[metrics-bugs] #31422 [Circumvention/BridgeDB]: Make BridgeDB report internal metrics

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#31422: Make BridgeDB report internal metrics
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 Reporter:  phw                                  |          Owner:  phw
     Type:  enhancement                          |         Status:
                                                 |  needs_information
 Priority:  Medium                               |      Milestone:
Component:  Circumvention/BridgeDB               |        Version:
 Severity:  Normal                               |     Resolution:
 Keywords:  s30-o21a1, anti-censorship-          |  Actual Points:
  roadmap-2020                                   |
Parent ID:  #31274                               |         Points:  2
 Reviewer:  agix                                 |        Sponsor:
                                                 |  Sponsor30-can
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Comment (by karsten):

 Replying to [comment:18 phw]:
 > Thanks for the feedback! I removed the standard deviation and added the
 four metrics you suggest: 1st and 3rd quartile, and the upper and lower
 whiskers.
 [https://github.com/NullHypothesis/bridgedb/commit/0beed8953e7a72a69b72045b2623d81b926012f1
 Here's the patch]. I used numpy to determine the quartiles. I originally
 hesitated to add yet another dependency – especially a bulky one like
 numpy – but we can remove it again once Python 3.8 (which has built-in
 support for quantiles) is available in Debian stable.

 Sounds like a great plan to include numpy for now and kick it out once
 Python 3.8 is available to you.

 Regarding the whiskers, I noticed that these are typically calculated
 differently than by your patch. Quoting the source of all truth:

 > The same data set can also be represented as a boxplot shown in Figure
 3. From above the upper quartile, a distance of 1.5 times the IQR is
 measured out and a whisker is drawn up to the '''largest observed point
 from the dataset''' that falls within this distance. Similarly, a distance
 of 1.5 times the IQR is measured out below the lower quartile and a
 whisker is drawn up to the '''lower observed point from the dataset'''
 that falls within this distance. All other observed points are plotted as
 outliers.[5] (https://en.wikipedia.org/wiki/Box_plot)

 In your test case you'd check for `lower-whisker` to be `1.0` and `upper-
 whisker` to be `3.0`.

 > On an unrelated note: Karsten, do we need to coordinate on when we
 deploy this patch? Note that the patch bumps the key `bridgedb-metrics-
 version` to 2 and adds several new fields for our internal metrics. Does
 this break anything on the metrics side of things?

 I think this should just work, but do you mind providing a sample version
 2 document for me to check?

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/31422#comment:19>
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