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 C582E268 for ; Mon, 9 Nov 2015 21:04:51 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mcelrath.org (moya.mcelrath.org [50.31.3.130]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 5D2B9124 for ; Mon, 9 Nov 2015 21:04:51 +0000 (UTC) Received: from mcelrath.org (localhost [127.0.0.1]) by mcelrath.org (8.14.3/8.14.3/Debian-9.4) with ESMTP id tA9L4ndb021416 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NOT); Mon, 9 Nov 2015 21:04:49 GMT Received: (from mcelrath@localhost) by mcelrath.org (8.14.3/8.14.3/Submit) id tA9L4nkm021415; Mon, 9 Nov 2015 21:04:49 GMT X-Authentication-Warning: mcelrath.org: mcelrath set sender to bob_bitcoin@mcelrath.org using -f Date: Mon, 9 Nov 2015 21:04:49 +0000 From: Bob McElrath To: Peter Tschipper Message-ID: <20151109210449.GE5886@mcelrath.org> References: <5640F172.3010004@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5640F172.3010004@gmail.com> User-Agent: Mutt/1.5.20 (2009-06-14) X-Spam-Status: No, score=-2.2 required=5.0 tests=BAYES_00,RP_MATCHES_RCVD 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] request BIP number for: "Support for Datastream Compression" 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, 09 Nov 2015 21:04:51 -0000 I would expect that since a block contains mostly hashes and crypto signatures, it would be almost totally incompressible. I just calculated compression ratios: zlib -15% (file is LARGER) gzip 28% bzip2 25% So zlib compression is right out. How much is ~25% bandwidth savings worth to people? This seems not worth it to me. :-/ Peter Tschipper via bitcoin-dev [bitcoin-dev@lists.linuxfoundation.org] wrote: > This is my first time through this process so please bear with me. > > I opened a PR #6973 this morning for Zlib Block Compression for block > relay and at the request of @sipa this should have a BIP associated > with it. The idea is simple, to compress the datastream before > sending, initially for blocks only but it could theoretically be done > for transactions as well. Initial results show an average of 20% block > compression and taking 90 milliseconds for a full block (on a very slow > laptop) to compress. The savings will be mostly in terms of less > bandwidth used, but I would expect there to be a small performance gain > during the transmission of the blocks particularly where network latency > is higher. > > I think the BIP title, if accepted should be the more generic, "Support > for Datastream Compression" rather than the PR title of "Zlib > Compression for block relay" since it could also be used for > transactions as well at a later time. > > Thanks for your time... > _______________________________________________ > bitcoin-dev mailing list > bitcoin-dev@lists.linuxfoundation.org > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev > > > !DSPAM:5640ff47206804314022622! -- Cheers, Bob McElrath "For every complex problem, there is a solution that is simple, neat, and wrong." -- H. L. Mencken