[tor-bugs] #27135 [Core Tor/sbws]: Write descriptor bandwidths average in raw results

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#27135: Write descriptor bandwidths average in raw results
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 Reporter:  juga           |          Owner:  juga
     Type:  defect         |         Status:  assigned
 Priority:  Medium         |      Milestone:  sbws 1.0 (MVP must)
Component:  Core Tor/sbws  |        Version:
 Severity:  Normal         |     Resolution:
 Keywords:                 |  Actual Points:
Parent ID:  #27108         |         Points:
 Reviewer:                 |        Sponsor:
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Comment (by teor):

 Replying to [comment:17 juga]:
 > Taking the descriptor observed bandwidth only when the relay is measured
 and calculating the mean when there're several observed bandwidth values
 for the same relay, the graph is now very close to torflow, with data from
 only 1 day.

 That's great news!
 Thank you (and pastly) for all your hard work.

 > Should i still take the observed bandwidth every hour and calculate the
 mean and/or decaying average?

 If the simple method works, then let's keep it simple.

 How long do you keep old relay bandwidths before deleting them?
 I suggest 1 week is a good time.

 Next steps:

 How should we deal with differences between sbws and torflow?

 Here are some example rules:
 1. Any difference between sbws and torflow is a bug in sbws that should be
 fixed
 2. If a sbws deployment is within 50% of any existing bandwidth authority,
 sbws is ok (the existing bandwidth authorities are within 50% of each
 other)
 3. Let's choose an ideal bandwidth distribution for the Tor network, and
 modify sbws until we get that distribution

 I suggest we use 2 as a transition rule, and 3 as a long-term rule.
 (Before we do rule 3 designs, we will need more research.)

 Which mode do you think should be the default?
 1. Ignore self-reported bandwidth, so sbws can be more secure (and then
 scale linearly)
 2. Use observed bandwidth to scale measurements, so sbws can be more like
 torflow

 I think we should ask the bandwidth authority operators and network team
 for feedback, so we can answer both these questions.

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/27135#comment:18>
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