From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sog-mx-2.v43.ch3.sourceforge.com ([172.29.43.192] helo=mx.sourceforge.net) by sfs-ml-1.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1XDNhs-00062l-56 for bitcoin-development@lists.sourceforge.net; Sat, 02 Aug 2014 01:01:56 +0000 X-ACL-Warn: Received: from mail-pa0-f53.google.com ([209.85.220.53]) by sog-mx-2.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1XDNhq-0001Py-P8 for bitcoin-development@lists.sourceforge.net; Sat, 02 Aug 2014 01:01:56 +0000 Received: by mail-pa0-f53.google.com with SMTP id rd3so6670937pab.26 for ; Fri, 01 Aug 2014 18:01:49 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:message-id:date:from:user-agent:mime-version:to :cc:subject:references:in-reply-to:content-type :content-transfer-encoding; bh=rOnnSjwrwGpAtFHSv+oxeS3faUHfdiT+BLEA1DCgrR4=; b=O+ZSqqzc8m+JXwuMnsbOSGxvh4PSAHtvWPy/mwboqH0nzTJo9EbIZrv9QQJKtppnfJ C+JAibqdtwMTwtEDd3d5AAmaQtWOCNUk6alKxT1S5ie8gIMiw7RHfiZayBOlmM39g49p VGZNqlpOsW9D4LrwlAedqidDMzo3nP4Ry8CL2TFy6XLv50GvkjpoFQJcSnRRjPBnnL2G iqavgEzlqbUchNzvHKJ90jrqKlOHcC5Vo3lIfLS81PTPJD1xle5ChaObSFyZ6Ty/oAaG epVbrCWYWU4RUK/rDy89qgUU+G9fYbYfPYNUNK195js1zjdIQKowfRyq7Y5fas2ogA98 shEg== X-Gm-Message-State: ALoCoQn4l29aXUwYUg0uWJKmVOfUMFE3SIE8WJ/nYBKdVXYUmisBNIf8rK1NAMRU7GRgMtNmuZqP X-Received: by 10.68.221.161 with SMTP id qf1mr9846959pbc.45.1406939808425; Fri, 01 Aug 2014 17:36:48 -0700 (PDT) Received: from [192.168.1.89] (99-6-44-248.lightspeed.sntcca.sbcglobal.net. [99.6.44.248]) by mx.google.com with ESMTPSA id h2sm15073333pdo.17.2014.08.01.17.36.47 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Fri, 01 Aug 2014 17:36:47 -0700 (PDT) Message-ID: <53DC329E.7090206@thinlink.com> Date: Fri, 01 Aug 2014 17:36:46 -0700 From: Tom Harding User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: Kaz Wesley References: In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Score: 0.0 (/) X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. X-Headers-End: 1XDNhq-0001Py-P8 Cc: Bitcoin Dev Subject: Re: [Bitcoin-development] deterministic transaction expiration 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: Sat, 02 Aug 2014 01:01:56 -0000 On 7/31/2014 5:58 PM, Kaz Wesley wrote: > 1. start setting nLockTime to the current height by default in newly > created transactions (or slightly below the current height, for > reorg-friendliness) Reorg-frendliness is the opposite of the rationale behind #2340, which proposes setting nLockTime at current-height + 1 to prevent "fee-sniping" reorgs... > 2. once users have had some time to upgrade to clients that set > nLockTime, start discouraging transactions without nLockTime -- > possibly with a slightly higher fee required for relay > 3. start rate-limiting relay of transactions without an nLockTime > (maybe this alone could be used to achieve [2]) > 4. add a new IsStandard rule rejecting transactions with an nLockTime > more than N blocks behind the current tip (for some fixed value N, to > be determined) > One way to proceed is implement #3753 (mempool janitor) in such a way that transactions with nLockTime are allowed to live a bit longer in the mempool (say 500 blocks) than those without (72 hours). In other words, as a first step, just actually start expiring things from the mempool in bitcoin core, and leave any relay fee adjustments or rate limiting for later. The isStandard change would be a good complement to #3753, to avoid relaying a tx that will soon expire by the nLockTime rule anyway.