Microsoft Fabric Error:
HTTP 429
What does this error mean?
A script or application calling Fabric APIs (such as Lakehouse metadata APIs) received an HTTP 429 Too Many Requests response because it exceeded the allowed number of requests within a time window.
Common causes
- 1A script calling Lakehouse metadata APIs (ListTables, GetTable) in a loop without rate limiting or backoff
- 2Multiple concurrent processes accessing the same Lakehouse artifacts simultaneously
- 3Automated pipelines or notebooks making too many API calls in a short burst
- 4Missing retry logic with exponential backoff in application code consuming Fabric APIs
How to fix it
- 1Implement exponential backoff and retry logic in any code that calls Fabric APIs — wait longer between each retry attempt.
- 2Add a delay between API calls in scripts that enumerate or poll Fabric metadata (e.g., wait 1–5 seconds between ListTables calls).
- 3Reduce the number of concurrent processes accessing the same Fabric artifacts.
- 4Cache API responses where possible to avoid redundant calls (e.g., cache table metadata instead of re-fetching on each iteration).
- 5Respect the Retry-After header returned in the 429 response — wait the specified number of seconds.