[tor-bugs] #20499 [Core Tor/Tor]: A running Tor won't update the microdesc consensus

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#20499: A running Tor won't update the microdesc consensus
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 Reporter:  rubiate       |          Owner:
     Type:  defect        |         Status:  new
 Priority:  High          |      Milestone:  Tor: 0.2.9.x-final
Component:  Core Tor/Tor  |        Version:  Tor: 0.2.9.4-alpha
 Severity:  Normal        |     Resolution:
 Keywords:  regression    |  Actual Points:
Parent ID:                |         Points:
 Reviewer:                |        Sponsor:
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Comment (by teor):

 Replying to [comment:16 nickm]:
 > So, if we're truly on exponential backoff, no maximum could be too
 large, right?

 Technically, yes.

 But at some exponent, the wait time becomes indistinguishable from
 failure.
 (Which is why we need to make sure requests trigger a new attempt.)

 I guess this essentially implements hibernate mode then?

 And we could just put the failure count up to something quite high, let's
 say, at most, the failure number at which tor is waiting for the average
 time between tor stable releases?

 > I also wonder, why are these failure counts so high?

 Firstly, because they get incremented twice for each failure.

 {{{
 download_status_increment_failure() gets called with a status_code of 304

 update_consensus_networkstatus_downloads() gets called again, this time it
 stops at the call to connection_dir_count_by_purpose_and_resource() which
 returns 1 (equal to max_in_progress_conns)

 download_status_increment_failure() gets called again, this time with a
 status_code of 0 (as a result each 304 response results in the fail count
 being increased by 2)
 }}}

 And secondly, because the laptop was offline for 12? hours?

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/20499#comment:17>
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