[tor-bugs] #28424 [Core Tor/Tor]: Refactor hs_service_callback() to no longer need to run once per second?

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#28424: Refactor hs_service_callback() to no longer need to run once per second?
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 Reporter:  nickm         |          Owner:  (none)
     Type:  defect        |         Status:  new
 Priority:  Medium        |      Milestone:  Tor: 0.4.0.x-final
Component:  Core Tor/Tor  |        Version:
 Severity:  Normal        |     Resolution:
 Keywords:                |  Actual Points:
Parent ID:                |         Points:
 Reviewer:                |        Sponsor:  Sponsor8-can
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Comment (by akwizgran):

 I updated the simulation to consider the probability of lookup failure as
 a function of time, and to use the same HSDirs in both hashrings. The new
 code is attached, along with graphs showing the mean and first percentile
 of the lookup success rate over 1000 independent runs.

 The first percentile gives an idea of the experience of an unlucky hidden
 service. The success rate for an unlucky service falls below 90% after 5
 hours, showing that the assessment in my last comment, based on mean time
 until possible failure, was too optimistic. Services do need to republish
 their descriptors frequently or there's a significant risk of lookup
 failure.

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/28424#comment:5>
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