Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 94D92486 for ; Tue, 9 May 2017 16:27:49 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from sender-of-o52.zoho.com (sender-of-o52.zoho.com [135.84.80.217]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id D7914161 for ; Tue, 9 May 2017 16:27:48 +0000 (UTC) Received: from [10.8.8.2] (119246245241.ctinets.com [119.246.245.241]) by mx.zohomail.com with SMTPS id 1494347264716696.4950494769296; Tue, 9 May 2017 09:27:44 -0700 (PDT) From: Johnson Lau Message-Id: Content-Type: multipart/alternative; boundary="Apple-Mail=_BAC82F00-05E5-4D0A-9361-0EC61BDDA2F4" Mime-Version: 1.0 (Mac OS X Mail 10.2 \(3259\)) Date: Wed, 10 May 2017 00:27:40 +0800 In-Reply-To: To: Sergio Demian Lerner References: <7B918396-5968-4908-83C8-0F77DA8DB037@xbt.hk> X-Mailer: Apple Mail (2.3259) X-ZohoMailClient: External X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,HTML_MESSAGE, MIME_QP_LONG_LINE,RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org Cc: bitcoin-dev Subject: Re: [bitcoin-dev] Some real-world results about the current Segwit Discount X-BeenThere: bitcoin-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Bitcoin Protocol Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 09 May 2017 16:27:49 -0000 --Apple-Mail=_BAC82F00-05E5-4D0A-9361-0EC61BDDA2F4 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 No, changing from 50% to 75% is a hardfork. (75 -> 50 is a softfork). = Unless you make it pre-scheduled, or leave a special =E2=80=9Cbackdoor=E2=80= =9D softfork to change the discount. And that would certainly reduce the max tx/s with 50% discount, also = reduce the incentive to spend witness UTXO.=20 > On 10 May 2017, at 00:19, Sergio Demian Lerner = wrote: >=20 > Thanks Johnson and Hampus for the clarifications.=20 > However, I would rather do the opposite: soft-fork to 50% now, and = soft-fork again to 75% discount later if needed, because it doesn't = affect the max transactions/second.=20 >=20 > Segwit as it is today should be activated. However if it is not before = November, then for the next Segwit attempt I would choose a more = conservative 50% discount. >=20 >=20 >=20 > On Tue, May 9, 2017 at 12:45 PM, Johnson Lau > wrote: >=20 > > On 9 May 2017, at 21:49, Sergio Demian Lerner via bitcoin-dev = > wrote: > > > > > > So it seems the 75% discount has been chosen with the idea that in = the future the current transaction pattern will shift towards multisigs. = This is not a bad idea, as it's the only direction Bitcoin can scale = without a HF. > > But it's a bad idea if we end up doing, for example, a 2X blocksize = increase HF in the future. In that case it's much better to use a 50% = witness discount, and do not make scaling risky by making the worse case = block size 8 Mbytes, when it could have been 2*2.7=3D5.4 Mbytes. > > >=20 > As we could change any parameter in a hardfork, I don=E2=80=99t think = this has any relation with the current BIP141 proposal. We could just = use 75% in a softfork, and change that to a different value (or = completely redefine the definition of weight) with a hardfork later. >=20 >=20 >=20 --Apple-Mail=_BAC82F00-05E5-4D0A-9361-0EC61BDDA2F4 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8
No, changing from 50% to 75% is a hardfork. = (75 -> 50 is a softfork). Unless you make it pre-scheduled, or leave = a special =E2=80=9Cbackdoor=E2=80=9D softfork to change the = discount.

And = that would certainly reduce the max tx/s with 50% discount, also reduce = the incentive to spend witness UTXO. 

On = 10 May 2017, at 00:19, Sergio Demian Lerner <sergio.d.lerner@gmail.com> wrote:

Thanks Johnson and Hampus for the clarifications. 
However, I would rather do the opposite: soft-fork to 50% = now, and soft-fork again to 75% discount later if needed, because it = doesn't affect the max transactions/second. 

Segwit as it is today should be = activated. However if it is not before November, then for the next = Segwit attempt I would choose a more conservative 50% = discount.



On Tue, May 9, 2017 at 12:45 PM, = Johnson Lau <jl2012@xbt.hk> wrote:

> On 9 May 2017, at 21:49, Sergio Demian Lerner via bitcoin-dev = <bitcoin-dev@lists.linuxfoundation.org> = wrote:
>
>
> So it seems the 75% discount has been chosen with the idea that in = the future the current transaction pattern will shift towards multisigs. = This is not a bad idea, as it's the only direction Bitcoin can scale = without a HF.
> But it's a bad idea if we end up doing, for example, a 2X blocksize = increase HF in the future. In that case it's much better to use a 50% = witness discount, and do not make scaling risky by making the worse case = block size 8 Mbytes, when it could have been 2*2.7=3D5.4 Mbytes.
>

As we could change any parameter in a hardfork, I don=E2=80=99t = think this has any relation with the current BIP141 proposal. We could = just use 75% in a softfork, and change that to a different value (or = completely redefine the definition of weight) with a hardfork later.




= --Apple-Mail=_BAC82F00-05E5-4D0A-9361-0EC61BDDA2F4--