[tor-bugs] #3261 [Analysis]: Analyze how wrong our bridge usage statistics are

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#3261: Analyze how wrong our bridge usage statistics are
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 Reporter:  karsten   |          Owner:  karsten                
     Type:  project   |         Status:  assigned               
 Priority:  major     |      Milestone:  Sponsor F: July 1, 2012
Component:  Analysis  |        Version:                         
 Keywords:            |         Parent:                         
   Points:            |   Actualpoints:                         
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Comment(by karsten):

 Replying to [comment:8 arma]:
 > Weighting by uptime seconds seems like a weird approach. I have no idea
 what that ought to tell us.

 It's not a weird approach.  It's quite related to the approach that you
 suggested.

 Here's how the current approach works: assuming we have 10 bridges with 1,
 2, 3, ..., 10 hours uptime on a given day, and the 2-hours and the 4-hours
 bridge report statistics, the graph would show a fraction of bridges
 reporting statistics by uptime of (2+4)/(1+2+3+...+10).  Uptime is the
 time for which bridges report bandwidth histories here.

 If we switch to Tonga's reachability information, we have a similar
 statistic.  The only thing that changes is that we rely on Tonga telling
 us that the 1-hour bridge had the Running flag for 1 hours, the 2-hour
 bridge had it for 2 hours, and so on.  That will fix situations when
 bridges think they're available but Tonga disagrees.  But in theory,
 results should be quite similar or at least not totally off.  (Yay,
 theory.)

 > How much work is it to get to an answer to the question I ask above?

 I don't know.  Half a day or a day?  I want to make the analysis more
 precise by identifying reasons why bridges don't report statistics: less
 than 24 hours uptime, delay in descriptor publication (#4142), too old
 versions, no geoip file, etc.  I think that requires a rewrite of the
 analysis tool anyway, so I should be able to include Tonga's Running flag,
 too.

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/3261#comment:10>
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