What is the metric used to measure API request capacity?

The metric that accurately measures API request capacity is requests per second. This metric indicates how many API calls can be processed by a server in a one-second interval. It provides a clear understanding of the performance limits and capabilities of an API, allowing developers and system architects to assess whether the API can handle expected traffic loads effectively.

Requests per second is particularly relevant for evaluating the scalability and responsiveness of an API in real-time scenarios. If an API is performing at high requests per second, it suggests that the system is capable of handling multiple concurrent users and tasks without significant delays.

In contrast, other metrics such as total lookups per second are more specific to data retrieval processes and may not fully encapsulate the overall performance of an API, connections per second refers to the number of active connections rather than the number of requests handled, and IOPS (Input/Output Operations Per Second) is primarily used to measure the performance of storage devices and doesn’t directly relate to API request handling.