: /BV8000000/ votes for 8,000,000 byte hardLimit. If there is >>> more than one match with with pattern, the first match is counted. >>> >> >> Is there a need for byte resolution? Using MB resolution would use up >> much fewer bytes in the coinbase. >> >> Even with the +/- 20% rule, miners could vote for the nearest MB. >> Once the block size exceeds 5MB, then there is enough resolution >> anyway. >> >> * Absent/invalid votes and votes below minimum cap (1M) are >>> >>> counted as 1M votes. Votes above the maximum cap (32M) are counted >>> as 32M votes. >>> >> >> I think abstains should count for the status quo. Votes which are out >> of range should be clamped. >> >> Having said that, if core supports the change, then most miners will >> probably vote one way or another. >> >> New hardLimit is the median of the followings: >>> min(current hardLimit * 1.2, 20-percentile) >>> max(current hardLimit / 1.2, 80-percentile) >>> current hardLimit >>> >> >> I think this is unclear, though mathematically exact. >> >> Sort the votes for the last 12,000 blocks from lowest to highest. >> >> Blocks which don't have a vote are considered a vote for the status >> quo. >> >> Votes are limited to +/- 20% of the current value. Votes that are out >> of range are considered to vote for the nearest in range value. >> >> The raise value is defined as the vote for the 2400th highest block >> (20th percentile). >> >> The lower value is defined as the vote for the 9600th highest block >> (80th percentile). >> >> If the raise value is higher than the status quo, then the new limit >> is set to the raise value. >> >> If the lower value is lower than the status quo, then the new limit is >> set to the lower value. >> >> Otherwise, the size limit is unchanged. >> >> _______________________________________________ >> bitcoin-dev mailing list >> bitcoin-dev@lists.linuxfoundation.org >> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev >> > > _______________________________________________ > bitcoin-dev mailing list > bitcoin-dev@lists.linuxfoundation.org > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev > --f46d044481afad1b83051eda5e5c Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
Take a look at the latest update:

- swi= ped Tier Nolan verbiage, which I agree was usefully more clear
- = added 'M' suffix and removed 'V' from coinbase scriptSig


On Thu, Sep 3, 2015 at 12:32 PM, jl2012 via bitcoin-dev <bitcoin-dev@lists.linuxfoundation.org> wrote:
=
1. I think there is no need to have resoluti= on at byte level, while resolution at MB level is not enough. kB would be a= better choice.

2. In my specification a v4 block without a vote is invalid, so there is no= need to consider absent or invalid votes

3. We should allow miners to explicitly vote for the status quo, so they do= n't need to change the coinbase vote every time the size is changed. Th= ey may indicate it by /BV/ in the coinbase, and we should look for the firs= t "/BVd*/" instead of "/BVd+/"

4. Alternatively, miners may vote in different styles: /BV1234567/, /BV1500= K/, /BV3M/. The first one means 1.234567MB, the second one is 1.5MB, the la= st one is 3MB. The pattern is "/BV(\d+[KM]?)?/"

Tier Nolan via bitcoin-dev =E6=96=BC 2015-09-03 07:59 =E5=AF=AB=E5=88=B0:
On Thu, Sep 3, 2015 at 8:57 AM, jl2012 via bitcoin-dev
<bitcoin-dev@lists.linuxfoundation.org> wrote:

*

hardLimit floats within the range 1-32M, inclusive.

Does the 32MB limit actually still exist anywhere in the code?=C2=A0 In
effect, it is re-instating a legacy limitation.

The message size limit is to minimize the storage required per peer.
If a 32MB block size is required, then each network input buffer must
be at least 32MB. This makes it harder for a node to support a large
number of peers.

There is no reason why a single message is used for each block.=C2=A0 Using=
the merkleblock message (or a different dedicated message), it would
be possible to send messages which only contain part of a block and
have a limited maximum size.

This would allow receiving parts of a block from multiple sources.

This is a separate issue but should be considered if moving past 32MB
block sizes (or maybe as a later protocol change).

* Changing hardLimit is accomplished by encoding a proposed value
within a block's coinbase scriptSig.

 * Votes refer to a byte value, encoded within the pattern "/BVd+/"= ;
Example: /BV8000000/ votes for 8,000,000 byte hardLimit. If there is
more than one match with with pattern, the first match is counted.

Is there a need for byte resolution?=C2=A0 Using MB resolution would use up=
much fewer bytes in the coinbase.

Even with the +/- 20% rule, miners could vote for the nearest MB.
Once the block size exceeds 5MB, then there is enough resolution
anyway.

* Absent/invalid votes and votes below minimum cap (1M) are

counted as 1M votes. Votes above the maximum cap (32M) are counted
as 32M votes.

I think abstains should count for the status quo.=C2=A0 Votes which are out=
of range should be clamped.

Having said that, if core supports the change, then most miners will
probably vote one way or another.

New hardLimit is the median of the followings:
min(current hardLimit * 1.2, 20-percentile)
max(current hardLimit / 1.2, 80-percentile)
current hardLimit

I think this is unclear, though mathematically exact.

Sort the votes for the last 12,000 blocks from lowest to highest.

Blocks which don't have a vote are considered a vote for the status
quo.

Votes are limited to +/- 20% of the current value.=C2=A0 Votes that are out=
of range are considered to vote for the nearest in range value.

The raise value is defined as the vote for the 2400th highest block
(20th percentile).

The lower value=C2=A0 is defined as the vote for the 9600th highest block (80th percentile).

If the raise value is higher than the status quo, then the new limit
is set to the raise value.

If the lower value is lower than the status quo, then the new limit is
set to the lower value.

Otherwise, the size limit is unchanged.

_______________________________________________
bitcoin-dev mailing list
= bitcoin-dev@lists.linuxfoundation.org
https://lists.linuxfoundation.org/mail= man/listinfo/bitcoin-dev

_______________________________________________
bitcoin-dev mailing list
= bitcoin-dev@lists.linuxfoundation.org
https://lists.linuxfoundation.org/mail= man/listinfo/bitcoin-dev

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