# Rate limiting
Cognite Data Fusion (CDF) returns an HTTP
429 Too many requests response status code if a user sends too many requests in a given amount of time or issues conflicting requests concurrently ("rate limiting").
The capacity of all APIs scales up when the usage exceeds predefined limits over time, but there is a delay between the traffic increase and the capacity scale-up. In some situations, the total load from all users can exceed the full maximum capacity for the CDF project. Traffic from a single user or a specific project can never claim all capacity in a cluster.
Cognite recommends using a retry strategy based on truncated exponential backoff (opens new window) to handle sessions with HTTP response codes 429 (or 503). The strategy lets clients slow down the request frequency to maximize throughput without having to re-submit failing requests.
Learn more about exponential backoff: