[tor-bugs] #2550 [Torflow]: bwauth should reschedule quicker bandwidth test when bandwidthrate changes?

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#2550: bwauth should reschedule quicker bandwidth test when bandwidthrate changes?
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 Reporter:  arma         |          Owner:  mikeperry
     Type:  enhancement  |         Status:  new      
 Priority:  normal       |      Milestone:           
Component:  Torflow      |        Version:           
 Keywords:               |         Parent:           
   Points:  ?            |   Actualpoints:           
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Comment(by mikeperry):

 Option 1 might work. We might be able to add logic to schedule a quick
 test as soon as we noticed that a descriptor has changed advertised
 bandwidth values significantly. This could create a situation where a
 relay could cause the bw scanners to make no progress though, if we reset
 what we have when we do this.. But if we don't discard, we'll have
 inaccurate results..

 Option 2 is technically what we already do now: We use the previous
 consensus descriptor value to multiply the measured ratio against. It is
 possible this is not optimal because we don't fetch often enough, and need
 to set torrc options FetchDirInfoExtraEarly and FetchDirInfoEarly.

 It is also possible that we are actually measuring a low ratio on some bw
 auths and a high ratio on others, just based on when we measure. Depending
 on if the relay is actually rate limiting, or just altering
 MaxAdvertisedBandwidth, the ratio we get could be either super low while
 the relay reports a low value, or super high...

 Option 3 is unlikely to work out if the bandwidthrate change is too
 frequent.. We are not likely to gather measurements for all values.

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/2550#comment:4>
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