What model does Prometheus use to record metrics?

Prometheus utilizes the HTTP pull model to record metrics, which means it actively scrapes metrics from configured endpoints at specified intervals. This model is distinct from a push model where the clients (or monitored systems) would send their metrics to the monitoring server. In the HTTP pull model, Prometheus makes requests to the endpoints, collecting data as it becomes available rather than relying on the endpoints to send it.

This approach allows for greater flexibility and ensures that Prometheus collects only the latest metrics directly from the sources. It also simplifies the management of monitoring because Prometheus can control when and how often it gathers data, accommodating performance and scalability needs effectively.

The other choices don't align with how Prometheus operates. The webhook model refers to a method of receiving data through a callback URL, which is not how Prometheus records metrics. The RESTful API model suggests a different mechanism where data is pushed or fetched through REST calls, but again, Prometheus's focus is on pulling data. Finally, the GraphQL model is specific to querying and manipulating data with more complex queries and wouldn't pertain to the metric collection methodology used by Prometheus.