From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 75B3BAAC for ; Mon, 22 Jun 2015 21:39:13 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-pd0-f181.google.com (mail-pd0-f181.google.com [209.85.192.181]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id EA93B141 for ; Mon, 22 Jun 2015 21:39:12 +0000 (UTC) Received: by pdbki1 with SMTP id ki1so146718452pdb.1 for ; Mon, 22 Jun 2015 14:39:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=message-id:disposition-notification-to:date:from:user-agent :mime-version:to:subject:references:in-reply-to:content-type; bh=uJPLqf2O8NVA1691sYKY1MS2svDpFAn9aOveV5epwzc=; b=U5MyHTZNXLVG9Vb3P5DkIkPMwa049rMLxRYvSuNgv9CsjkHO3NHIuoTacAQOr3XErS kxP/IwxMGBFSkTbWlOoZk9g/jK7ezzXbre+oxZD1oYhnmSgSqP2IbOBxFIFR3tp5NmWE 2Bs/fY0A7GAjFZOVLQRBvRtQ2sYL110ML5fMyUqhKX9RBNB/gzgCPorb3ioRy381UWDR 4KIrnJbDBGp3Qa2VVGukfQZ65R8Xse9D95vIj97dNGquH46p2q2p04wSKWycLtWeTEIL BPdGiSIpJQnyn7VxgDgXRD77TVe3ZYsyuOkDnVdlaA35jL06zQWsTQYCtpQUPQm+ntd+ Dndw== X-Received: by 10.70.32.66 with SMTP id g2mr43887241pdi.82.1435009152570; Mon, 22 Jun 2015 14:39:12 -0700 (PDT) Received: from [10.45.134.9] (c-24-5-81-164.hsd1.ca.comcast.net. [24.5.81.164]) by mx.google.com with ESMTPSA id f1sm20897965pdp.24.2015.06.22.14.39.11 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 22 Jun 2015 14:39:11 -0700 (PDT) Message-ID: <5588807B.7030400@gmail.com> Date: Mon, 22 Jun 2015 14:39:07 -0700 From: Patrick Strateman User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.7.0 MIME-Version: 1.0 To: bitcoin-dev@lists.linuxfoundation.org References: <20150622205420.GA8892@savin.petertodd.org> In-Reply-To: Content-Type: multipart/alternative; boundary="------------020804050407050102040706" 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 Subject: Re: [bitcoin-dev] Draft BIP : fixed-schedule block size increase 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: Mon, 22 Jun 2015 21:39:13 -0000 This is a multi-part message in MIME format. --------------020804050407050102040706 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit If you truly have a consensus then the rational behavior is to permanently change the nodes behavior after the trigger. On 06/22/2015 02:21 PM, Gavin Andresen wrote: > On Mon, Jun 22, 2015 at 4:54 PM, Peter Todd > wrote: > > > Since it's possible that block timestamps aren't chronological > in order, what would happen if a block following a size increase > trigger is back in the past before the size increase? Would that > block have a lower size restriction again? Would using block > height not be a more stable number to work with? > > In the nVersion bits proposal that I co-authored we solved that > issue by > comparing the timestamp against the median time, which is > guaranteed by > the protocol rules to monotonically advance. > > > That complicates the implementation quite a bit. > > I mostly implemented a variant that replaced the MAX_BLOCK_SIZE > constant with a function that took both a timestamp and a block > height, and there are several places in the current reference > implementation where digging out the block height (or, worse, > calculating the median timestamp for the block) would involve changing > quite a few functions in the call-chain or acquiring the cs_main lock > to consult the current best chain. > > -- > -- > Gavin Andresen > > > _______________________________________________ > bitcoin-dev mailing list > bitcoin-dev@lists.linuxfoundation.org > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev --------------020804050407050102040706 Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: 7bit If you truly have a consensus then the rational behavior is to permanently change the nodes behavior after the trigger.

On 06/22/2015 02:21 PM, Gavin Andresen wrote:
On Mon, Jun 22, 2015 at 4:54 PM, Peter Todd <pete@petertodd.org> wrote:
> Since it's possible that block timestamps aren't chronological in order, what would happen if a block following a size increase trigger is back in the past before the size increase? Would that block have a lower size restriction again? Would using block height not be a more stable number to work with?

In the nVersion bits proposal that I co-authored we solved that issue by
comparing the timestamp against the median time, which is guaranteed by
the protocol rules to monotonically advance.

That complicates the implementation quite a bit.

I mostly implemented a variant that replaced the MAX_BLOCK_SIZE constant with a function that took both a timestamp and a block height, and there are several places in the current reference implementation where digging out the block height (or, worse, calculating the median timestamp for the block) would involve changing quite a few functions in the call-chain or acquiring the cs_main lock to consult the current best chain.

--
--
Gavin Andresen


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