disable deprecated runtime metrics by default

[dprotaso]

Part of #5655

[dashpole]

I think we also need to update/reorganize the package documentation in

opentelemetry-go-contrib/instrumentation/runtime/doc.go

Line 4 in 80afd76

// Package runtime implements the conventional runtime metrics specified by OpenTelemetry.

to reflect that the new metrics are always produced, and that the env var re-enables the old ones. We should probably flip the docs and list the old ones first, and new ones second.

We should also make it so that we still enable the new metrics even when the legacy ones are re-enabled. I think we shouldn't return in this statement anymore:

opentelemetry-go-contrib/instrumentation/runtime/runtime.go

Line 47 in 80afd76

return deprecatedruntime.Start(meter, c.MinimumReadMemStatsInterval)

[dashpole]

This needs a changelog entry.

[dprotaso]

@dashpole where do those go?

[dprotaso]

ok @dashpole changes are done PTAL

[dprotaso]

So if this merges when is the next release that this would be a part of?

[dashpole]

The last release was 2 weeks ago, so probably in the next week. We do releases as needed, but generally every 2 weeks

[codecov]

Codecov Report

Attention: Patch coverage is 62.50000% with 3 lines in your changes missing coverage. Please review.

Project coverage is 82.3%. Comparing base (b0a27cc) to head (14e77d6).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
instrumentation/runtime/runtime.go	0.0%	3 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##            main   #7418     +/-   ##
=======================================
- Coverage   82.3%   82.3%   -0.1%     
=======================================
  Files        205     205             
  Lines      17967   17967             
=======================================
- Hits       14801   14791     -10     
- Misses      2731    2738      +7     
- Partials     435     438      +3     

Files with missing lines	Coverage Δ
instrumentation/runtime/internal/x/x.go	100.0% <100.0%> (ø)
instrumentation/runtime/runtime.go	68.7% <0.0%> (-0.7%)	⬇️

... and 2 files with indirect coverage changes

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• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[pellared]

lint fails: https://github.com/open-telemetry/opentelemetry-go-contrib/actions/runs/15400325903/job/43331177212?pr=7418

[dprotaso]

lint failure seems unrelated

Error: R] https://opentelemetry.io/docs/reference/specification/resource/semantic_conventions/cloud_provider/aws/ecs/ | Network error: error sending request for url (https://opentelemetry.io/docs/specs/semconv/resource/) Maybe a certificate error?

[dprotaso]

is codecov/patch check blocking?

[dashpole]

No

[dashpole]

@open-telemetry/go-approvers any concerns with enabling new go runtime metrics by default, and disabling the old ones?

[pellared]

Please update these docs: https://github.com/open-telemetry/opentelemetry-go-contrib/blob/main/instrumentation/runtime/internal/x/README.md#include-deprecated-metrics

Moreover, this line can be now removed:

opentelemetry-go-contrib/instrumentation/runtime/runtime_test.go

Line 66 in b0a27cc

t.Setenv("OTEL_GO_X_DEPRECATED_RUNTIME_METRICS", "false")

[dprotaso]

@pellared made the changes let me know if you need anything else

[pellared]

LGTM

@dashpole, can you double-check? I think we could create an issue to remove OTEL_GO_X_DEPRECATED_RUNTIME_METRICS in v1.38.0.

[pellared]

@dashpole, PTAL at my suggestions, feel free to edit them and apply 😉

[dprotaso]

Thanks everyone - when's the next release planned?

[dashpole]

Looks like one PR left in the contrib milestone: https://github.com/open-telemetry/opentelemetry-go-contrib/milestone/31, and a bit of work left in core: https://github.com/open-telemetry/opentelemetry-go/milestone/70