CAF ships a Prometheus scraper implementation that allows exposing metrics from the actor system. User can create an instance of the scraper with the factory function caf::net::prometheus::scraper (include caf/net/prometheus.hpp). The scraper is designed to work with an HTTP server.

A minimal example for starting an HTTP server (see HTTP experimental) at port 8081 that responds to GET requests on /metrics could look like this:

auto server = net::http::with(sys)
                .route("/metrics", net::prometheus::scraper(sys))


Usually, users can simply use the configuration options of the actor system to export metrics: Exporting Metrics to Prometheus. When setting these options, CAF uses this implementation to start the Prometheus server in the background.