Logging Error Handling

logging-error-handling

Registry Trigger

Use when

• design structured errors logging context propagation and safe diagnostics

Do not use when

• no task-local logging error handling decision is required

Skill Role

Define error meaning and propagation, diagnostic purpose, structured context, correlation, redaction, outcome classification, volume bounds, and evidence that failures remain actionable. This Skill may identify a security-relevant outcome and consume an accepted audit contract, but excludes ownership of protected audit-record semantics, integrity, retention, access, durability, and alert policy.

High-Value Rules

• Define error ownership and external meaning. Preserve causal context across layers while translating only at owned boundaries; distinguish user, domain, dependency, transient, permanent, cancellation, and unexpected outcomes relevant to caller action.
• Log an owned diagnostic event, not arbitrary data. Name audience, decision enabled, event point, stable identity, outcome, and retention need before selecting fields or severity.
• Preserve correlation across attempts and effects. Carry request, operation, trace, job, message, tenant-safe, and real or effective actor identity needed to reconstruct a causal path without confusing retries with distinct business operations.
• Classify terminal outcome accurately. Avoid reporting handled intermediate retries, expected denial, cancellation, or fallback as terminal errors, and avoid hiding exhausted or partially applied work behind informational success.
• Minimize sensitive and unbounded content. Exclude secrets and raw bodies by default, transform personal or regulated fields according to current policy, and bound message, stack, collection, key, and payload expansion.
• Control volume and cardinality at the source. Derive event rate, level, sampling, aggregation, dynamic labels, and hot-path detail from current diagnostic need, cost, and incident consequence.
• Separate diagnostics from audit records. Identify the security-relevant outcome, accepted audit dependency, unresolved semantics, integrity, retention, access, sink, or durability, named specialist handoff, and gap without claiming protected-record closure.
• Prove failure reconstruction and redaction. Exercise representative normal, denied, retry, timeout, cancellation, partial, and unexpected paths, then verify correlation, terminal classification, sensitive-field handling, and proof limits.

Anti-Patterns

• Log the same exception at each layer, producing duplicate noise without additional ownership or action.
• Store raw requests, tokens, personal data, stack detail, or dynamic high-cardinality values because they might help later.
• Treat a fallback or retry as success while the original failure, final disposition, or lost effect cannot be reconstructed.

Stop Conditions

Escalate when error ownership is ambiguous, correlation cannot join consequential effects, sensitive-field policy is unclear, or logging can expose secrets or tenant data. Also escalate when hot-path volume is unbounded, or current evidence cannot reconstruct the terminal outcome.

Output Contract

• logging and error decision with ownership, external meaning, diagnostic events, correlation, outcome classification, redaction, volume bounds, reconstruction evidence, unverified paths or sinks, proof limits, and residual risk
• accepted audit-contract dependency or named logging-design-gate/security-privacy-gate handoff for each security-relevant outcome; do not claim protected audit-record closure from diagnostic-log evidence

Targeted References