Microsoft Fabric uses throttling to maintain optimal performance and reliability. Fabric limits the number of API calls within a time window per user, so a caller can only make a certain amount of calls to a specific public API, ensuring fair resource allocation and system stability and reliability.

Throttling policies take place for both the API caller and the API itself. This means, that Fabric limits the number of calls a specific caller can perform on a specific API.

Throttling message

When a user sends a number of requests that exceeds a predetermined limit during a time window, Fabric throttles further requests from that user for a short period.

When applications experience throttling, Fabric returns an HTTP status code 429 (Too many requests) with a Retry-After HTTP header in the response, indicating how many seconds the calling application has to wait before making a new request.

Below is a response example, suggesting that the user waits 55 seconds before retrying the call.

Screenshot that shows an HTTP response header.

Considerations and limitations

Every Fabric admin and core public API call is throttled.

Next steps