Return-Path: Received: from smtp3.osuosl.org (smtp3.osuosl.org [IPv6:2605:bc80:3010::136]) by lists.linuxfoundation.org (Postfix) with ESMTP id 71354C000B for ; Tue, 1 Feb 2022 01:56:46 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp3.osuosl.org (Postfix) with ESMTP id 4F13260F57 for ; Tue, 1 Feb 2022 01:56:46 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org X-Spam-Flag: NO X-Spam-Score: -1.499 X-Spam-Level: X-Spam-Status: No, score=-1.499 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, KHOP_HELO_FCRDNS=0.398, SPF_HELO_NONE=0.001, SPF_NONE=0.001, UNPARSEABLE_RELAY=0.001] autolearn=no autolearn_force=no Received: from smtp3.osuosl.org ([127.0.0.1]) by localhost (smtp3.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id PVAsbYTDNPmd for ; Tue, 1 Feb 2022 01:56:45 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.8.0 Received: from azure.erisian.com.au (cerulean.erisian.com.au [139.162.42.226]) by smtp3.osuosl.org (Postfix) with ESMTPS id 99A3360F48 for ; Tue, 1 Feb 2022 01:56:45 +0000 (UTC) Received: from aj@azure.erisian.com.au (helo=sapphire.erisian.com.au) by azure.erisian.com.au with esmtpsa (Exim 4.92 #3 (Debian)) id 1nEiPR-0001dW-62; Tue, 01 Feb 2022 11:56:42 +1000 Received: by sapphire.erisian.com.au (sSMTP sendmail emulation); Tue, 01 Feb 2022 11:56:37 +1000 Date: Tue, 1 Feb 2022 11:56:37 +1000 From: Anthony Towns To: Bastien TEINTURIER , Bitcoin Protocol Discussion Message-ID: <20220201015637.GA4302@erisian.com.au> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-Spam-Score-int: -18 X-Spam-Bar: - Subject: Re: [bitcoin-dev] Improving RBF Policy X-BeenThere: bitcoin-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Bitcoin Protocol Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 01 Feb 2022 01:56:46 -0000 On Mon, Jan 31, 2022 at 04:57:52PM +0100, Bastien TEINTURIER via bitcoin-dev wrote: > I'd like to propose a different way of looking at descendants that makes > it easier to design the new rules. The way I understand it, limiting the > impact on descendant transactions is only important for DoS protection, > not for incentive compatibility. I would argue that after evictions, > descendant transactions will be submitted again (because they represent > transactions that people actually want to make), I think that's backwards: we're trying to discourage people from wasting the network's bandwidth, which they would do by publishing transactions that will never get confirmed -- if they were to eventually get confirmed it wouldn't be a waste of bandwith, after all. But if the original descendent txs were that sort of spam, then they may well not be submitted again if the ancestor tx reaches a fee rate that's actually likely to confirm. I wonder sometimes if it could be sufficient to just have a relay rate limit and prioritise by ancestor feerate though. Maybe something like: - instead of adding txs to each peers setInventoryTxToSend immediately, set a mempool flag "relayed=false" - on a time delay, add the top N (by fee rate) "relayed=false" txs to each peer's setInventoryTxToSend and mark them as "relayed=true"; calculate how much kB those txs were, and do this again after SIZE/RATELIMIT seconds - don't include "relayed=false" txs when building blocks? - keep high-feerate evicted txs around for a while in case they get mined by someone else to improve compact block relay, a la the orphan pool? That way if the network is busy, any attempt to do low fee rate tx spam will just cause those txs to sit as relayed=false until they're replaced or the network becomes less busy and they're worth relaying. And your actual mempool accept policy can just be "is this tx a higher fee rate than the txs it replaces"... > Even if bitcoin core releases a new version with updated RBF rules, as a > wallet you'll need to keep using the old rules for a long time if you > want to be safe. All you need is for there to be *a* path that follows the new relay rules and gets from your node/wallet to perhaps 10% of hashpower, which seems like something wallet providers could construct relatively quickly? Cheers, aj