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 5FA93360 for ; Sat, 18 Jul 2015 18:53:04 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from outmail149080.authsmtp.com (outmail149080.authsmtp.com [62.13.149.80]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id A7A4F103 for ; Sat, 18 Jul 2015 18:53:03 +0000 (UTC) Received: from mail-c235.authsmtp.com (mail-c235.authsmtp.com [62.13.128.235]) by punt17.authsmtp.com (8.14.2/8.14.2/) with ESMTP id t6IIr2NJ001883 for ; Sat, 18 Jul 2015 19:53:02 +0100 (BST) Received: from muck (bas1-clarkson16-1177732471.dsl.bell.ca [70.50.197.119]) (authenticated bits=128) by mail.authsmtp.com (8.14.2/8.14.2/) with ESMTP id t6IIqwsh098727 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO) for ; Sat, 18 Jul 2015 19:53:01 +0100 (BST) Date: Sun, 19 Jul 2015 03:52:59 +0900 From: Peter Todd To: bitcoin-dev@lists.linuxfoundation.org Message-ID: <20150718185259.GA3477@muck> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="OgqxwSJOaUobr8KG" Content-Disposition: inline X-Server-Quench: 37089be1-2d7e-11e5-b397-002590a15da7 X-AuthReport-Spam: If SPAM / abuse - report it at: http://www.authsmtp.com/abuse X-AuthRoute: OCd2Yg0TA1ZNQRgX IjsJECJaVQIpKltL GxAVJwpGK10IU0Fd P1hyKltILEZaQVBf Ri5dBBEKBAw1ADwr dVUTOktcalU0Gll1 UkhIR0JTHQ9tAhYB B1AZUgd3dxtHcXlu ZEdrQXVTW1t7OwJ7 OzcVUi5eZW5ob2IY HkVffwUacwRKdhYX P1FiVicKNHgGZy9l WgVobm90ZW0FdXUN S1hQIVtNV2oMViEx DwoPFDErDAUDSig/ ZxVuL1MZBEEWNhJ6 cVUmQxoCPhsbG0VY GE1AG24x X-Authentic-SMTP: 61633532353630.1023:706 X-AuthFastPath: 0 (Was 255) X-AuthSMTP-Origin: 70.50.197.119/587 X-AuthVirus-Status: No virus detected - but ensure you scan with your own anti-virus system. X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00,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: [bitcoin-dev] Do we really need a mempool? (for relay nodes) 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: Sat, 18 Jul 2015 18:53:04 -0000 --OgqxwSJOaUobr8KG Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable As in, do relay nodes need to keep a record of the transactions they've relayed? Strictly speaking, the answer is no: one a tx is relayed modulo DoS concerns the entire thing can be discarded by the node. (unconfirmed txs spending other unconfirmed txs can be handled by creating packages of transactions, evaluated as a whole) To mitigate DoS concerns, we of course have to have some per-UTXO limit on bandwidth relayed, but that task can be accomplished by simply maintaining some kind of per-UTXO record of bandwidth used. For instance if the weighted fee and fee/KB were recorded, and forced to - say - double for each additional tx relayed that spent a given UTXO you would have a clear and simple upper limit of lifetime bandwidth. Equally it's easy to limit bandwidth moment to moment by asking peers for highest fee/KB transactions they advertise first, stopping when our bandwidth limit is reached. You probably could even remove IsStandard() pretty much entirely with the right increasingly expensive "replacement" policy, relying on it alone to provide anti-DoS. Obviously this would simplify some of the debates around mining policy! This could even be re-used for scalable a general-purpose messaging network paid by coin ownership if the UTXO set is split up, and some kind of expiration over time policy is implemented. Miners of course would still want to have a mempool, but that codebase may prove simpler if it doesn't have to work double-duty for relaying as well. --=20 'peter'[:-1]@petertodd.org 00000000000000000b675c4d825a10c278b8d63ee4df90a19393f3b6498fd073 --OgqxwSJOaUobr8KG Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- iQGqBAEBCACVBQJVqqCIXhSAAAAAABUAQGJsb2NraGFzaEBiaXRjb2luLm9yZzAw MDAwMDAwMDAwMDAwMDAwYjY3NWM0ZDgyNWExMGMyNzhiOGQ2M2VlNGRmOTBhMTkz OTNmM2I2NDk4ZmQwNzMvFIAAAAAAFQARcGthLWFkZHJlc3NAZ251cGcub3JncGV0 ZUBwZXRlcnRvZC5vcmcACgkQwIXyHOf0udxaRQf4uNJANiE9GYAubmKRVsg70gfJ gpuX7DMcgJ023AaXtpX43S9hAI9NvFTlEbBHySwwP0uwgV10bE+VJm3Plz7LNZ5k uDaDxl8mpqcfWq0LneTt1zoMn9KChu8JB6zbL71Y1/P7oGtlcfazM4YZFWFB0U0q vQntAK6GAILibtpe8wbI/cvvhRUp2/jML395GVnM+VwCL1KdHLs/QIZAwl9J/1bK KgZr3BKjToEs+d0fyWOCsGSoCPXXnOyWWhaZlDKenLKhQIQBp1EDoVd8yTSJkuXG IShKtNgPx7VGCqD8ZbW3BXcIbowEfdK5rLp1Jf8abyckhsv3M8yK3DURtwO8 =tBhq -----END PGP SIGNATURE----- --OgqxwSJOaUobr8KG--