logging-standards

# Logging Standards Skill ## Purpose Standards for consistent, useful logging across all application layers. ## Auto-Invoke Triggers - Adding log statements - Configuring logging infrastructure - Debugging issues - Setting up monitoring --- ## Log Levels | Level | Use Case | Example | |-------|----------|---------| | **TRACE** | Detailed debugging | Variable values, loop iterations | | **DEBUG** | Diagnostic info | Method entry/exit, state changes | | **INFO** | Normal operations | Request completed, job started | | **WARN** | Potential issues | Retry attempt, deprecated usage | | **ERROR** | Failures | Exception caught, operation failed | | **FATAL** | System failure | Cannot start, out of memory | ### Level Selection Rules - Production default: INFO - Development default: DEBUG - Never log TRACE in production - ERROR should always have context --- ## Log Message Format ### Structure ``` [timestamp] [level] [correlation-id] [logger] - message {structured-data} ``` ### Example ``` 2024-01-15T10:30:45.123Z INFO abc-123-def UserService - User created {"userId": 42, "email": "user@example.com"} ``` ### Message Guidelines - Start with action verb: "Creating user", "Processing order" - Be specific: "User 123 deleted" not "Deleted" - Include relevant IDs - Keep messages concise --- ## Structured Logging ### Required Fields | Field | Description | Example | |-------|-------------|---------| | timestamp | ISO 8601 format | 2024-01-15T10:30:45.123Z | | level | Log level ...