What problem does it solve? When a Spark notebook, job, or pipeline fails in Microsoft Fabric, finding the root cause requires digging through scattered logs, session states, and monitoring APIs. This Skill automates that triage with a systematic, read-only diagnostic workflow. ## Core Features & Use Cases - Failure Triage: Classify failures (driver/executor OOM, shuffle fetch failures, executor loss, library errors) using the Spark Advisor API, driver/executor logs, and job instance history. - Performance Diagnostics: Detect data skew, disk spill, GC pressure, heavy shuffles, and low core efficiency using stage metrics and the Resource Usage API with defined severity thresholds. - Pipeline Run Diagnosis: Query queryActivityRuns to diagnose every Spark activity in a failed pipeline run, including ForEach iterations, retries, and nested pipelines, with cell-level traceback extraction. - Offline Deep-Dive: Copy event logs to OneLake via the JobInsight API and start a local Spark History Server when online monitoring data is truncated or expired. - Use Case: A user asks "Why did my notebook ETL_Daily fail in workspace Production?" The Skill resolves the workspace and notebook, finds the failed Livy session, queries Spark Advisor, confirms data skew in stage metrics, and returns a severity-ordered report with fixes and a Notebook Snapshot link. ## Quick Start Ask the assistant to diagnose why your Fabric notebook or Spark job failed, providing the workspace name and item name or a pipeline run ID.