Add support for tracing::Span::recorded fields in metrics-tracing-context

[zohnannor]

I wondered for the reason of why recorded fields are not added to the Labels and found none. Implemented it as just Label::extend_from_labels call in a Layer::on_record method. For the tests I am not sure, maybe I missed some corner case, but I can't see such a case.

P.S. Should I ignore falling CI checks?

[tobz]

I still need to read over the documentation changes, but left at least one bit of feedback on a required change.

[tobz]

Overall, this is looking good and just needs a little more polish. I still haven't looked fully at the unit tests or benchmarks, since I just wanted to make sure any relevant code changes are in place before thinking about that stuff.

[tobz]

One more small functional change we need to make, then I'll do the final review over the tests.

Appreciate your patience so far on this as my time has been a bit limited lately. 😓

[tobz]

Looking good, but it still seems like we don't quite have the label priority logic correct.

[tobz]

Alright, this is very close, but it looks like we changed one bit of filtering logic during some of the refactoring that just needs to be changed back.

Once that's fixed (and the other bit I made a note about in Cargo.toml) this should be ready to merge. 🎉

[zohnannor]

Pretty sad perf stats. Ready for a review though.

     Running benches/layer.rs (/home/zohnannor/dev/metrics/target/release/deps/layer-5bf703a34fc6c1b2)
Gnuplot not found, using plotters backend
layer/base case         time:   [923.19 ps 923.33 ps 923.48 ps]
                        change: [-16.774% -16.758% -16.741%] (p = 0.00 < 0.05)
                        Performance has improved.
Found 8 outliers among 100 measurements (8.00%)
  4 (4.00%) high mild
  4 (4.00%) high severe
layer/no integration    time:   [928.33 ps 928.41 ps 928.52 ps]
                        change: [-14.183% -14.125% -14.074%] (p = 0.00 < 0.05)
                        Performance has improved.
Found 3 outliers among 100 measurements (3.00%)
  1 (1.00%) high mild
  2 (2.00%) high severe
layer/tracing layer only
                        time:   [923.75 ps 923.78 ps 923.81 ps]
                        change: [-14.670% -14.622% -14.579%] (p = 0.00 < 0.05)
                        Performance has improved.
Found 8 outliers among 100 measurements (8.00%)
  6 (6.00%) high mild
  2 (2.00%) high severe
layer/metrics layer only
                        time:   [25.805 ns 26.988 ns 28.176 ns]
                        change: [+17.291% +21.416% +25.369%] (p = 0.00 < 0.05)
                        Performance has regressed.
layer/full integration  time:   [270.72 ns 270.85 ns 270.98 ns]
                        change: [+50.150% +50.248% +50.344%] (p = 0.00 < 0.05)
                        Performance has regressed.

     Running benches/visit.rs (/home/zohnannor/dev/metrics/target/release/deps/visit-1cf93c53aa04b250)
Gnuplot not found, using plotters backend
visit/record_str        time:   [23.671 ns 23.686 ns 23.699 ns]
                        change: [+137.50% +138.60% +139.73%] (p = 0.00 < 0.05)
                        Performance has regressed.
visit/record_bool[true] time:   [18.172 ns 18.179 ns 18.186 ns]
                        change: [+201.05% +201.53% +201.80%] (p = 0.00 < 0.05)
                        Performance has regressed.
Found 6 outliers among 100 measurements (6.00%)
  1 (1.00%) low severe
  1 (1.00%) low mild
  4 (4.00%) high mild
visit/record_bool[false]
                        time:   [18.097 ns 18.099 ns 18.101 ns]
                        change: [+199.13% +199.29% +199.44%] (p = 0.00 < 0.05)
                        Performance has regressed.
Found 11 outliers among 100 measurements (11.00%)
  3 (3.00%) high mild
  8 (8.00%) high severe
visit/record_i64        time:   [25.666 ns 25.673 ns 25.681 ns]
                        change: [+92.582% +92.723% +92.862%] (p = 0.00 < 0.05)
                        Performance has regressed.
Found 6 outliers among 100 measurements (6.00%)
  1 (1.00%) low severe
  2 (2.00%) low mild
  1 (1.00%) high mild
  2 (2.00%) high severe
visit/record_u64        time:   [25.482 ns 25.488 ns 25.495 ns]
                        change: [+94.980% +95.075% +95.167%] (p = 0.00 < 0.05)
                        Performance has regressed.
Found 2 outliers among 100 measurements (2.00%)
  1 (1.00%) high mild
  1 (1.00%) high severe
visit/record_debug      time:   [163.06 ns 163.16 ns 163.26 ns]
                        change: [+21.900% +22.026% +22.130%] (p = 0.00 < 0.05)
                        Performance has regressed.
Found 5 outliers among 100 measurements (5.00%)
  1 (1.00%) low severe
  1 (1.00%) low mild
  3 (3.00%) high mild
visit/record_debug[bool]
                        time:   [39.089 ns 39.096 ns 39.104 ns]
                        change: [+73.869% +74.077% +74.278%] (p = 0.00 < 0.05)
                        Performance has regressed.
Found 6 outliers among 100 measurements (6.00%)
  1 (1.00%) low severe
  3 (3.00%) low mild
  1 (1.00%) high mild
  1 (1.00%) high severe
visit/record_debug[i64] time:   [46.002 ns 46.010 ns 46.018 ns]
                        change: [+67.113% +67.556% +67.989%] (p = 0.00 < 0.05)
                        Performance has regressed.
Found 5 outliers among 100 measurements (5.00%)
  2 (2.00%) high mild
  3 (3.00%) high severe
visit/record_debug[u64] time:   [43.717 ns 43.731 ns 43.746 ns]
                        change: [+62.503% +62.569% +62.631%] (p = 0.00 < 0.05)
                        Performance has regressed.
Found 2 outliers among 100 measurements (2.00%)
  2 (2.00%) high mild

As an image

[tobz]

Woohoo, this is ready to merge. 🎉

The performance numbers are kind of "eh, whatever": a big increase, but it's still so fast overall that it shouldn't be a problem for users of this crate.

[zohnannor]

Cool! Thank you for review! When should we expect the release? 🙂

[tobz]

I would say within the next two weeks.

There's a lot of changes queued up on master, with some that I still need to work on and get merged, plus some testing, documentation/changelog/release notes updates.

[zohnannor]

@tobz friendly ping~

[tobz]

👋🏻

Sorry, life has been very busy 😭 ... although I'm finally on holiday vacation starting today. 😀 Going to try and see if I can get release notes written up today and then cut releases for everything.

[tobz]

Released as metrics-tracing-context@v0.15.0.

Thanks again for your contribution. ❤️