code-root-cause-analysislisted

# Root Cause Analysis Systematic investigation of errors and failures using historical wiki knowledge and external documentation. ## When to Use This Skill **Use for:** - Debugging errors with stack traces or error messages - Investigating incidents or outages - Finding historical context for similar issues in personal-wiki - Analyzing recurring problems across time - Searching for past solutions or workarounds **Don't use for:** - Simple syntax errors (use direct debugging) - Issues without error context (use exploratory debugging) - Real-time incident response (use incident management workflows) ## Core Investigation Workflow ### Phase 1: Extract Error Signature Before searching, extract the searchable error signature: ``` Error Signature Components: 1. Error type/class: NullPointerException, ConnectionRefused, OOMKilled 2. Error message (first line, sanitized) 3. Key stack frame: Class.method or function name 4. Service/component name 5. Error code (if present): HTTP 503, Exit code 137, SQLSTATE 42P01 ``` **Quick Extraction Pattern:** ``` Given: "java.lang.NullPointerException: Cannot invoke method on null at com.example.UserService.getUser(UserService.java:42)" Extract: - Type: NullPointerException - Location: UserService.getUser - Searchable: "NullPointerException UserService" OR "getUser null" ``` ### Phase 2: Search Historical Context (Wiki) Search Logseq for historical occurrences and solutions: **Search Locations:** | Location | Pattern | Purpose | |----