[tor-bugs] #24456 [Core Tor/Tor]: Figure out what to do with the guardfraction feature

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#24456: Figure out what to do with the guardfraction feature
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 Reporter:  asn                                  |          Owner:  (none)
     Type:  defect                               |         Status:
                                                 |  needs_review
 Priority:  Medium                               |      Milestone:  Tor:
                                                 |  0.3.3.x-final
Component:  Core Tor/Tor                         |        Version:
 Severity:  Normal                               |     Resolution:
 Keywords:  tor-dirauth, tor-guard, review-      |  Actual Points:
  group-32, review-group-33, review-group-34,    |
  033-triage-20180320, 033-included-20180320     |
Parent ID:                                       |         Points:  2
 Reviewer:  mikeperry                            |        Sponsor:
-------------------------------------------------+-------------------------

Comment (by mikeperry):

 Replying to [comment:21 teor]:
 > If mike is correct, and the guardfraction code isolated and won't
 require maintenance effort, we can remove the code now, and "git revert"
 that commit later.
 >
 > If a revert won't work later, then the code does actually require
 maintainence effort.

 Having maintained a fork before, I can say that this is not true. Diffs
 that are otherwise untouched can be broken simply by modifying or
 relocating surrounding but unrelated lines.

 In particular, this code touches the consensus weights. When we update
 these weights for padding in #8453, it will be much easier to avoid making
 changes that would break or simply conflict with this code if it is right
 there where we can see it. When we perform those padding updates (and
 other consensus changes), we're likely to want to have a testing
 framework, which will make verifying the fix in #16255 easier as well.

 If we take the minimum change here (ie asn/bug24456_032), the OBSOLETE
 macro will cause these config entries to be ignored, so that as soon as it
 is deployed, dirauths will stop reading the guardfraction files
 automatically.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/24456#comment:25>
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