Re: [tor-dev] Better relay uptime visualisation

[Tim Wilson-Brown - teor <teor2345@xxxxxxxxx>]

On 8 Dec 2015, at 10:43, Tom Ritter <tom@xxxxxxxxx> wrote:

On 7 December 2015 at 13:51, Philipp Winter <phw@xxxxxxxxx> wrote:

I spent some time improving the existing relay uptime visualisation [0].
Inspired by a research paper [1], the new algorithm uses single-linkage
clustering with Pearson's correlation coefficient as distance function.
The idea is that relays are grouped next to each other if their uptime
(basically a binary sequence) is highly correlated.  Check out the
following gallery.  It contains monthly relay uptime images, dating back
to 2007:
<https://nymity.ch/sybilhunting/uptime-visualisation/>

If you aren't familiar with this type of visualisation: Every image
shows the uptime of all Tor relays that were online in a given month.
Every row is a consensus and every column is a relay.  White pixels mean
that a relay was offline and black pixels means that a relay was
online.  Red pixels are used to highlight suspiciously similar clusters.

That's really cool.  It seems to imply that the majority of the tor
network stop operating halfway through the month though... Do the
other tor graphs take into account hibernating relays?  For example, I
would expect the time-to-download graph would be somewhat affected:
https://metrics.torproject.org/torperf.html?graph=torperf&start=2015-10-01&end=2015-10-31&source=all&filesize=5mb

Hibernating relays run from the start of their first period to gauge load.

Then they start at a random time during the day/month, but early enough that they think they'll still use all their bandwidth.

I wonder if we're seeing another phenomenon? (daily / monthly server restarts?)

Or we could be seeing hibernation failing to work as intended.

Tim

Tim Wilson-Brown (teor)

teor2345 at gmail dot com
PGP 968F094B

teor at blah dot im
OTR CAD08081 9755866D 89E2A06F E3558B7F B5A9D14F

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