From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sog-mx-4.v43.ch3.sourceforge.com ([172.29.43.194] helo=mx.sourceforge.net) by sfs-ml-4.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1TBA3F-0003Lb-7i for bitcoin-development@lists.sourceforge.net; Mon, 10 Sep 2012 19:53:45 +0000 Received-SPF: pass (sog-mx-4.v43.ch3.sourceforge.com: domain of bluematt.me designates 173.246.101.161 as permitted sender) client-ip=173.246.101.161; envelope-from=bitcoin-list@bluematt.me; helo=mail.bluematt.me; Received: from vps.bluematt.me ([173.246.101.161] helo=mail.bluematt.me) by sog-mx-4.v43.ch3.sourceforge.com with esmtp (Exim 4.76) id 1TBA3E-0001HN-0f for bitcoin-development@lists.sourceforge.net; Mon, 10 Sep 2012 19:53:45 +0000 Received: from [192.168.1.2] (dhcp00757.north-resnet.unc.edu [152.23.202.249]) by mail.bluematt.me (Postfix) with ESMTPSA id 99B434930 for ; Mon, 10 Sep 2012 19:53:38 +0000 (UTC) Message-ID: <1347306813.1419.20.camel@localhost.localdomain> From: Matt Corallo To: bitcoin-development@lists.sourceforge.net Date: Mon, 10 Sep 2012 15:53:33 -0400 In-Reply-To: <239CFE18-302F-47F1-8686-67297FDDFB3C@godofgod.co.uk> References: <201209101859.05009.luke@dashjr.org> <239CFE18-302F-47F1-8686-67297FDDFB3C@godofgod.co.uk> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.4.4 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-Spam-Score: -1.9 (-) X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. -1.5 SPF_CHECK_PASS SPF reports sender host as permitted sender for sender-domain -0.0 SPF_PASS SPF: sender matches SPF record -0.4 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain X-Headers-End: 1TBA3E-0001HN-0f Subject: Re: [Bitcoin-development] Segmented Block Relaying BIP draft. X-BeenThere: bitcoin-development@lists.sourceforge.net X-Mailman-Version: 2.1.9 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 10 Sep 2012 19:53:45 -0000 It seems to me the whole idea of segmenting blocks would add very little (to nothing) with any sane block size. Sure, if a block were to be 10GB, it may make sense. However, even in that case, it would be easier to relay a list of tx hashes (which may be a bit expensive) and txes separately instead of using a notion of block segments. That said, I don't see blocks ever being that large and if they do become that large, as only a few full nodes will remain, upgrading their protocol would be (relatively) easy. I would instead encourage focus on decreasing block relay times for the current network and as blocks approach 10MB (so that they can approach 10MB). Matt On Mon, 2012-09-10 at 20:34 +0100, Matthew Mitchell wrote: > Do you mean getdata? Here is the reason for the 6 new messages: > > > getseginv,seginv - These are for learning about what segments of a > block a node has. Else you could remove these messages and simply have > nodes advertise blocks via inventory messages. In this case nodes > would have to wait until they had fully received a block before > relaying anything. No longer is there a benefit with nodes being able > to relay segments of blocks before they have received the entire > block. > > > gettreelevel,treelevel - These are to received a level of > the merle tree. Instead you might use get data but gettreelevel is > more compact than get data and is clearly differentiates itself as > part of the new protocol. Perhaps these messages could include the > block headers alongside the hashes and you could request many at once > like with the getheaders message? If you skip these messages, then you > could verify the transactions at the end but there would be problems > when peers give bad segments where data would need to be downloaded > again. > > > getsegment,segment - These are clearly important to request and > receive segments for the blocks. These allows for nodes > to download arbitrary segments of blocks. The optimum number of > segments could be calculated by node software using measurements of > download speeds and latency times, the number of connections and how > likely redundancy is to occur. If a node is up-to-date and likely has > many of the transactions in blocks, it can start asking for the > deepest merle level (tx hashes) and ask nodes for segments, avoiding > transactions it already has. > > > I'll get around to doing measurements myself sometime to estimate the > benefit of this proposal. It will certainly be beneficial when block > sizes reach some size but not much is really known except what can be > assumed/guessed. > > > I should also mention the bitcointalk topic > here: https://bitcointalk.org/index.php?topic=103295.0 > > On 10 Sep 2012, at 19:59, "Luke-Jr" wrote: > > > > Most of the problem with block propagation lies in implementation, > > not > > protocol... Distributing missing transaction on an as-needed basis > > is a > > possible improvement at the protocol level, but there hasn't (AFAIK) > > been any > > research into whether the little benefit outweighs the cost yet. In > > any case, > > I don't see why 6 new messages are needed instead of simply adding a > > single > > new type to getinv?