To: Jonas Schnelli <dev@jonasschnelli.ch>, Luke Dashjr <luke@dashjr.org>
References: <E1313B4E-6061-49CA-9E8C-E5FD468531C0@jonasschnelli.ch>
	<201705111924.22055.luke@dashjr.org>
	<61C68F26-AD36-4AB4-A065-020BD549CEBC@jonasschnelli.ch>
From: Aymeric Vitte <vitteaymeric@gmail.com>
Message-ID: <f0417e14-fb2c-3572-f8e9-06c7adbf3d2b@gmail.com>
Date: Thu, 11 May 2017 22:36:33 +0200
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Cc: bitcoin-dev@lists.linuxfoundation.org
Subject: Re: [bitcoin-dev] BIP proposal: NODE_NETWORK_LIMITED service bits
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Sorry again, is this discussion really serious?

In this thread, previous ones or others, the level of approximation is
obvious, often shadowed by useless maths/papers and strange calculations
that are not helping, at the end nobody knows what would happen "if",
how far the chain can roll back, etc

Then don't make pruning the default if it's the current concern, pruning
is of no use

Again, the priority should be to scale the full nodes


Le 11/05/2017 =E0 22:10, Jonas Schnelli via bitcoin-dev a =E9crit :
>> Is 49 days particularly useful? Would it be a problem to instead leave=
 both-
>> bits undefined? I'm thinking this might be better as a way to indicate=
 "7
>> days, plus a deterministically chosen set of historical blocks"=85
> I though two service bits allow three states and we should define all t=
hree combinations.
> But I guess an adequate =84definition=93 would be to reserve it for fut=
ure =84definitions=93.
> Or use Gregory's proposal of min 2016*2 blocks & keep it =84undefined=93=
 for now.
>
> 49 days was chosen to allow SPV peers to be =84offline=93 for a month a=
nd still be capable to catch-up with a peer pruned to a datadir of ~10GB.=

>
>> This is technically true right now, but as soon as segwit activates, i=
t will
>> no longer be... Therefore, I suggest striking it from the BIP, expound=
ing on
>> it in greater detail, or making it true for the longer term.
> AFAIK Core does also guaranteed the 288 blocks post segwit activation:
> https://github.com/bitcoin/bitcoin/blob/08a7316c144f9f2516db8fa62400893=
f4358c5ae/src/validation.h#L204
> But maybe I=92m confused.
>
>>> Peers following this BIP SHOULD connect a limited amount of their ava=
ilable
>>> outbound connections to peers signaling one or both of the
>>> NODE_NETWORK_LIMITED_* service bits if they expect to request less bl=
ocks
>>> than the signaled number.
>> This isn't entirely clear whether it refers to peers downloading block=
s, or
>> peers serving them. (I assume the former, but it should be clarified.)=

> Indeed. I=92ll try to make that more clear.
>
>>> Light clients (and such) who are not checking the nServiceFlags (serv=
ice
>>> bits) from a relayed addr-message may unwillingly connect to a pruned=
 peer
>>> and ask for (filtered) blocks at a depth below their pruned depth.
>> Wouldn't this already be a problem, without the BIP?
> AFAIK, Core does currently only relay NODE_NETWORK addresses.
> But yes, It may be a problem already.
>
> </jonas>
>
>
>
> _______________________________________________
> bitcoin-dev mailing list
> bitcoin-dev@lists.linuxfoundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev

--=20
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Check the 10 M passwords list: http://peersm.com/findmyass
Anti-spies and private torrents, dynamic blocklist: http://torrent-live.o=
rg
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node-Tor : https://www.github.com/Ayms/node-Tor
GitHub : https://www.github.com/Ayms


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    <p>Sorry again, is this discussion really serious?</p>
    <p>In this thread, previous ones or others, the level of
      approximation is obvious, often shadowed by useless maths/papers
      and strange calculations that are not helping, at the end nobody
      knows what would happen "if", how far the chain can roll back, etc<br>
    </p>
    <p>Then don't make pruning the default if it's the current concern,
      pruning is of no use</p>
    <p>Again, the priority should be to scale the full nodes<br>
    </p>
    <br>
    <div class="moz-cite-prefix">Le 11/05/2017 à 22:10, Jonas Schnelli
      via bitcoin-dev a écrit :<br>
    </div>
    <blockquote
      cite="mid:61C68F26-AD36-4AB4-A065-020BD549CEBC@jonasschnelli.ch"
      type="cite">
      <pre wrap="">
</pre>
      <blockquote type="cite">
        <pre wrap="">Is 49 days particularly useful? Would it be a problem to instead leave both-
bits undefined? I'm thinking this might be better as a way to indicate "7
days, plus a deterministically chosen set of historical blocks"…
</pre>
      </blockquote>
      <pre wrap="">
I though two service bits allow three states and we should define all three combinations.
But I guess an adequate „definition“ would be to reserve it for future „definitions“.
Or use Gregory's proposal of min 2016*2 blocks &amp; keep it „undefined“ for now.

49 days was chosen to allow SPV peers to be „offline“ for a month and still be capable to catch-up with a peer pruned to a datadir of ~10GB.

</pre>
      <blockquote type="cite">
        <pre wrap="">
This is technically true right now, but as soon as segwit activates, it will
no longer be... Therefore, I suggest striking it from the BIP, expounding on
it in greater detail, or making it true for the longer term.
</pre>
      </blockquote>
      <pre wrap="">
AFAIK Core does also guaranteed the 288 blocks post segwit activation:
<a class="moz-txt-link-freetext" href="https://github.com/bitcoin/bitcoin/blob/08a7316c144f9f2516db8fa62400893f4358c5ae/src/validation.h#L204">https://github.com/bitcoin/bitcoin/blob/08a7316c144f9f2516db8fa62400893f4358c5ae/src/validation.h#L204</a>
But maybe I’m confused.

</pre>
      <blockquote type="cite">
        <pre wrap="">
</pre>
        <blockquote type="cite">
          <pre wrap="">Peers following this BIP SHOULD connect a limited amount of their available
outbound connections to peers signaling one or both of the
NODE_NETWORK_LIMITED_* service bits if they expect to request less blocks
than the signaled number.
</pre>
        </blockquote>
        <pre wrap="">
This isn't entirely clear whether it refers to peers downloading blocks, or
peers serving them. (I assume the former, but it should be clarified.)
</pre>
      </blockquote>
      <pre wrap="">
Indeed. I’ll try to make that more clear.

</pre>
      <blockquote type="cite">
        <pre wrap="">
</pre>
        <blockquote type="cite">
          <pre wrap="">Light clients (and such) who are not checking the nServiceFlags (service
bits) from a relayed addr-message may unwillingly connect to a pruned peer
and ask for (filtered) blocks at a depth below their pruned depth.
</pre>
        </blockquote>
        <pre wrap="">
Wouldn't this already be a problem, without the BIP?
</pre>
      </blockquote>
      <pre wrap="">
AFAIK, Core does currently only relay NODE_NETWORK addresses.
But yes, It may be a problem already.

&lt;/jonas&gt;

</pre>
      <br>
      <fieldset class="mimeAttachmentHeader"></fieldset>
      <br>
      <pre wrap="">_______________________________________________
bitcoin-dev mailing list
<a class="moz-txt-link-abbreviated" href="mailto:bitcoin-dev@lists.linuxfoundation.org">bitcoin-dev@lists.linuxfoundation.org</a>
<a class="moz-txt-link-freetext" href="https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev">https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev</a>
</pre>
    </blockquote>
    <br>
    <pre class="moz-signature" cols="72">-- 
Zcash wallets made simple: <a class="moz-txt-link-freetext" href="https://github.com/Ayms/zcash-wallets">https://github.com/Ayms/zcash-wallets</a>
Bitcoin wallets made simple: <a class="moz-txt-link-freetext" href="https://github.com/Ayms/bitcoin-wallets">https://github.com/Ayms/bitcoin-wallets</a>
Get the torrent dynamic blocklist: <a class="moz-txt-link-freetext" href="http://peersm.com/getblocklist">http://peersm.com/getblocklist</a>
Check the 10 M passwords list: <a class="moz-txt-link-freetext" href="http://peersm.com/findmyass">http://peersm.com/findmyass</a>
Anti-spies and private torrents, dynamic blocklist: <a class="moz-txt-link-freetext" href="http://torrent-live.org">http://torrent-live.org</a>
Peersm : <a class="moz-txt-link-freetext" href="http://www.peersm.com">http://www.peersm.com</a>
torrent-live: <a class="moz-txt-link-freetext" href="https://github.com/Ayms/torrent-live">https://github.com/Ayms/torrent-live</a>
node-Tor : <a class="moz-txt-link-freetext" href="https://www.github.com/Ayms/node-Tor">https://www.github.com/Ayms/node-Tor</a>
GitHub : <a class="moz-txt-link-freetext" href="https://www.github.com/Ayms">https://www.github.com/Ayms</a></pre>
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