[AchoArnold]

Summary

• Use the existing logger to mark warning/error spans with httpsms.must_sample=true; do not copy log messages into spans.
• Logger.WithSpan now receives the actual span rather than only its IDs. This removes the separate logger wrapper and all caller-offset machinery.
• Filter completed spans before the existing batch exporter: retain errors, recorded exceptions, explicit flags, database spans over 200ms, and truncated telemetry; export 50% of the rest using a trace-ID decision.
• Standalone logs and metric measurements are not sampled. Metric exemplars use only the stable sampled trace-ID subset so they do not point to spans discarded by this policy. Log messages, correlation fields, decorations, callers, and destinations are preserved.

Minimal scope

• Keep the original GORM logger and dedicated-database logging setup; only update existing span bindings.
• No second GORM logger, configuration layer, parameter filters, stack-walking, or log-severity text parsing.
• The extra test-double edits only update the WithSpan signature; no service, handler, listener, or validator behavior changes.
• Keep the two heartbeat database context-propagation fixes so database spans remain connected to their requests.
• Keep focused tests for sampling decisions, retention flags, slow database boundaries, truncation, and unchanged structured log output.

Tradeoffs

• All spans are still recorded locally; this reduces exported volume, not instrumentation overhead.
• Retained spans outside the normal 50% sample can have missing normal parent or sibling spans.
• Slow-database retention uses the span's measured duration and database attributes, independently of GORM's log timing/configuration.
• The shared processor is used by the Axiom and Google trace providers.

Validation

• go test ./pkg/telemetry ./pkg/services ./pkg/repositories ./pkg/handlers ./pkg/listeners ./pkg/validators ./pkg/middlewares ./pkg/di
• go build ./...
• No new lint issues across the same packages using golangci-lint run --new-from-rev=origin/main with Go 1.26.0.

[AchoArnold]

@greptileai review

[codacy-production]

Up to standards ✅

🟢 Issues 0 issues

Results:
0 new issues

View in Codacy

🟢 Metrics 107 complexity · 0 duplication

Metric	Results
Complexity	107
Duplication	0

View in Codacy

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[greptile-apps]

Confidence Score: 5/5

[High impact] The PR appears safe to merge; no new blocking issues were found.

Summary

The PR retains warning/error spans and applies a trace-ID-based 50% sample to remaining spans.

• Trace exporters send flagged spans and half of the rest.
• Warnings and errors now leave clues on their active spans.
• GORM query errors and slow queries now link to active spans.

No new actionable issues were found. No previous review threads were supplied. Tests were inspected but not run.

Diagram

%%{init: {'theme': 'neutral'}}%%
flowchart TD
  A[Span ends] --> B{Trace ID in 50% sample?}
  B -->|Yes| E[Queue for export]
  B -->|No| C{Error, exception, warning, or dropped telemetry?}
  C -->|Yes| E
  C -->|No| D[Do not export]

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_{Reviews (2) · Last reviewed commit: "fix(api): address trace sampling review ..." · Reviewed by Greptile}

[Copilot]

🟡 Changes recommended

Raw error text can expose customer content and API keys in traces, while span retention, production database warning capture, and log caller attribution remain unreliable.

4 open issues

• Prevent sensitive error text and API keys from entering trace events · New
• Install the span-aware logger for production DedicatedDB warnings · New
• Preserve span retention signals after event and attribute eviction · New
• Adjust caller frame skipping for forwarded span-linked warnings · New

What changed in this PR

This PR reduces exported API trace volume by retaining warning/error spans and deterministically sampling 50% of remaining spans after completion. All spans remain locally recorded.

Changes:

• Adds a shared sampling processor for Axiom and Google trace providers.
• Links application and GORM warning/error logs to active spans.
• Adds tests for sampling, error retention, logger decoration, and event limits.

File	Description
api/​pkg/​telemetry/​span_logger.go	Adds span-linked warning, error, and fatal logging.
api/​pkg/​telemetry/​sampling_span_processor.go	Filters completed spans using severity and trace-ID sampling.
api/​pkg/​telemetry/​sampling_span_processor_test.go	Tests sampling decisions and retention signals.
api/​pkg/​telemetry/​otel_tracer.go	Wraps context loggers with span-aware logging.
api/​pkg/​telemetry/​gorm_logger.go	Routes GORM logs through span-aware loggers.
api/​pkg/​di/​container.go	Installs the shared processor for both trace providers.

_{Review effort: Balanced}

[AchoArnold]

@greptileai review

[Copilot]

🟡 Changes recommended

Unredacted log messages can expose credentials and message bodies in trace exports, while warning spans may still be dropped when event attributes are truncated.

4 open issues

• Prevent sensitive error text and API keys from entering trace events
• Pass the active context to heartbeat database updates · New
• Preserve the dedicated database logger destination · New
• Avoid formatting successful queries when warnings are not emitted · New

1 previously missed issue

In code that hasn't changed since last review

Limit request bodies copied into trace events

api/​pkg/​telemetry/​span_logger.go:48

[P2] This copies unrestricted error text into queued spans; HTTPRequestLogger and MessageHandler.PostSend include entire request bodies in their warnings. Large rejected requests therefore increase trace-buffer memory use and export payload size in addition to the existing log traffic. Omit the message from the span event, keeping the severity marker for retention and the full text in the standalone log.

3 resolved since last review

• Adjust caller frame skipping for forwarded span-linked warnings
• Preserve span retention signals after event and attribute eviction
• Install the span-aware logger for production DedicatedDB warnings

_{Review effort: Balanced}

[Copilot]

🟡 Changes recommended

SQL parameters can leak despite redaction, uppercase warning and error events can be dropped, and delegated GORM logs lose the original query call site.

3 open issues

• Honor GORM parameter filtering in custom loggers · New
• Preserve original query call sites in delegated GORM logs · New
• Retain span events with uppercase ERROR and WARN severity · New

4 resolved since last review

• Prevent sensitive error text and API keys from entering trace events
• Avoid formatting successful queries when warnings are not emitted
• Preserve the dedicated database logger destination
• Pass the active context to heartbeat database updates

_{Review effort: Balanced}

[Copilot]

🔵 Needs a closer look

Fatal logging’s interaction with span completion and telemetry flushing warrants human assessment.

No open issues 🎉

3 resolved since last review

• Honor GORM parameter filtering in custom loggers
• Retain span events with uppercase ERROR and WARN severity
• Preserve original query call sites in delegated GORM logs

_{Review effort: Balanced}

[Copilot]

🟡 Changes recommended

The processor can discard spans with truncated link data and leave metric exemplars pointing to discarded spans.

2 open issues

• Prevent exemplars from referencing discarded spans · New
• Include dropped link telemetry in span truncation retention checks · New

_{Review effort: Balanced}