Function main

examples/random/main.go:74–144

()

}

func main() {
	var (
		addr              = flag.String("listen-address", ":8080", "The address to listen on for HTTP requests.")
		uniformDomain     = flag.Float64("uniform.domain", 0.0002, "The domain for the uniform distribution.")
		normDomain        = flag.Float64("normal.domain", 0.0002, "The domain for the normal distribution.")
		normMean          = flag.Float64("normal.mean", 0.00001, "The mean for the normal distribution.")
		oscillationPeriod = flag.Duration("oscillation-period", 10*time.Minute, "The duration of the rate oscillation period.")
	)

	flag.Parse()

	// Create a non-global registry.
	reg := prometheus.NewRegistry()

	// Create new metrics and register them using the custom registry.
	m := NewMetrics(reg, *normMean, *normDomain)
	// Add Go module build info.
	reg.MustRegister(collectors.NewBuildInfoCollector())

	start := time.Now()

	oscillationFactor := func() float64 {
		return 2 + math.Sin(math.Sin(2*math.Pi*float64(time.Since(start))/float64(*oscillationPeriod)))
	}

	// Periodically record some sample latencies for the three services.
	go func() {
		for {
			v := rand.Float64() * *uniformDomain
			m.rpcDurations.WithLabelValues("uniform").Observe(v)
			time.Sleep(time.Duration(100*oscillationFactor()) * time.Millisecond)
		}
	}()

	go func() {
		for {
			v := (rand.NormFloat64() * *normDomain) + *normMean
			m.rpcDurations.WithLabelValues("normal").Observe(v)
			// Demonstrate exemplar support with a dummy ID. This
			// would be something like a trace ID in a real
			// application.  Note the necessary type assertion. We
			// already know that rpcDurationsHistogram implements
			// the ExemplarObserver interface and thus don't need to
			// check the outcome of the type assertion.
			m.rpcDurationsHistogram.(prometheus.ExemplarObserver).ObserveWithExemplar(
				v, prometheus.Labels{"dummyID": strconv.Itoa(rand.Intn(100000))},
			)
			time.Sleep(time.Duration(75*oscillationFactor()) * time.Millisecond)
		}
	}()

	go func() {
		for {
			v := rand.ExpFloat64() / 1e6
			m.rpcDurations.WithLabelValues("exponential").Observe(v)
			time.Sleep(time.Duration(50*oscillationFactor()) * time.Millisecond)
		}
	}()