From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191] helo=mx.sourceforge.net) by sfs-ml-1.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1TR6C6-0005Sx-9I for bitcoin-development@lists.sourceforge.net; Wed, 24 Oct 2012 19:00:46 +0000 Received-SPF: pass (sog-mx-1.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-1.v43.ch3.sourceforge.com with esmtp (Exim 4.76) id 1TR6C0-0006RC-QW for bitcoin-development@lists.sourceforge.net; Wed, 24 Oct 2012 19:00:46 +0000 Received: from [152.23.59.110] (mid-campus-dhcp00360.wireless.unc.edu [152.23.59.110]) by mail.bluematt.me (Postfix) with ESMTPSA id DB31E4C41 for ; Wed, 24 Oct 2012 19:00:34 +0000 (UTC) Message-ID: <1351105233.4731.3.camel@localhost.localdomain> From: Matt Corallo To: bitcoin-development@lists.sourceforge.net Date: Wed, 24 Oct 2012 15:00:33 -0400 In-Reply-To: References: <20121024162255.GA30290@vps7135.xlshosting.net> <20121024171104.GA31766@vps7135.xlshosting.net> 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 0.4 NO_DNS_FOR_FROM DNS: Envelope sender has no MX or A DNS records -0.0 SPF_PASS SPF: sender matches SPF record -0.7 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain X-Headers-End: 1TR6C0-0006RC-QW Subject: Re: [Bitcoin-development] Draft BIP for Bloom filtering 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: Wed, 24 Oct 2012 19:00:46 -0000 On Wed, 2012-10-24 at 14:54 -0400, Gavin Andresen wrote: > RE: sharing parts of the merkle branches when returning a 'merkleblock' : > > I think I agree that complicating the BIP for what should be a very > rare case (more than a handful of transactions in a block match the > transactions in your wallet) is the right decision. I believe you meant NOT complicating? > > I want to make sure I'm understanding this bit correctly: > > "In addition, because a merkleblock message contains only a list of > transaction hashes, any transactions that the requesting node hasn't > either received or announced with an inv will be automatically sent as > well. This avoids a slow roundtrip that would otherwise be required > (receive hashes, didn't see some of these transactions yet, ask for > them)." > > Requiring serving/relaying nodes to keep track of which transactions > they have or have not sent to their peers makes me nervous. I think > requiring an extra 'inv' round-trip would be simpler to implement and > less likely to lead to some kind of DoS attack. > Sadly that requires (potentially) more DoS potential because you require nodes to store each transaction that could be requested instead of just going ahead and forwarding them. I agree the BIP should not specify that the sending node is required to keep track of which transactions have been announced/sent to clients, however since the reference client does so currently, that implementation is significantly simpler (note that it is a bounded set in the reference client, so even the reference client doesn't really fully comply with the BIP as stated here). Matt