Scraping

Prometheus initiates HTTP requests toward two target endpoints. A valid response returns samples and yields up=1; a refused scrape ends at a red stop and yields up=0. These are collection outcomes.

Prometheus pulls metrics and records scrape outcomes

Prometheus collects metrics by requesting an HTTP endpoint on each configured target. The target exposes observations; the collector chooses when to scrape, parses the response, and stores samples. This arrangement makes collection failures observable from the collector’s perspective. It does not guarantee that the endpoint is reachable, that every expected target was discovered, or that the application’s user journeys work. ...