Amazon Forecast Diagnostics
When to use
Any Amazon Forecast investigation where the console alone is insufficient — dataset management, predictor training, forecast generation, accuracy evaluation, what-if analysis, or explainability.
Investigation workflow
Step 1 — Collect and triage
aws forecast list-dataset-groups
aws forecast list-predictors
aws forecast list-forecasts
aws forecast list-what-if-analyses
Step 2 — Domain deep dive
aws forecast describe-dataset-group --dataset-group-arn <arn>
aws forecast describe-auto-predictor --predictor-arn <arn>
aws forecast describe-forecast --forecast-arn <arn>
aws forecast get-accuracy-metrics --predictor-arn <arn>
Step 3 — Detailed investigation
aws cloudtrail lookup-events --lookup-attributes AttributeKey=EventSource,AttributeValue=forecast.amazonaws.com --max-results 20
aws forecast describe-dataset-import-job --dataset-import-job-arn <arn>
Read references/guardrails.md before concluding on any Forecast issue.
Tool quick reference
| Tool / API | When to use |
|---|---|
forecast list-dataset-groups |
List dataset groups |
forecast describe-auto-predictor |
Check predictor status |
forecast describe-forecast |
Check forecast status |
forecast get-accuracy-metrics |
Get predictor accuracy |
forecastquery query-forecast |
Query forecast values |
forecast list-what-if-analyses |
List what-if analyses |
forecast list-explainabilities |
List explainability jobs |
Gotchas: Amazon Forecast
- Dataset import requires specific CSV format with timestamp, target value, and item ID columns.
- AutoPredictor is recommended over legacy predictors. It automatically selects best algorithm.
- Predictor training can take hours. Training creates an immutable predictor.
- Forecast generation is separate from training. Must create forecast from predictor.
- Accuracy metrics (WAPE, RMSE, MASE) are available after training. Lower WAPE is better.
- What-if analysis requires an existing forecast. It models scenarios with modified data.
- Explainability shows feature importance. Requires predictor with explainability enabled.
- Forecast horizon must match predictor's forecast horizon setting.
Anti-hallucination rules
- Always cite specific ARNs, job IDs, or API responses as evidence.
- Training takes hours. Never assume immediate predictor availability.
- Forecast generation is separate from training. Never assume automatic forecast.
- AutoPredictor is recommended. Never default to legacy predictor APIs.
- Accuracy metrics are predictor-specific. Never assume universal accuracy.
- Spend no more than 2 minutes on any single hypothesis. Pivot if inconclusive.
14 runbooks
| Category | IDs | Covers |
|---|---|---|
| A — Datasets | A1-A2 | Dataset import, data format |
| B — Predictors | B1-B3 | Predictor training, AutoPredictor, accuracy |
| C — Forecasts | C1-C2 | Forecast generation, forecast query |
| D — What-If | D1-D2 | What-if analysis, what-if forecast |
| E — Explainability | E1 | Explainability analysis |
| F — Data Quality | F1-F2 | Time series quality, missing values |
| Z — Catch-All | Z1 | General troubleshooting |