[metrics-bugs] #25774 [Metrics/Ideas]: Record latency measurements using OnionPerf

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#25774: Record latency measurements using OnionPerf
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 Reporter:  irl            |          Owner:  metrics-team
     Type:  project        |         Status:  needs_revision
 Priority:  Medium         |      Milestone:
Component:  Metrics/Ideas  |        Version:
 Severity:  Normal         |     Resolution:
 Keywords:                 |  Actual Points:
Parent ID:                 |         Points:
 Reviewer:  irl            |        Sponsor:
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Changes (by irl):

 * status:  needs_review => needs_revision
 * reviewer:   => irl


Comment:

 Replying to [comment:1 karsten]:
 > If we were to put this on Tor Metrics, we'd probably make the source
 configurable and display either all sources at once or just a single one
 of them. And we'd probably stack the three graphs for the hops vertically,
 rather than horizontally, or alternatively use three colors for the three
 hops.

 This sounds good. This is not how I was expecting the graphs to look, the
 2nd hop seems to happen faster than the 1st hop. Perhaps there are some
 overheads we incur on the 1st hop that regular clients wouldn't have
 because we don't use guards. (I don't think we can fix this, it's just
 something we should work out and document.)

 It looks like there is overlap in the ranges for the 2nd and 3rd hops, so
 I think having separate plots is necessary and putting the 3 on the same
 plot with different colours wouldn't be readable.

 The plots that share the same row are easier to compare than those that
 share the same column, so we should consider what users may want to
 compare.

 For parameters, the current parameters for the existing performance graphs
 are all applicable except that it probably does not make sense to have
 this for the onion measurements.

 > I think this already addesses the "circuit build latency" part in the
 ticket description. What exactly is meant by "end-to-end latency" there?
 Maybe there's data for that, too.

 End-to-end latency is the latency to send data across the circuit. From
 looking at the TorPerf spec, this would be the difference between
 DATAREQUEST and DATARESPONSE divided by 2.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/25774#comment:3>
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