1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
|
Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191]
helo=mx.sourceforge.net)
by sfs-ml-3.v29.ch3.sourceforge.com with esmtp (Exim 4.76)
(envelope-from <jgarzik@bitpay.com>) id 1YsGWR-0002QA-9k
for bitcoin-development@lists.sourceforge.net;
Tue, 12 May 2015 20:11:23 +0000
Received-SPF: pass (sog-mx-1.v43.ch3.sourceforge.com: domain of bitpay.com
designates 209.85.218.44 as permitted sender)
client-ip=209.85.218.44; envelope-from=jgarzik@bitpay.com;
helo=mail-oi0-f44.google.com;
Received: from mail-oi0-f44.google.com ([209.85.218.44])
by sog-mx-1.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128)
(Exim 4.76) id 1YsGWQ-0001eV-64
for bitcoin-development@lists.sourceforge.net;
Tue, 12 May 2015 20:11:23 +0000
Received: by oign205 with SMTP id n205so15199050oig.2
for <bitcoin-development@lists.sourceforge.net>;
Tue, 12 May 2015 13:11:16 -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:from:date
:message-id:subject:to:cc:content-type;
bh=6rigav3kInpRoKNJPALSWr8VvYIvgGWoZvOWcdZ45Lg=;
b=ZP71Nj0MpxOKU0S5ldIwTo4PAYiMtge2oKGC142Gi1sVacSu1CT4/aJWQahGDFrpND
EMDi8F6jyVdmTtqJnu6U2dG4aBjA9tiurFofbkFr/udypRb+gzpB1wSP4K7usDwmX9Uy
YD/u9QirS5OlYMXZIbERX/krr5ENJQnbqxDGD4xAHKdU4LCHeNQjo1Cjv2qfUFx/9w0f
0VIcuD4kyx66NgJnBs8YOLMph5gJwpWshelARvfrUvQ/uQZylpYC6mbKT2pu3/uJj0i7
n6/FUlXlc9HwdhiecPo3WEfPVgYSCvX5xWnzArmEuSKqDh5IcDCv/SJQLZho0x1MqwaO
tWsQ==
X-Gm-Message-State: ALoCoQlupvx4j0oNNl324J56jmUuhFwfUotnqtT8xzvai1r8ieRc1KF3jZcgwtNfrwhy5O3w3uR1
X-Received: by 10.182.86.9 with SMTP id l9mr4408179obz.61.1431461476536; Tue,
12 May 2015 13:11:16 -0700 (PDT)
MIME-Version: 1.0
Received: by 10.202.108.149 with HTTP; Tue, 12 May 2015 13:10:56 -0700 (PDT)
In-Reply-To: <CAAS2fgTCMeNdcmMxURxaoAJn8=XZnTP8Gp6PbRk5w7KXAZ8t3g@mail.gmail.com>
References: <CANJO25J1WRHtfQLVXUB2s_sjj39pTPWmixAcXNJ3t-5os8RPmQ@mail.gmail.com>
<CANJO25JTtfmfsOQYOzJeksJn3CoKE3W8iLGsRko-_xd4XhB3ZA@mail.gmail.com>
<CAJHLa0O5OxaX5g3u=dnCY6Lz_gK3QZgQEPNcWNVRD4JziwAmvg@mail.gmail.com>
<20150512171640.GA32606@savin.petertodd.org>
<CAE-z3OV3VdSoiTSfASwYHr1CjZSqio303sqGq_1Y9yaYgov2sw@mail.gmail.com>
<CAAS2fgRzGkcJbWbJmFN2-NSJGUcLdPKp0q7FjM0x7WDvHoRq=g@mail.gmail.com>
<CANJO25+qURmDzsMgnm7+tsw7icFO--gWhmKmQPuNQCoh_R2big@mail.gmail.com>
<CAJHLa0PDbxuqRHuGNhsyvLpAaDq=ZHSg_u-Sb7FqNVnYrhFkFg@mail.gmail.com>
<CAAS2fgTCMeNdcmMxURxaoAJn8=XZnTP8Gp6PbRk5w7KXAZ8t3g@mail.gmail.com>
From: Jeff Garzik <jgarzik@bitpay.com>
Date: Tue, 12 May 2015 13:10:56 -0700
Message-ID: <CAJHLa0O3fgmg4AFAM9+4RRkhSo8ekATs2Ks+Ry7ooQafjQ-4qw@mail.gmail.com>
To: Gregory Maxwell <gmaxwell@gmail.com>
Content-Type: multipart/alternative; boundary=089e014954c8d1a48f0515e818f8
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
X-Headers-End: 1YsGWQ-0001eV-64
Cc: Bitcoin Dev <bitcoin-development@lists.sourceforge.net>
Subject: Re: [Bitcoin-development] Proposed additional options for pruned
nodes
X-BeenThere: bitcoin-development@lists.sourceforge.net
X-Mailman-Version: 2.1.9
Precedence: list
List-Id: <bitcoin-development.lists.sourceforge.net>
List-Unsubscribe: <https://lists.sourceforge.net/lists/listinfo/bitcoin-development>,
<mailto:bitcoin-development-request@lists.sourceforge.net?subject=unsubscribe>
List-Archive: <http://sourceforge.net/mailarchive/forum.php?forum_name=bitcoin-development>
List-Post: <mailto:bitcoin-development@lists.sourceforge.net>
List-Help: <mailto:bitcoin-development-request@lists.sourceforge.net?subject=help>
List-Subscribe: <https://lists.sourceforge.net/lists/listinfo/bitcoin-development>,
<mailto:bitcoin-development-request@lists.sourceforge.net?subject=subscribe>
X-List-Received-Date: Tue, 12 May 2015 20:11:23 -0000
--089e014954c8d1a48f0515e818f8
Content-Type: text/plain; charset=UTF-8
True. Part of the issue rests on the block sync horizon/cliff. There is a
value X which is the average number of blocks the 90th percentile of nodes
need in order to sync. It is sufficient for the [semi-]pruned nodes to
keep X blocks, after which nodes must fall back to archive nodes for older
data.
There is simply far, far more demand for recent blocks, and the demand for
old blocks very rapidly falls off.
There was even a more radical suggestion years ago - refuse to sync if too
old (>2 weeks?), and force the user to download ancient data via torrent.
On Tue, May 12, 2015 at 1:02 PM, Gregory Maxwell <gmaxwell@gmail.com> wrote:
> On Tue, May 12, 2015 at 7:38 PM, Jeff Garzik <jgarzik@bitpay.com> wrote:
> > One general problem is that security is weakened when an attacker can
> DoS a
> > small part of the chain by DoS'ing a small number of nodes - yet the
> impact
> > is a network-wide DoS because nobody can complete a sync.
>
> It might be more interesting to think of that attack as a bandwidth
> exhaustion DOS attack on the archive nodes... if you can't get a copy
> without them, thats where you'll go.
>
> So the question arises: does the option make some nodes that would
> have been archive not be? Probably some-- but would it do so much that
> it would offset the gain of additional copies of the data when those
> attacks are not going no. I suspect not.
>
> It's also useful to give people incremental ways to participate even
> when they can't swollow the whole pill; or choose to provide the
> resource thats cheap for them to provide. In particular, if there is
> only two kinds of full nodes-- archive and pruned; then the archive
> nodes take both a huge disk and bandwidth cost; where as if there are
> fractional then archives take low(er) bandwidth unless the fractionals
> get DOS attacked.
>
--
Jeff Garzik
Bitcoin core developer and open source evangelist
BitPay, Inc. https://bitpay.com/
--089e014954c8d1a48f0515e818f8
Content-Type: text/html; charset=UTF-8
Content-Transfer-Encoding: quoted-printable
<div dir=3D"ltr">True.=C2=A0 Part of the issue rests on the block sync hori=
zon/cliff.=C2=A0 There is a value X which is the average number of blocks t=
he 90th percentile of nodes need in order to sync.=C2=A0 It is sufficient f=
or the [semi-]pruned nodes to keep X blocks, after which nodes must fall ba=
ck to archive nodes for older data.<div><br></div><div>There is simply far,=
far more demand for recent blocks, and the demand for old blocks very rapi=
dly falls off.<br><div><br></div><div>There was even a more radical suggest=
ion years ago - refuse to sync if too old (>2 weeks?), and force the use=
r to download ancient data via torrent.</div><div><br></div><div><br></div>=
</div></div><div class=3D"gmail_extra"><br><div class=3D"gmail_quote">On Tu=
e, May 12, 2015 at 1:02 PM, Gregory Maxwell <span dir=3D"ltr"><<a href=
=3D"mailto:gmaxwell@gmail.com" target=3D"_blank">gmaxwell@gmail.com</a>>=
</span> wrote:<br><blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .=
8ex;border-left:1px #ccc solid;padding-left:1ex"><span class=3D"">On Tue, M=
ay 12, 2015 at 7:38 PM, Jeff Garzik <<a href=3D"mailto:jgarzik@bitpay.co=
m">jgarzik@bitpay.com</a>> wrote:<br>
> One general problem is that security is weakened when an attacker can =
DoS a<br>
> small part of the chain by DoS'ing a small number of nodes - yet t=
he impact<br>
> is a network-wide DoS because nobody can complete a sync.<br>
<br>
</span>It might be more interesting to think of that attack as a bandwidth<=
br>
exhaustion DOS attack on the archive nodes... if you can't get a copy<b=
r>
without them, thats where you'll go.<br>
<br>
So the question arises: does the option make some nodes that would<br>
have been archive not be? Probably some-- but would it do so much that<br>
it would offset the gain of additional copies of the data when those<br>
attacks are not going no. I suspect not.<br>
<br>
It's also useful to give people incremental ways to participate even<br=
>
when they can't swollow the whole pill; or choose to provide the<br>
resource thats cheap for them to provide.=C2=A0 In particular, if there is<=
br>
only two kinds of full nodes-- archive and pruned; then the archive<br>
nodes take both a huge disk and bandwidth cost; where as if there are<br>
fractional then archives take low(er) bandwidth unless the fractionals<br>
get DOS attacked.<br>
</blockquote></div><br><br clear=3D"all"><div><br></div>-- <br><div class=
=3D"gmail_signature">Jeff Garzik<br>Bitcoin core developer and open source =
evangelist<br>BitPay, Inc. =C2=A0 =C2=A0 =C2=A0<a href=3D"https://bitpay.co=
m/" target=3D"_blank">https://bitpay.com/</a></div>
</div>
--089e014954c8d1a48f0515e818f8--
|
