Opened 7 years ago

Closed 22 months ago

#6466 closed task (wontfix)

Analyze entropy graphs

Reported by: asn Owned by:
Priority: Medium Milestone:
Component: Metrics/Analysis Version:
Severity: Keywords:
Cc: Actual Points:
Parent ID: #6232 Points:
Reviewer: Sponsor:

Description

#6232 resulted in some graphs of the "diversity" of the network over time based on the entropy of the bandwidth weights.

This ticket is responsible for analyzing these graphs, figuring out which are useful, how they can be improved, and how they can be used.

Child Tickets

Change History (3)

comment:1 Changed 7 years ago by asn

Some things to notice in attachment:entropy-2012-07-25.png:ticket:6232:

  • Looking at All relays, we see that during the four years of 2009-2012, the number of relays increased a lot (1300~ relays in 2009, 3000~ relays in 2012) but the entropy of bw weights is pretty much the same.

This means that both the Tor network of 2009 and the current Tor network are supposedly equal to a fair network of 28.2 = 300~ relays.

The All guards graph seems to be in a better shape in 2012 than in 2009; the opposite is true for All exits.

  • There was a big drop right before 2010 and it took the network around a year to recover from it (looking at all relays and all guards the network recovered around 2011). What is that?
  • Looking at All relays, we see that right after 2010 there was a drop in the maximum entropy (that is, some relays disappeared) which resulted in a big spike in the bw weights entropy.

Also, in the middle of 2010 there is a small spike in maximum entropy which seems to result in a spike in the bw weights entropy too.

comment:2 in reply to:  1 Changed 7 years ago by arma

Replying to asn:

  • There was a big drop right before 2010 and it took the network around a year to recover from it (looking at all relays and all guards the network recovered around 2011). What is that?

It corresponds to the first time we turned on the bwauths for real:
https://metrics.torproject.org/performance.html?graph=torperf&start=2009-01-01&end=2012-07-26&source=all&filesize=50kb#torperf

Then the blips of increased entropy we see are when the bwauths are off briefly.

comment:3 Changed 22 months ago by karsten

Resolution: wontfix
Status: newclosed

Closing tickets in Metrics/Analysis that have been created 5+ years ago and not seen progress recently, except for the ones that "nickm-cares" about.

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