Prometheus Metrics

quic-go can expose metrics via Prometheus, providing a comprehensive overview of its operation. By leveraging the Tracer and ConnectionTracer structs, quic-go captures various events. These are the same structs used for qlog event logging.

Enabling Metrics Collection

In your application, expose a Grafana endpoint on http://localhost:5001/prometheus:

import "github.com/prometheus/client_golang/prometheus/promhttp"

go func() {
    http.Handle("/prometheus", promhttp.Handler())
    log.Fatal(http.ListenAndServe("localhost:5001", nil))
}()

Event that don’t belong to any QUIC connection, such as the sending of Version Negotiation packets, are captured on the Transport.Tracer:

quic.Transport{
	Tracer: metrics.NewTracer(),
}

Events belonging to a QUIC connection, such as the reason a connection was closed, are captured on the ConnectionTracer returned from Config.Tracer.

quic.Config{
	Tracer: metrics.DefaultConnectionTracer,
}

📝 Future Work

Define more metrics: #4554

Event Logging using qlog WASM