Add Central OpenTelemetry Benchmarks Repository project proposal

.cspell.yaml

@@ -30,6 +30,7 @@ words:
   - calendar-localization-ptbr
   - Causely
   - Cheler
+  - cijothomas
   - Ciukaj
   - Collibra
   - Coralogix

projects/central-benchmarks-repository.md

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+# Central OpenTelemetry Benchmarks Repository
+
+## Description
+
+This project establishes
+`open-telemetry/benchmarks` as
+the project-owned home for cross-language performance scenarios, with a public
+dashboard that tracks release-over-release results.
+
+The initial scope is intentionally narrow: stand up the repository, land one
+shared scenario (S1: counter API call), and publish a dashboard with data
+points from 2-3 language implementations. Working prototypes for .NET, Rust,
+and Java already exist at
+[`cijothomas/otel-benchmarks`](https://github.com/cijothomas/otel-benchmarks)
+with a live dashboard at
+<https://cijothomas.github.io/otel-benchmarks/>, so v1 is essentially a move
+and a permissions handshake.
+
+## Background
+
+The technical proposal is captured in
+[OTEP 5109](https://github.com/open-telemetry/opentelemetry-specification/pull/5118).
+Today many language SIGs run their own benchmarks, in their own repos, on
+their own schedules, with no cross-language view. A central repository
+gives the project a single, citable answer to "how does OTel perform across
+languages, and how is that changing over time?" without each SIG having to
+give up its own internal CI benchmarking.
+
+## Why It Matters
+
+OpenTelemetry's
+[mission](https://github.com/open-telemetry/community/blob/main/mission-vision-values.md)
+is to make high-quality telemetry a built-in feature of cloud-native software.
+Performance directly determines whether that adoption actually happens —
+library authors will not instrument with OTel natively if doing so adds
+meaningful overhead, and operators will not enable signals that cost too
+much. A central, public benchmarks repository is how the project shows the
+world that we walk the talk on performance: results are visible, comparable
+across languages, and tracked release-over-release.
+
+Concretely:
+
+- **Cross-language visibility**: today there is no single place to see, for
+  the same scenario, how each language implementation performs.
+- **Release-over-release trend**: per-release data points show whether the
+  project is getting faster or slower over time, per language.
+- **Library author confidence**: scenarios like S1 (cost of a counter API
+  call when no SDK is wired up) let library authors evaluate the cost of
+  instrumenting their libraries natively with OTel.
+
+## Deliverables
+
+This is a short project with a definitive ending. v1 is done when:
+
+1. `open-telemetry/benchmarks` exists, with the layout from
+   [OTEP 5109](https://github.com/open-telemetry/opentelemetry-specification/pull/5118)
+   and `CODEOWNERS` set up.
+2. Scenario S1 is implemented and published for at least 2 languages.
+3. The dashboard is public and reachable from the repo README.
+
+Everything beyond this (more scenarios, more languages, demo-based e2e
+scenarios) is deliberately out of scope for v1 and tracked as future work in
+the OTEP.
+
+## Staffing
+
+This is a small project; staffing is intentionally minimal.
+
+### TC Sponsor
+
+- David Ashpole ([@dashpole](https://github.com/dashpole))
+
+### GC Sponsor
+
+- Trask Stalnaker ([@trask](https://github.com/trask))
+
+### Repository maintainers
+
+- Cijo Thomas ([@cijothomas](https://github.com/cijothomas))
+- Martin Costello ([@martincostello](https://github.com/martincostello))
+
+The maintainers will provide guidance to language SIGs on contributing a
+harness for their implementation, and to anyone proposing a new scenario
+(scope, methodology, expected outputs). Ownership follows the same model
+as [`opentelemetry.io`](https://github.com/open-telemetry/opentelemetry.io):
+the repository has its own maintainers (above) for shared content
+(scenarios, workflows, top-level docs), while each per-language harness
+folder is owned via `CODEOWNERS` by the approvers of the corresponding
+language SIG. This means onboarding a new language does not require any
+additional project-level staffing.
+
+## Timeline
+
+Once OTEP 5109 is accepted, the repository can be created and v1 wrapped
+up in 1-2 weeks of elapsed effort. The prototypes already work end-to-end;
+this project is mostly the move and the `CODEOWNERS` setup.
+
+## Future Possibilities
+
+Out of scope for v1, but plausible follow-ups (also captured in the OTEP):
+
+- Additional scenarios (span/log emission, sampled-out fast path, exporter
+  cost, enrichment cost, etc.).
+- Onboarding additional languages.
+- End-to-end scenarios run against the OpenTelemetry Demo (e.g. measuring
+  the cost of moving span filtering between SDK and Collector).
+
+If any of those grow large enough to need their own staffing or governance,
+they can be proposed as separate projects at that time.