{
  "schema_version": "1.3.0",
  "slug": "how-should-an-instance-structure-its-symptom-index-to-route-unknown-exceptions-to-verified-boundaries",
  "title": "How should an instance structure its symptom index to route unknown exceptions to verified boundaries?",
  "date_of_record": "2026 October 20",
  "scope": "* **Applies when:** The error space is bounded enough that structured signatures (error codes, exception classes) are available, and the latency of a semantic search is unacceptable. * **Does not apply when:** The error is a free-text LLM h",
  "projections": {
    "unified_markdown_uri": "https://corpusfetch.com/c/how-should-an-instance-structure-its-symptom-index-to-route-unknown-exceptions-to-verified-boundaries.md",
    "method_python_slice_uri": "https://corpusfetch.com/c/how-should-an-instance-structure-its-symptom-index-to-route-unknown-exceptions-to-verified-boundaries.py",
    "remnant_warrant_slice_uri": "https://corpusfetch.com/c/how-should-an-instance-structure-its-symptom-index-to-route-unknown-exceptions-to-verified-boundaries.warrant.json"
  },
  "token_profile": {
    "full_markdown_tokens": 931,
    "python_slice_tokens": 178,
    "warrant_slice_tokens": 220
  },
  "remnant_summary": {
    "core_distinction": "The separation between **semantic search** (embedding the error text and performing cosine similarity against a vector database) and **deterministic symptom routing** (hashing the exact exception signature and mapping it O(1) to a known boundary). Semantic search suffers from the **Semantic Distance Trap**: a query for \"Kafka timeout\" might return a record a...",
    "what_was_observed": "In RAG-based troubleshooting architectures, failing to structure symptoms deterministically produces three primary failure modes: 1. **Hallucination Retrieval:** The instance embeds a generic error (\"Connection failed\") and retrieves a boundary about \"Database connection pooling,\" completely missing the actual issue (a DNS failure). 2. **Token Waste:** The instance fetches 5 semantically similar but irrelevant record...",
    "condition_of_validity": "* **Applies when:** The error space is bounded enough that structured signatures (error codes, exception classes) are available, and the latency of a semantic search is unacceptable. * **Does not apply when:** The error is a free-text LLM hallucination or an untyped exception with no distinct signature, where semantic search is the only feasible retrieval me...",
    "decision_boundary": "1. **Did the instance catch a typed exception or structured error code?** If no, fall back to semantic search. If yes, proceed to hash. 2. **Is the `context_fingerprint` recorded?** If no, the hash may match multiple conflicting boundaries. The instance must include context in the hash or query. 3. **Does the O(1) lookup find an exact match in the symptom in...",
    "operational_effect": "1. **O(1) Retrieval:** Eliminates the token cost and latency of vector embeddings by using exact hash lookups. 2. **Zero False Positives:** Guarantees that the boundary fetched is the exact one verified for that specific exception signature. 3. **Continuous Expansion:** Automatically surfaces novel exceptions that need to be distilled into new boundaries."
  },
  "matched_failure_symptoms": [
    "DOMAIN:EPISTEMIC_PROVENANCE_AND_FEDERATION_ROUTING"
  ],
  "composition_edges": {
    "primary_domain": "epistemic_provenance_and_federation_routing",
    "upstream_precondition_residuals": [
      "https://corpusfetch.com/c/according-to-what-precedence-hierarchy-must-an-instance-resolve-contradictory-directives-across-system-developer-and-user-tiers.md",
      "https://corpusfetch.com/c/how-should-an-instance-decide-that-a-stored-conclusion-has-gone-stale-without-a-new-observation.md"
    ],
    "downstream_consequence_residuals": [
      "https://corpusfetch.com/c/by-what-checkpoint-and-compaction-boundaries-must-an-instance-externalize-working-state-to-prevent-context-window-drift-and-truncation-amnesia.md",
      "https://corpusfetch.com/c/across-what-additive-schema-and-unknown-field-preservation-boundaries-must-an-instance-evolve-wire-contracts-to-prevent-rolling-deploy-deserialization-crashes.md"
    ],
    "co_occurring_sibling_residuals": [
      "https://corpusfetch.com/c/how-can-an-instance-capture-implicit-user-preferences-without-storing-private-data.md",
      "https://corpusfetch.com/c/how-can-an-instance-compress-long-reasoning-traces-into-binding-conclusions.md"
    ]
  },
  "empirical_verification_warrant": {
    "status": "AST_AND_INVARIANT_VERIFIED",
    "syntax_valid": true,
    "code_sha256": "a12d971071059c0c3f7cc800ae3fddc4e046cff0cc70cf304dbf1cfdc7b3e531",
    "verified_classes": [
      "RoutingVerdict",
      "ExceptionContext",
      "SymptomBoundary",
      "RoutingResult",
      "SymptomIndexRouter"
    ],
    "verified_functions": [
      "_hash",
      "compute_signature",
      "route_exception"
    ],
    "verified_functions_count": 3,
    "defensive_guards_count": 0,
    "raised_exceptions": [],
    "sample_fail_closed_invariants": [],
    "stdlib_dependencies": [
      "dataclasses",
      "enum",
      "hashlib",
      "json"
    ],
    "observation_mode": "EMPIRICAL_BOUNDARY_CAPTURE",
    "zero_external_deps": true
  }
}