[tor-bugs] #27146 [Core Tor/Tor]: Mismatched digest in 0.3.3.9 and master mixed chutney network

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#27146: Mismatched digest in 0.3.3.9 and master mixed chutney network
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 Reporter:  teor                                 |          Owner:  teor
     Type:  defect                               |         Status:
                                                 |  assigned
 Priority:  Very High                            |      Milestone:  Tor:
                                                 |  0.3.5.x-final
Component:  Core Tor/Tor                         |        Version:
 Severity:  Normal                               |     Resolution:
 Keywords:  regression, tor-dirauth, macOS,      |  Actual Points:
  035-must, 035-roadmap-proposed                 |
Parent ID:                                       |         Points:
 Reviewer:                                       |        Sponsor:
                                                 |  Sponsor8-can
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Comment (by teor):

 Replying to [comment:16 nickm]:
 > Teor, what did we decide for this one?  I think we thought that it was
 something to fix inside chutney for now, but I'm not sure I remember
 properly.

 This issue is part of a cluster of race conditions in the current
 dirvote_act() code.

 We reduced the frequency of the issue by increasing the consensus interval
 in chutney (#27300). On the public network, the timing required to trigger
 the race doesn't happen very often. And dirauth operators avoid these
 races by starting their machines outside the voting interval hh:50-hh:00.

 I'd like to revise my bug27146-034 branch to solve this issue. But we need
 better tests to work out if we've solved it or not.

 I opened #28036 so we can test dirvote_act() inside a dirauth instance. If
 we write failed votes, signatures, and consensuses to disk (#20625 and
 #4539), then it would be a lot easier to diagnose these issues.

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/27146#comment:18>
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