Return-Path: Received: from silver.osuosl.org (smtp3.osuosl.org [140.211.166.136]) by lists.linuxfoundation.org (Postfix) with ESMTP id B2B79C0174 for ; Mon, 3 Feb 2020 03:41:33 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by silver.osuosl.org (Postfix) with ESMTP id A058420368 for ; Mon, 3 Feb 2020 03:41:33 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from silver.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id vTWJc-iCYRMd for ; Mon, 3 Feb 2020 03:41:32 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from mail.as397444.net (mail.as397444.net [69.59.18.99]) by silver.osuosl.org (Postfix) with ESMTPS id 6545620365 for ; Mon, 3 Feb 2020 03:41:32 +0000 (UTC) Received: from [69.59.18.158] (unknown [69.59.18.158]) by mail.as397444.net (Postfix) with ESMTPSA id 6174F191C4F; Mon, 3 Feb 2020 03:41:29 +0000 (UTC) Content-Type: multipart/alternative; boundary=Apple-Mail-DFCC224C-B9FA-44FD-A8CF-3959F09DF76A Content-Transfer-Encoding: 7bit From: Matt Corallo Mime-Version: 1.0 (1.0) Date: Sun, 2 Feb 2020 19:41:21 -0800 Message-Id: References: In-Reply-To: To: Anas , Bitcoin Protocol Discussion X-Mailer: iPhone Mail (17C54) Subject: Re: [bitcoin-dev] Characterizing orphan transaction in the Bitcoin network 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: Mon, 03 Feb 2020 03:41:33 -0000 --Apple-Mail-DFCC224C-B9FA-44FD-A8CF-3959F09DF76A Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable The orphan pool has nontrivial denial of service properties around transacti= on validation. In general, I think the goal has been to reduce/remove it, no= t the other way around. In any case, this is likely the wrong forum for soft= ware-level discussion of Bitcoin Core. For that, you probably want to open a= n issue on github.com/bitcoin/bitcoin. Matt > On Feb 1, 2020, at 14:12, Anas via bitcoin-dev wrote: >=20 > =EF=BB=BF > Hi all, >=20 > This paper - https://arxiv.org/pdf/1912.11541.pdf - characterizes orphan t= ransactions in the Bitcoin network and shows that increasing the size of the= orphan pool reduces network overhead with almost no additional performance o= verhead. What are your thoughts? >=20 > Abstract:=20 >> Orphan transactions are those whose parental income-sources are missing a= t the time that they are processed. These transactions are not propagated to= other nodes until all of their missing parents are received, and they thus e= nd up languishing in a local buffer until evicted or their parents are found= . Although there has been little work in the literature on characterizing th= e nature and impact of such orphans, it is intuitive that they may affect th= roughput on the Bitcoin network. This work thus seeks to methodically resear= ch such effects through a measurement campaign of orphan transactions on liv= e Bitcoin nodes. Our data show that, surprisingly, orphan transactions tend t= o have fewer parents on average than non-orphan transactions. Moreover, the s= alient features of their missing parents are a lower fee and larger size tha= n their non-orphan counterparts, resulting in a lower transaction fee per by= te. Finally, we note that the network overhead incurred by these orphan tran= sactions can be significant, exceeding 17% when using the default orphan mem= ory pool size (100 transactions). However, this overhead can be made negligi= ble, without significant computational or memory demands, if the pool size i= s merely increased to 1000 transactions. >=20 > Regards, > Anas > _______________________________________________ > bitcoin-dev mailing list > bitcoin-dev@lists.linuxfoundation.org > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev --Apple-Mail-DFCC224C-B9FA-44FD-A8CF-3959F09DF76A Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
The orphan pool has nontri= vial denial of service properties around transaction validation. In general,= I think the goal has been to reduce/remove it, not the other way around. In= any case, this is likely the wrong forum for software-level discussion of B= itcoin Core. For that, you probably want to open an issue on github.com/bitc= oin/bitcoin.

Matt

On Feb 1, 2020, at 14:12, Anas vi= a bitcoin-dev <bitcoin-dev@lists.linuxfoundation.org> wrote:

=EF=BB=BF
Hi all,

This paper - https://arxiv.org/pdf/1912.11541.pdf -&= nbsp;characterizes orphan transactions in the Bitcoin network and shows= that increasing the size of the orphan pool reduces network overhead with a= lmost no additional performance overhead. What are your thoughts?
=
Abstract: 
Orphan transactions a= re those whose parental income-sources are missing at the time that they are= processed. These transactions are not propagated to other nodes until all o= f their missing parents are received, and they thus end up languishing in a l= ocal buffer until evicted or their parents are found. Although there has bee= n little work in the literature on characterizing the nature and impact of s= uch orphans, it is intuitive that they may affect throughput on the Bitcoin n= etwork. This work thus seeks to methodically research such effects through a= measurement campaign of orphan transactions on live Bitcoin nodes. Our data= show that, surprisingly, orphan transactions tend to have fewer parents on a= verage than non-orphan transactions. Moreover, the salient features of their= missing parents are a lower fee and larger size than their non-orphan count= erparts, resulting in a lower transaction fee per byte. Finally, we note tha= t the network overhead incurred by these orphan transactions can be signific= ant, exceeding 17% when using the default orphan memory pool size (100 trans= actions). However, this overhead can be made negligible, without significant= computational or memory demands, if the pool size is merely increased to 10= 00 transactions.

Regards,
Anas
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