Fabric Spark Pool Optimiser
Fabric Spark Pool Optimiser — right-size your Spark pools in 3 minutes
Every workspace in Microsoft Fabric gets the same default Spark pool. Medium node, up to 10 nodes. Nobody changes it — even in production, even when the actual workload is a 5,000-row dimension table or a monitoring notebook reading 0.002 GB.
This notebook analyses 7 days of real Spark session history across all your workspaces and tells you exactly which pools are oversized, undersized, or correctly sized — with a step-by-step configuration guide for each one.
What it does:
- Auto-discovers all workspaces you have access to
- Detects orchestrator workspaces automatically (runMultiple / Data Factory)
- Separates automated pipeline sessions from interactive dev sessions — dev sessions skew duration data and are excluded from the CU calculation
- Analyses GB read/written/shuffled via the Spark History stages API
- Estimates monthly CU savings based on real usage
- Renders an interactive dashboard directly in the notebook output
No lakehouse needed. No configuration. Just import and Run All.
Tested across two organisations. In one run: 50 workspaces analysed, 8 pools to change, 1,441 CU estimated monthly saving.
Feedback welcome — especially if you find API behaviour that differs in your environment.