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 1Yysrq-0002LJ-30 for bitcoin-development@lists.sourceforge.net; Sun, 31 May 2015 02:20:50 +0000 Received-SPF: pass (sog-mx-2.v43.ch3.sourceforge.com: domain of gmail.com designates 74.125.82.49 as permitted sender) client-ip=74.125.82.49; envelope-from=pindar.wong@gmail.com; helo=mail-wg0-f49.google.com; Received: from mail-wg0-f49.google.com ([74.125.82.49]) by sog-mx-2.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1Yysro-0000bs-Ic for bitcoin-development@lists.sourceforge.net; Sun, 31 May 2015 02:20:50 +0000 Received: by wgez8 with SMTP id z8so89085203wge.0 for ; Sat, 30 May 2015 19:20:42 -0700 (PDT) MIME-Version: 1.0 X-Received: by 10.180.86.73 with SMTP id n9mr8487710wiz.78.1433038842628; Sat, 30 May 2015 19:20:42 -0700 (PDT) Received: by 10.194.156.226 with HTTP; Sat, 30 May 2015 19:20:42 -0700 (PDT) In-Reply-To: References: <554BE0E1.5030001@bluematt.me> Date: Sun, 31 May 2015 10:20:42 +0800 Message-ID: From: Pindar Wong To: Chun Wang <1240902@gmail.com> Content-Type: multipart/alternative; boundary=f46d0442806e2a0fe30517575b2c 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 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (pindar.wong[at]gmail.com) -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 X-Headers-End: 1Yysro-0000bs-Ic Cc: Bitcoin Dev 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 02:20:50 -0000 --f46d0442806e2a0fe30517575b2c Content-Type: text/plain; charset=UTF-8 Thank you very much Chun Wang for the details below. While I'm based in HK, but I'd like to propose that the miners in China work together with Gavin and others to run an experiment of sorts next month to gather more details for the community. p. On Sun, May 31, 2015 at 9:31 AM, 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 > --f46d0442806e2a0fe30517575b2c Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
Thank you very much Chun Wang for the details be= low.

While I'm based in HK, but I'd like to propose th= at the miners in China work together with Gavin and others to run an experi= ment of sorts next month to gather more details for the community.

<= /div>
p.




On Sun, May 31, 2015 at 9:31 AM, Chun Wang= <1240902@gmail.com> wrote:
On Sat, May 30, 2015 at 9:57 PM, Gavin Andresen <gavinandresen@gmail.com> wrot= e:
>> 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 fo= r
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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