Update random example to use custom registry

Signed-off-by: Jéssica Lins <jessicaalins@gmail.com>
This commit is contained in:
Jéssica Lins 2022-10-21 16:47:21 +02:00
parent 0b7f4888b0
commit 6056615b26
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1 changed files with 45 additions and 31 deletions

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@ -30,6 +30,39 @@ import (
"github.com/prometheus/client_golang/prometheus/promhttp" "github.com/prometheus/client_golang/prometheus/promhttp"
) )
type metrics struct {
rpcDurations *prometheus.SummaryVec
rpcDurationsHistogram prometheus.Histogram
}
func NewMetrics(reg prometheus.Registerer, normMean, normDomain float64) *metrics {
m := &metrics{
// Create a summary to track fictional inter service RPC latencies for three
// distinct services with different latency distributions. These services are
// differentiated via a "service" label.
rpcDurations: prometheus.NewSummaryVec(
prometheus.SummaryOpts{
Name: "rpc_durations_seconds",
Help: "RPC latency distributions.",
Objectives: map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
},
[]string{"service"},
),
// The same as above, but now as a histogram, and only for the normal
// distribution. The buckets are targeted to the parameters of the
// normal distribution, with 20 buckets centered on the mean, each
// half-sigma wide.
rpcDurationsHistogram: prometheus.NewHistogram(prometheus.HistogramOpts{
Name: "rpc_durations_histogram_seconds",
Help: "RPC latency distributions.",
Buckets: prometheus.LinearBuckets(normMean-5*normDomain, .5*normDomain, 20),
}),
}
reg.MustRegister(m.rpcDurations)
reg.MustRegister(m.rpcDurationsHistogram)
return m
}
func main() { func main() {
var ( var (
addr = flag.String("listen-address", ":8080", "The address to listen on for HTTP requests.") addr = flag.String("listen-address", ":8080", "The address to listen on for HTTP requests.")
@ -41,34 +74,13 @@ func main() {
flag.Parse() flag.Parse()
var ( // Create a non-global registry.
// Create a summary to track fictional interservice RPC latencies for three reg := prometheus.NewRegistry()
// distinct services with different latency distributions. These services are
// differentiated via a "service" label.
rpcDurations = prometheus.NewSummaryVec(
prometheus.SummaryOpts{
Name: "rpc_durations_seconds",
Help: "RPC latency distributions.",
Objectives: map[float64]float64{0.5: 0.05, 0.9: 0.01, 0.99: 0.001},
},
[]string{"service"},
)
// The same as above, but now as a histogram, and only for the normal
// distribution. The buckets are targeted to the parameters of the
// normal distribution, with 20 buckets centered on the mean, each
// half-sigma wide.
rpcDurationsHistogram = prometheus.NewHistogram(prometheus.HistogramOpts{
Name: "rpc_durations_histogram_seconds",
Help: "RPC latency distributions.",
Buckets: prometheus.LinearBuckets(*normMean-5**normDomain, .5**normDomain, 20),
})
)
// Register the summary and the histogram with Prometheus's default registry. // Create new metrics and register them using the custom registry.
prometheus.MustRegister(rpcDurations) m := NewMetrics(reg, *normMean, *normDomain)
prometheus.MustRegister(rpcDurationsHistogram)
// Add Go module build info. // Add Go module build info.
prometheus.MustRegister(collectors.NewBuildInfoCollector()) reg.MustRegister(collectors.NewBuildInfoCollector())
start := time.Now() start := time.Now()
@ -80,7 +92,7 @@ func main() {
go func() { go func() {
for { for {
v := rand.Float64() * *uniformDomain v := rand.Float64() * *uniformDomain
rpcDurations.WithLabelValues("uniform").Observe(v) m.rpcDurations.WithLabelValues("uniform").Observe(v)
time.Sleep(time.Duration(100*oscillationFactor()) * time.Millisecond) time.Sleep(time.Duration(100*oscillationFactor()) * time.Millisecond)
} }
}() }()
@ -88,14 +100,14 @@ func main() {
go func() { go func() {
for { for {
v := (rand.NormFloat64() * *normDomain) + *normMean v := (rand.NormFloat64() * *normDomain) + *normMean
rpcDurations.WithLabelValues("normal").Observe(v) m.rpcDurations.WithLabelValues("normal").Observe(v)
// Demonstrate exemplar support with a dummy ID. This // Demonstrate exemplar support with a dummy ID. This
// would be something like a trace ID in a real // would be something like a trace ID in a real
// application. Note the necessary type assertion. We // application. Note the necessary type assertion. We
// already know that rpcDurationsHistogram implements // already know that rpcDurationsHistogram implements
// the ExemplarObserver interface and thus don't need to // the ExemplarObserver interface and thus don't need to
// check the outcome of the type assertion. // check the outcome of the type assertion.
rpcDurationsHistogram.(prometheus.ExemplarObserver).ObserveWithExemplar( m.rpcDurationsHistogram.(prometheus.ExemplarObserver).ObserveWithExemplar(
v, prometheus.Labels{"dummyID": fmt.Sprint(rand.Intn(100000))}, v, prometheus.Labels{"dummyID": fmt.Sprint(rand.Intn(100000))},
) )
time.Sleep(time.Duration(75*oscillationFactor()) * time.Millisecond) time.Sleep(time.Duration(75*oscillationFactor()) * time.Millisecond)
@ -105,17 +117,19 @@ func main() {
go func() { go func() {
for { for {
v := rand.ExpFloat64() / 1e6 v := rand.ExpFloat64() / 1e6
rpcDurations.WithLabelValues("exponential").Observe(v) m.rpcDurations.WithLabelValues("exponential").Observe(v)
time.Sleep(time.Duration(50*oscillationFactor()) * time.Millisecond) time.Sleep(time.Duration(50*oscillationFactor()) * time.Millisecond)
} }
}() }()
// Expose the registered metrics via HTTP. // Expose the registered metrics via HTTP.
http.Handle("/metrics", promhttp.HandlerFor( http.Handle("/metrics", promhttp.HandlerFor(
prometheus.DefaultGatherer, reg,
promhttp.HandlerOpts{ promhttp.HandlerOpts{
// Opt into OpenMetrics to support exemplars. // Opt into OpenMetrics to support exemplars.
EnableOpenMetrics: true, EnableOpenMetrics: true,
// Pass custom registry
Registry: reg,
}, },
)) ))
log.Fatal(http.ListenAndServe(*addr, nil)) log.Fatal(http.ListenAndServe(*addr, nil))