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-2.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1UFOJ4-0001Hw-Aa for bitcoin-development@lists.sourceforge.net; Tue, 12 Mar 2013 12:27:50 +0000 X-ACL-Warn: Received: from 2508ds5-oebr.1.fullrate.dk ([90.184.5.129] helo=mail.ceptacle.com) by sog-mx-2.v43.ch3.sourceforge.com with esmtp (Exim 4.76) id 1UFOJ0-00028p-Hs for bitcoin-development@lists.sourceforge.net; Tue, 12 Mar 2013 12:27:50 +0000 Received: from localhost (localhost [127.0.0.1]) by mail.ceptacle.com (Postfix) with ESMTP id BABEB2B86121; Tue, 12 Mar 2013 13:27:40 +0100 (CET) X-Virus-Scanned: amavisd-new at ceptacle.com Received: from mail.ceptacle.com ([127.0.0.1]) by localhost (server.ceptacle.private [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id tbakdGFduNLP; Tue, 12 Mar 2013 13:27:33 +0100 (CET) Received: from [109.105.106.206] (unknown [109.105.106.206]) by mail.ceptacle.com (Postfix) with ESMTPSA id 9B1552B8610A; Tue, 12 Mar 2013 13:27:33 +0100 (CET) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 6.2 \(1499\)) From: Michael Gronager In-Reply-To: Date: Tue, 12 Mar 2013 13:27:32 +0100 Content-Transfer-Encoding: quoted-printable Message-Id: References: <20130312114426.GA3701@vps7135.xlshosting.net> To: Mike Hearn X-Mailer: Apple Mail (2.1499) 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: 1UFOJ0-00028p-Hs Cc: Bitcoin Dev Subject: Re: [Bitcoin-development] Warning: many 0.7 nodes break on large number of tx/block; fork risk 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: Tue, 12 Mar 2013 12:27:50 -0000 Well a reversed upgrade is an upgrade that went wrong ;) Anyway, the incident makes it even more important for people to upgrade, = well except, perhaps, for miners... Forks are caused by rejection criteria, hence:=20 1. If you introduce new rejection criteria in an upgrade miners should = upgrade _first_. 2. If you loosen some rejection criteria miners should upgrade _last_. 3. If you keep the same criteria assume 2. /M On 12/03/2013, at 13:11, Mike Hearn wrote: > I'm not even sure I'd say the upgrade "went wrong". The problem if > anything is the upgrade didn't happen fast enough. If we had run out > of block space a few months from now, or if miners/merchants/exchanges > had upgraded faster, it'd have made more sense to just roll forward > and tolerate the loss of the older clients. >=20 > This really reinforces the importance of keeping nodes up to date. >=20 > On Tue, Mar 12, 2013 at 12:44 PM, Pieter Wuille = wrote: >> On Tue, Mar 12, 2013 at 11:13:09AM +0100, Michael Gronager wrote: >>> Yes, 0.7 (yes 0.7!) was not sufficiently tested it had an = undocumented and unknown criteria for block rejection, hence the upgrade = went wrong. >>=20 >> We're using "0.7" as a short moniker for all clients, but this was a = limitation that all >> BDB-based bitcoins ever had. The bug is simply a limit in the number = of lock objects >> that was reached. >>=20 >> It's ironic that 0.8 was supposed to solve all problems we had due to = BDB (except the >> wallet...), but now it seems it's still coming back to haunt us. I = really hated telling >> miners to go back to 0.7, given all efforts to make 0.8 signficantly = more tolerable... >>=20 >>> More space in the block is needed indeed, but the real problem you = are describing is actually not missing space in the block, but proper = handling of mem-pool transactions. They should be pruned on two = criteria: >>>=20 >>> 1. if they gets to old >24hr >>> 2. if the client is running out of space, then the oldest should = probably be pruned >>>=20 >>> clients are anyway keeping, and re-relaying, their own transactions = and hence it would mean only little, and only little for clients. = Dropping free / old transaction is a much a better behavior than = dying... Even a scheme where the client dropped all or random mempool = txes would be a tolerable way of handling things (dropping all is = similar to a restart, except for no user intervention). >>=20 >> Right now, mempools are relatively small in memory usage, but with = small block sizes, >> it indeed risks going up. In 0.8, conflicting (=3Ddouble spending) = transactions in the >> chain cause clearing the mempool of conflicts, so at least the = mempool is bounded by >> the size of the UTXO subset being spent. Dropping transactions from = the memory pool >> when they run out of space seems a correct solution. I'm less = convinced about a >> deterministic time-based rule, as that creates a double spending = incentive at that >> time, and a counter incentive to spam the network with your = risking-to-be-cleared >> transaction as well. >>=20 >> Regarding the block space, we've seen the pct% of one single block = chain space consumer >> grow simultaneously with the introduction of larger blocks, so I'm = not actually convinced >> there is right now a big need for larger blocks (note: right now). = The competition for >> block chain space is mostly an issue for client software which = doesn't deal correctly >> with non-confirming transactions, and misleading users. It's mostly a = usability problem >> now, but increasing block sizes isn't guaranteed to fix that; it may = just make more >> space for spam. >>=20 >> However, the presence of this bug, and the fact that a full solution = is available (0.8), >> probably helps achieving consensus fixing it (=3Da hardfork) is = needed, and we should take >> advantage of that. But please, let's not rush things... >>=20 >> -- >> Piter >=20 > = --------------------------------------------------------------------------= ---- > Symantec Endpoint Protection 12 positioned as A LEADER in The = Forrester =20 > Wave(TM): Endpoint Security, Q1 2013 and "remains a good choice" in = the =20 > endpoint security space. For insight on selecting the right partner to=20= > tackle endpoint security challenges, access the full report.=20 > http://p.sf.net/sfu/symantec-dev2dev > _______________________________________________ > Bitcoin-development mailing list > Bitcoin-development@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/bitcoin-development