Failure Modes
PreFlight — Deterministic Upstream Data Ingestion Gate
Failure Classification
Failure is a deterministic enforcement outcome indicating that ingestion safety cannot be mechanically verified.
- A structural boundary verdict
- A consequence of provable ingestion risk
- Not a runtime error
PreFlight enforces structural safety only.
Structural Determinism Requirements
Ingestion safety requires:
- Deterministic structural traversal
- Stable column alignment
- Type-consistent field representation
- Unambiguous parsing conditions
Loss of structural determinism results in enforcement action.
1. Schema Structural Integrity
Failure occurs when column structure cannot be deterministically aligned across records.
- Column count mismatch
- Row-level structural inconsistency
- Structural drift across records
- Unstable delimiter interpretation
Structural integrity is a prerequisite for ingestion safety.
2. Row Iteration Viability
Failure occurs when dataset rows cannot be deterministically traversed.
- Corrupted record boundaries
- Malformed row termination
- Truncated structural segments
- Non-iterable record sequences
If rows cannot be traversed deterministically, ingestion safety cannot be verified.
3. Numeric Type Corruption
Failure occurs when declared numeric fields contain non-coercible or structurally invalid values.
- Mixed numeric and non-numeric tokens
- Irreversible coercion states
- Invalid numeric encoding
Declared numeric context must remain structurally stable.
4. Multiple Valid Representations
Exposure occurs when a field supports more than one structurally valid representation without corruption.
- Mixed timestamp formats
- Mixed numeric encodings
- Alternative structural representations within a single field
This condition may reduce to WARN when structural exposure exists without deterministic failure.
5. High Null Density
Exposure occurs when declared fields exhibit structurally significant null concentration.
- Predominantly null columns
- Null behavior outside declared tolerance
Null concentration may introduce ingestion exposure without corruption.
6. Malformed or Truncated Rows
Failure occurs when record continuity or dataset termination cannot be deterministically confirmed.
- Incomplete trailing records
- Partial structural fragments
- File boundary corruption
Structural continuity is required for ingestion safety.
7. Text Encoding Corruption
Failure occurs when character encoding prevents deterministic parsing.
- Non-decodable byte sequences
- Encoding ambiguity
- Structural corruption introduced by invalid byte states
Parsing determinism must remain intact.
Evaluability Boundary
Evaluation requires mechanically sufficient structural evidence.
If ingestion safety cannot be verified under deterministic execution rules, the system does not issue PASS.
This condition reduces to ANALYSIS_INCOMPLETE.
Verdict Reduction Model
Independent test outcomes reduce mechanically to one of four outcomes:
- PASS
- WARN
- BLOCK
- ANALYSIS_INCOMPLETE
- No weighting
- No heuristics
- No interpretive aggregation
- No probabilistic logic
Verdict reflects structural enforcement only.
Failure Semantics
- BLOCK indicates deterministic ingestion failure
- WARN indicates structural exposure without proven corruption
- ANALYSIS_INCOMPLETE indicates insufficient structural evidence
PreFlight issues enforcement verdicts only. Ingestion decisions remain external.
Scope Limits
Failure modes describe ingestion safety violations only.
Not evaluated:
- Meaning
- Business correctness
- Analytical validity
- Model behavior
- Quality scoring
Operational Posture
- Upstream
- Deterministic
- Mechanical
- Auditable
- Non-interactive