[tor-dev] Better relay uptime visualisation
nusenu at openmailbox.org
Mon Dec 7 21:57:18 UTC 2015
> I spent some time improving the existing relay uptime visualisation .
> Inspired by a research paper , 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:
you can also spot
- all the daily hibernating relays roughly starting at the same time but
finishing their allocated amount of traffic at different times
- the 130 relays of the 11BX.. group.
(2015-10-30 - 2015-11-02)
> 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.
I assume they are highlighted only if they exceed a certain group size?
What is the threshold?
Until I looked at the heartbleed example I assumed grouping requires
"perfect matches" across the entire month but after seeing the
heartbleed example I'm not sure whether that is actually the case or if
two distinct groups are just next to each other and do not have a
"separator" between them.
> Another practical problem is that it's cumbersome to learn the relay
> fingerprint of a given column.
That would indeed make these graphs a lot more useful, but having a raw
time and group size alone would already be enough to look them up
indirectly - if that event is unique.
I would also find it useful to have it accept fingerprints as input and
graph their uptime to look at a given set of relays in certain cases
example input could be the fingerprints from + after these relays
have been around for some time.
Are you planing to generate these graphs on an ongoing basis?
-------------- next part --------------
A non-text attachment was scrubbed...
Size: 801 bytes
Desc: OpenPGP digital signature
More information about the tor-dev