fabric-notebook-perf-remediatelisted

# Microsoft Fabric Notebook Performance remediate Systematic toolkit for diagnosing, analyzing, and resolving performance bottlenecks in Microsoft Fabric notebooks powered by Apache Spark. ## When to Use This Skill - Fabric notebook cells are running slowly or timing out - Spark jobs are being throttled with HTTP 430 errors - Capacity Metrics app shows high CU consumption - Data skew is causing unbalanced task execution - Shuffle operations are consuming excessive resources - Delta Lake tables have degraded read/write performance - OOM (Out of Memory) errors during notebook execution - Spark Advisor shows warnings or errors in cell output - Session startup is slow or sessions expire unexpectedly - Pipeline-triggered notebooks are queued for extended periods ## Prerequisites - Workspace Admin or Contributor role in the target Fabric workspace - Access to the Fabric Monitoring Hub for your capacity - Fabric Capacity Metrics app installed (for capacity-level analysis) - Familiarity with PySpark or Spark SQL syntax ## remediate Decision Tree Identify your symptom and follow the corresponding workflow. | Symptom | Root Cause Category | Action | |---------|-------------------|--------| | Notebook cell runs for minutes on small data | Spark session config or query plan | See [Spark Session Tuning](./references/spark-session-tuning.md) | | HTTP 430 error on job submission | Capacity exhausted, concurrency limit | See [Capacity and Throttling](#capacity-and-throttling) | | One