transcription/docs/ver1/ver1-step2-results.md

Ver1 Step 2 Results: Error Handling & Reliability Hardening

Summary

Step 2 implementation is complete for the planned reliability and error-handling hardening scope:

1. Worker retries are now explicit, bounded, and category-driven.
2. Error behavior is more consistent across worker/API/UI boundaries.
3. Logging now includes stronger boundary context in key failure paths.
4. Test coverage was expanded for retry policy and new reliability settings.

Implemented Changes

1) Worker retry policy and terminal behavior

• Updated src/transcription/models.py:
  • Added Job.retry_count with default 0.
• Updated src/transcription/config.py:
  • Added worker_max_retries.
  • Added worker_retry_backoff_seconds.
• Updated src/transcription/worker.py:
  • Added bounded retry decision path (_should_retry).
  • Added requeue behavior (_requeue_for_retry) for retriable errors.
  • Added deterministic terminal failure behavior (_finalize_failed_job).
  • Preserved transcript failure detail persistence (error_id, category, suggestion).

2) API fallback normalization hardening

• Updated src/transcription/api/errors.py:
  • Fallback handler now emits safe generic internal message for unhandled exceptions.
  • Added structured boundary logging fields including operation and exception type.

3) UI interaction reliability guard

• Updated src/transcription/ui/upload_page.py:
  • Added duplicate in-flight submission guard to prevent repeated upload handling while busy.

4) Observability/logging improvements

• Updated worker logs in src/transcription/worker.py to include operation and domain identifiers in key transitions:
  • pick
  • retry
  • transcribed
  • failed

Test Coverage Added/Updated

• Updated tests/test_models.py:
  • Assert retry_count default.
• Updated tests/test_config.py:
  • Added worker retry settings default test.
• Updated tests/services/test_worker.py:
  • Added retriable requeue test.
  • Added retry-exhaustion terminal failure test.
  • Updated existing tests for settings-driven worker behavior.
• Existing API error tests remained green with fallback behavior updates:
  • tests/api/test_error_responses.py

Verification Evidence

Executed and passing:

• uv run pytest tests/services/test_worker.py tests/test_models.py tests/test_config.py tests/api/test_error_responses.py -q
• uv run pytest -q

Residual Risks / Follow-ups

1. Retry policy currently uses simple fixed backoff; richer strategy (exponential/jitter) can be added in later hardening.
2. Full cross-layer structured logging standardization can be expanded in Step 6 observability work.
3. A formal Step 2 error-path inventory artifact (ver1-step2-audit.md) is still recommended for governance completeness.

Step 2 Exit Assessment

• Error taxonomy and envelope stability: met
• Bounded retry and terminal failure behavior: met
• Worker reliability controls: met
• UI interaction hardening for duplicate actions: met
• Test coverage expansion and full-suite regression safety: met

Step 2 is complete and ready to hand off to Ver1 Step 3.