Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191] helo=mx.sourceforge.net) by sfs-ml-2.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1Yz4Jo-0004mo-Ca for bitcoin-development@lists.sourceforge.net; Sun, 31 May 2015 14:34:28 +0000 Received-SPF: pass (sog-mx-1.v43.ch3.sourceforge.com: domain of coinapex.com designates 209.85.223.198 as permitted sender) client-ip=209.85.223.198; envelope-from=yifu@coinapex.com; helo=mail-ie0-f198.google.com; Received: from mail-ie0-f198.google.com ([209.85.223.198]) by sog-mx-1.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1Yz4Jn-0006PZ-3x for bitcoin-development@lists.sourceforge.net; Sun, 31 May 2015 14:34:28 +0000 Received: by iecxk8 with SMTP id xk8so193287423iec.3 for ; Sun, 31 May 2015 07:34:21 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to:cc:content-type; bh=JOSMxXXFlHK52BCoHGuOB5/a+j3j+0rHZu0FNhyh+4o=; b=C0j9k7LOaG2QNh/q50b8JgNjpZCZIReFVkwyZSynIvvYUtahCN08OPdBKWbPR+S5cb hrUTFEJVyU0dxMO5Zeijk5Rs0u0G5zXhOt25IVIGs7GB+fWw4U6m8zgyOzySqM5yGm5M XyQtMbHQWrFkVkUql2lidfj0FwPFGeTxRUo7QCyJ5fthrkpq9eNoWbXmTAINMnivfMIq xQjZ2E8OPfmf8gamfjhc6xJGyFXXZ7r0T+Z/v+ct7JkrGxJEemmfiQOZBFC+tdPNh2ZW Um+/lWvmPmwUSRcyNlymXZ3Pd5yZpLewGzj2mN0lYcgQRSt42sOvsMs523HBlSHouuDj B5RA== X-Gm-Message-State: ALoCoQm5e33r/P3Bo51X1mW7n3E77a3iM6mgdR4Bgr+FSxtd6KtjzGbItqWklfVw2pQ4F9RyfYfX MIME-Version: 1.0 X-Received: by 10.60.62.180 with SMTP id z20mr14815601oer.56.1433082861687; Sun, 31 May 2015 07:34:21 -0700 (PDT) Received: by 10.202.115.83 with HTTP; Sun, 31 May 2015 07:34:21 -0700 (PDT) In-Reply-To: References: <554BE0E1.5030001@bluematt.me> Date: Sun, 31 May 2015 10:34:21 -0400 Message-ID: From: Yifu Guo To: Chun Wang <1240902@gmail.com> Content-Type: multipart/alternative; boundary=001a11c21da6e7ad660517619aee X-Spam-Score: -0.6 (/) X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. -1.5 SPF_CHECK_PASS SPF reports sender host as permitted sender for sender-domain -0.0 SPF_PASS SPF: sender matches SPF record 1.0 HTML_MESSAGE BODY: HTML included in message -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature 0.0 LOTS_OF_MONEY Huge... sums of money -0.0 AWL AWL: Adjusted score from AWL reputation of From: address X-Headers-End: 1Yz4Jn-0006PZ-3x Cc: bitcoin-development@lists.sourceforge.net Subject: Re: [Bitcoin-development] Fwd: Block Size Increase Requirements 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: Sun, 31 May 2015 14:34:28 -0000 --001a11c21da6e7ad660517619aee Content-Type: text/plain; charset=UTF-8 I will abstain on this wrangle of "when", Instead I'd like to address some of the network topology health issues that's been brought up in this debate. Due to how blocks are being broadcast by miners at the moment, it is not difficult to find the origin node of these blocks. These more influential origin nodes are a minority, about <100 out of ~6000, <2%. These data points are important to certain attack vectors. It is highly recommended that pools adopt broadcast logic that rotates broadcasting nodes and increase their node count.. Eloipool has this implanted for those seeking to adopt/see it in action in the wild. China is a particular worse-case due to the sporadic nature of their internet infrastructure, especially connecting from/to outside of gfw, on a average node-walk I can get up to a 10% difference while I know for a fact some of the nodes shown to be down are up. In F2Pool's case, I see 6 replay nodes, I don't know if that's enough or that's all the nodes F2Pool runs, but it may be beneficial to set up multi-homing with shadowsocks over mptcp to increase the stability. also see if you can get a CERNET connection to be part of your rotations since their backbone is quite good. comments, question and grievances welcome. On Sat, May 30, 2015 at 9:31 PM, Chun Wang <1240902@gmail.com> wrote: > On Sat, May 30, 2015 at 9:57 PM, Gavin Andresen > wrote: > >> Bad miners could attack us and the network with artificial > >> big blocks. > > > > > > How? > > > > I ran some simulations, and I could not find a network topology where a > big > > miner producing big blocks could cause a loss of profit to another miner > > (big or small) producing smaller blocks: > > > > http://gavinandresen.ninja/are-bigger-blocks-better-for-bigger-miners > > > > (the 0.3% advantage I DID find was for the situation where EVERYBODY was > > producing big blocks). > > If someone propagate a 20MB block, it will take at best 6 seconds for > us to receive to verify it at current configuration, result of one > percent orphan rate increase. Or, we can mine the next block only on > the previous block's header, in this case, the network would see many > more transaction-less blocks. > > Our orphan rate is about 0.5% over the past few months. If the network > floods 20MB blocks, it can be well above 2%. Besides bandwidth, A 20MB > block could contain an average of 50000 transactions, hundred of > thousands of sigops, Do you have an estimate how long it takes on the > submitblock rpccall? > > For references, our 30Mbps bandwidth in Beijing costs us 1350 dollars > per month. We also use Aliyun and Linode cloud services for block > propagation. As of May 2015, the price is 0.13 U.S. dollars per GB for > 100Mbps connectivity at Aliyun. For a single cross-border TCP > connection, it would be certainly far slower than 12.5 MB/s. > > I think we can accept 5MB block at most. > > (sorry forgot to cc to the mailing list) > > > ------------------------------------------------------------------------------ > _______________________________________________ > Bitcoin-development mailing list > Bitcoin-development@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/bitcoin-development > -- *Yifu Guo* *"Life is an everlasting self-improvement."* --001a11c21da6e7ad660517619aee Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
I will abstai= n on this wrangle of "when",=C2=A0

I= nstead I'd like to address some of the network topology health issues t= hat's been brought up in this debate.

Due t= o how blocks are being broadcast by miners at the moment, it is not difficu= lt to find the origin node of these blocks. These more influential origin n= odes are a minority, about <100 out of ~6000, <2%. These data points = are important to certain attack vectors. It is highly recommended that pool= s adopt broadcast logic that rotates broadcasting nodes and increase their = node count.. Eloipool has this implanted for those seeking to adopt/see it = in action in the wild.
China is a particular wo= rse-case due to the sporadic nature of their internet infrastructure, espec= ially connecting from/to outside of gfw, on a average node-walk I can get u= p to a 10% difference while I know for a fact some of the nodes shown to be= down are up.

In F2Pool's case, I see 6 rep= lay nodes, I don't know if that's enough or that's all the node= s F2Pool runs, but it may be beneficial to set up multi-homing with shadows= ocks over mptcp to increase the stability. also see if you can get a CERNET= connection to be part of your rotations since their backbone is quite good= .

comments, question and=C2=A0grievances welcome.<= /div>

On Sat, May 30, 2015 at 9:31 PM, Chun Wang <1240902@gmail.com>= ; wrote:
On Sat, May 30, 2015 at 9= :57 PM, Gavin Andresen <gavin= andresen@gmail.com> wrote:
>> Bad miners could attack us and the network with artificial
>> big blocks.
>
>
> How?
>
> I ran some simulations, and I could not find a network topology where = a big
> miner producing big blocks could cause a loss of profit to another min= er
> (big or small) producing smaller blocks:
>
> http://gavinandresen.ninja/are-bigger-blocks-= better-for-bigger-miners
>
> (the 0.3% advantage I DID find was for the situation where EVERYBODY w= as
> producing big blocks).

If someone propagate a 20MB block, it will take at best 6 seconds for
us to receive to verify it at current configuration, result of one
percent orphan rate increase. Or, we can mine the next block only on
the previous block's header, in this case, the network would see many more transaction-less blocks.

Our orphan rate is about 0.5% over the past few months. If the network
floods 20MB blocks, it can be well above 2%. Besides bandwidth, A 20MB
block could contain an average of 50000 transactions, hundred of
thousands of sigops, Do you have an estimate how long it takes on the
submitblock rpccall?

For references, our 30Mbps bandwidth in Beijing costs us 1350 dollars
per month. We also use Aliyun and Linode cloud services for block
propagation. As of May 2015, the price is 0.13 U.S. dollars per GB for
100Mbps connectivity at Aliyun. For a single cross-border TCP
connection, it would be certainly far slower than 12.5 MB/s.

I think we can accept 5MB block at most.

(sorry forgot to cc to the mailing list)

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--
=
Yi= fu Guo
"Life is an everlasting self-improvement."
--001a11c21da6e7ad660517619aee--