[tor-bugs] #3277 [Analysis]: Analyze how long after earning the HSDir flag relays go away

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#3277: Analyze how long after earning the HSDir flag relays go away
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 Reporter:  karsten   |          Owner:     
     Type:  task      |         Status:  new
 Priority:  normal    |      Milestone:     
Component:  Analysis  |        Version:     
 Keywords:            |         Parent:     
   Points:            |   Actualpoints:     
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Comment(by karsten):

 Replying to [comment:2 Sebastian]:
 > These results are very interesting. They seem to show bug 1810, because
 after 24+18 hours there's another big drop in relay availability, [...]

 Note that the graph shows HSDir sessions between May 2010 and April 2011.
 Not sure how much these are affected by #1810.

 > [...] and they also seem to indicate that the move to 25 hours was a
 good idea.

 Actually, the drop from 0 to 1 hours doesn't look that unusual.  I
 attached another graph that contains "simulations" of assigning flags
 after 25 and 26 hours.  The idea of the simulations is simply to remove
 all 0-hour sessions (all 0-hour and 1-hour sessions) and subtract 1 hour
 (2 hours) from all other sessions.  As you can see, the drop from 0 to 1
 hour is still around 8 % (7 %).  Of course, this comes at the cost of
 having a smaller set of relays with the HSDir flag.  So, it might have
 been a good idea to change the requirement to 25 hours, but I think this
 needs more analysis.

 > I'm not exactly sure how the timings work out, I believe if you were
 reachable at :15 but not at :30 or :45, you still get into the consensus
 (I think there's a separate bug about that).

 Okay.  If there's such a bug, it might be relevant for interpreting the
 results.  But I'm afraid we can't make the analysis more precise, because
 the only data we have are the consensuses.

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/3277#comment:3>
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