[tor-bugs] #28042 [Core Tor/sbws]: Restrictions on the number of minimum measurements to include a relay in the bandwidth file give very few relays

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#28042: Restrictions on the number of minimum measurements to include a relay in
the bandwidth file give very few relays
---------------------------+-------------------------------------
 Reporter:  juga           |          Owner:  (none)
     Type:  defect         |         Status:  new
 Priority:  Medium         |      Milestone:  sbws 1.0 (MVP nice)
Component:  Core Tor/sbws  |        Version:
 Severity:  Normal         |     Resolution:
 Keywords:                 |  Actual Points:
Parent ID:                 |         Points:
 Reviewer:                 |        Sponsor:
---------------------------+-------------------------------------

Comment (by pastly):

 Replying to [comment:2 teor]:
 > Replying to [ticket:28042 juga]:
 > > In #27338##comment:6, teor suggested:
 > >
 > > > If any of these things are true, do not put the relay in the
 bandwidth file:
 > > > * there are less than 2 sbws measured bandwidths
 > > > * all the sbws measured bandwidths are within 24 hours of each other
 > >
 > > With these restrictions and the current data, the number of relays to
 be included in the bandwidth file is only 242.
 > > Removing 1st restriction (ie, min num measurements: 1), there're 5209
 relays
 > > Incrementing the number of hours between each other to 3d, doesn't
 give any relays
 > > Decrementing the number of hours between each other to 12h, gives 302
 relays
 > >
 > > So:
 > > 1. we should check prioritization, in case we're not doing it
 correctly, probably should open a new ticket for that
 >
 > If sbws' current prioritisation rule says "stop when there is 1
 measurement", we need to change it to "stop when there are 2 measurements
 that are at least 24 hours apart".

 It doesn't. It is min-priority queue where priority is based on how
 recently a relay's measurements were made.
 [https://github.com/torproject/sbws/blob/8f4c5b8a8e775165810b188663e489e8ac91d050/sbws/lib/relayprioritizer.py#L26
 Read more here].

 sbws never "stops."

 It would be fair to say sbws prioritizes getting 1 measurement for each
 relay, then 2 measurements, then 3, then 4...

 For further explaination about the prioritizer,
 [https://trac.torproject.org/projects/tor/ticket/28061#comment:2 see my
 comment on #28042]

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/28042#comment:3>
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