[tor-bugs] #28563 [Core Tor/sbws]: Work out how sbws can report excluded relays in the bandwidth file

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#28563: Work out how sbws can report excluded relays in the bandwidth file
-------------------------------------------------+-------------------------
 Reporter:  teor                                 |          Owner:  juga
     Type:  defect                               |         Status:
                                                 |  needs_review
 Priority:  Medium                               |      Milestone:  sbws:
                                                 |  1.1.0
Component:  Core Tor/sbws                        |        Version:
 Severity:  Normal                               |     Resolution:
 Keywords:  tor-bwauth, sbws-1.0-must-           |  Actual Points:
  moved-20181128, sbws-11x-final-                |
  removed-20190312, sbws-110-proposed, changes-  |
  version-minor                                  |
Parent ID:  #28547                               |         Points:
 Reviewer:  nickm                                |        Sponsor:
-------------------------------------------------+-------------------------

Comment (by teor):

 Replying to [comment:15 juga]:
 > Replying to [comment:14 teor]:
 >
 > > Tor ignores lines without a "bw=" key. But Tor 0.3.5 and later log an
 "Incomplete bandwidth file" warning for every incomplete line, every time
 they parse the file. That's not ok: we can not fill up authority operators
 logs with warnings.
 >
 > Sorry, i forgot about the warning.

 I only found out about the warning when I tested your design on an
 authority,

 > > Instead, you could use "bw=0 unmeasured=1 vote=0" and patch tor so
 that it ignores relay lines with "vote=0". Can you open another ticket for
 this Tor change?
 >
 > We have always say to do not give "bw=0" but "bw=1" because 0 can cause
 problems in Tor.
 > Shouldn't "bw=0" be "bw=1"?.

 Yes, I think 1 is better,

 > > Tor versions without the patch will give more 0 votes to unmeasured
 relays, so they will get lower bandwidth values in the consensus. That's
 ok.
 > >
 > > We might want to vote 0 for unmeasured relays in a future sbws or tor
 version.
 >
 > Hmm you mean to vote that the relay has 0 bandwidth?, right? (not to
 don't vote for the unmeasured relay).

 Vote 0 bandwidth for the relay. Or vote 1 bandwidth for the relay.

 > > That's why I added the "unmeasured=1" key. But it's not a change I
 want to make now, because you only have 10 paid days left. Can you open
 another ticket for this sbws change?

 What is the ticket number of the new ticket for the sbws change to vote on
 unmeasured relays?

 > Hmm, if i add "unmeasured=1" and make a Tor patch that ignores lines
 with "unmeasured=1", then we do not need to add "vote=0" and in a future
 Tor version we can still change Tor to vote on those lines, right?.

 We could p change Tor. But that takes 6-12 months from change to release
 to authority deployment.
 So I want to be able to change sbws.

 To make changing sbws easy, I want to separate reasons and actions.
 "unmeasured=1" is the reason, "vote=0" is the suggested action.
 In future, sbws might have more reasons, or sbws might suggest different
 actions.

 Replying to [comment:16 juga]:
 > Replying to [comment:14 teor]:
 >
 > > Instead, you could use "bw=0 unmeasured=1 vote=0" and patch tor so
 that it ignores relay lines with "vote=0". Can you open another ticket for
 this Tor change?

 What is the ticket number of the new ticket for the Tor patch to ignore
 vote=0?

 > Regarding the word "unmeasured", i'm not sure whether it should be named
 "excluded" or something similar, since maybe the relay was measured but
 excluded for some other reason.
 > I guess this word is not very important though.

 No, I mean "unmeasured", because that's the word we use in the consensus,
 when a relay doesn't have enough votes with measured bandwidths.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/28563#comment:22>
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