[tor-bugs] #27066 [Core Tor/Tor]: circuit_build_times_update_alpha(): Bug: Could not determine largest build time

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#27066: circuit_build_times_update_alpha(): Bug: Could not determine largest build
time
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 Reporter:  cstest                     |          Owner:  (none)
     Type:  defect                     |         Status:  new
 Priority:  Medium                     |      Milestone:  Tor:
                                       |  0.3.5.x-final
Component:  Core Tor/Tor               |        Version:  Tor: 0.3.3.9
 Severity:  Normal                     |     Resolution:
 Keywords:  034-backport 033-backport  |  Actual Points:
Parent ID:                             |         Points:
 Reviewer:                             |        Sponsor:
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Comment (by mikeperry):

 After digging a bit more, I have to admit I'm still at a loss here as to
 the root cause. I have one last question: Did you see any log lines with
 "Tor has not observed any network activity"?

 In the meantime, I can do the following things in a new branch if you can
 run it in an environment that triggers the bug:

 1. Ensures that when that "Bug: Could not determine largest build times"
 line happens, we reset back to the default timeout and clear our timeout
 history.
 2. Emits log lines when Tor has decided not to build circuits.

 The first one should address your symptoms and allow v3 circuits to
 continue (I think), but the root cause of however we're mishandling v3
 circuit timeout record keeping will still be there.

 By itself, that first one may be something we want to backport anyway,
 since who knows what other deep mysteries surround CBT record keeping, or
 might in the future.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/27066#comment:8>
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