Add per-subject evaluation telemetry opt-out

[leoromanovsky]

Motivation

Applications need to evaluate flags while excluding selected subjects from evaluation telemetry. This adds the same explicit, per-subject control as the client SDKs. Applications keep ownership of their consent rules.

Changes and Decisions

• Add Provider.Options.enableEvaluationTelemetryOptOutParameter(boolean), disabled by default.
• Also support DD_FEATURE_FLAGS_EVALUATION_TELEMETRY_PER_SUBJECT_OPT_OUT_ENABLED=true. An explicit provider option overrides deployment configuration, including false.
• Honor only boolean true at dd_evaluation_telemetry_opt_out. Missing, false, null, and other types preserve telemetry.
• Suppress new evaluation EVP events/counts, OTel evaluation metrics, and automatic flag span enrichment.
• Preserve flag results, defaults, exposures, experimentation, application hooks, unrelated tracing, and queued data.
• Keep each decision within its evaluation. Concurrent and nested evaluations do not share subject state.

flowchart TD
    C[Per-evaluation subject context] --> P[Datadog provider]
    P --> E[Evaluate flag]
    E --> R[Return flag result]
    E --> X[Existing exposure handling: unchanged]
    E --> G{Evaluation telemetry opted out?}
    G -->|Yes| S[Skip new evaluation telemetry]
    G -->|No| T[Evaluation EVP, OTel metrics, flag span enrichment]

Loading

// Configure once.
OpenFeatureAPI api = OpenFeatureAPI.getInstance();
api.setProviderAndWait(new Provider(
    new Provider.Options().enableEvaluationTelemetryOptOutParameter(true)));
Client client = api.getClient();

// Supply each request's subject decision. Do not replace the global context.
boolean enabled = client.getBooleanValue("my-feature", false,
    new ImmutableContext(user.getId(), Collections.singletonMap(
        "dd_evaluation_telemetry_opt_out",
        new Value(user.hasDeclinedEvaluationTelemetry()))));

The parameter name is identical across languages. This control does not opt a subject out of experiments or exposure logging.

The module's existing coverage gate still fails on the unchanged base and this branch. This PR does not change its thresholds.

[dd-octo-sts]

🟢 Java Benchmark SLOs — All performance SLOs passed

Suite	Status
Startup	🟢 pass

SLO thresholds are defined here based on automatically generated metrics. A warning is raised when results are within 5% of the threshold.

PR vs. master results

Scenario	Candidate	master	Δ (95% CI of mean)
startup:insecure-bank:iast:Agent	13.94 s	13.98 s	[-1.1%; +0.5%] (no difference)
startup:insecure-bank:tracing:Agent	12.85 s	12.91 s	[-1.1%; +0.3%] (no difference)
startup:petclinic:appsec:Agent	17.20 s	17.08 s	[-0.3%; +1.7%] (no difference)
startup:petclinic:iast:Agent	17.04 s	17.04 s	[-1.0%; +0.9%] (no difference)
startup:petclinic:profiling:Agent	16.87 s	16.96 s	[-1.8%; +0.8%] (no difference)
startup:petclinic:sca:Agent	17.07 s	16.76 s	[+1.0%; +2.7%] (significantly worse)
startup:petclinic:tracing:Agent	16.18 s	16.09 s	[-0.4%; +1.5%] (no difference)

Commit: f6d47500 · CI Pipeline · Benchmarking Platform UI

---

Load and DaCapo benchmarks can be triggered manually in the GitLab pipeline. Results will appear in the Benchmarking Platform UI after completion.

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-10-15T12:15:13.953043Z	39ace88	Draft marked ready
🔒 Security Review	✅ Completed 2026-10-15T12:16:35.864516Z	39ace88	Draft marked ready

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[datadog-datadog-prod-us1-2]

More details

The opt-out gates evaluation telemetry independently of exposure logging and flag resolution. The completed static review identified no reportable defects.

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[datadog-datadog-prod-us1-2]

More details

The evaluation telemetry gate leaves exposure handling and flag results intact. The completed static review identified no actionable defects.

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