Merge pull request #1152 from jessicalins/update-to-custom-reg

Update examples to use custom registry
This commit is contained in:
Kemal Akkoyun 2022-10-26 10:15:58 -04:00 committed by GitHub
commit 0859bb8f37
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3 changed files with 86 additions and 54 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))

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@ -19,6 +19,7 @@ import (
"log" "log"
"net/http" "net/http"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promhttp" "github.com/prometheus/client_golang/prometheus/promhttp"
) )
@ -26,6 +27,11 @@ var addr = flag.String("listen-address", ":8080", "The address to listen on for
func main() { func main() {
flag.Parse() flag.Parse()
http.Handle("/metrics", promhttp.Handler())
// Create non-global registry.
reg := prometheus.NewRegistry()
// Expose /metrics HTTP endpoint using the created custom registry.
http.Handle("/metrics", promhttp.HandlerFor(reg, promhttp.HandlerOpts{Registry: reg}))
log.Fatal(http.ListenAndServe(*addr, nil)) log.Fatal(http.ListenAndServe(*addr, nil))
} }

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@ -35,39 +35,51 @@
// "github.com/prometheus/client_golang/prometheus/promhttp" // "github.com/prometheus/client_golang/prometheus/promhttp"
// ) // )
// //
// var ( // type metrics struct {
// cpuTemp = prometheus.NewGauge(prometheus.GaugeOpts{ // cpuTemp prometheus.Gauge
// hdFailures *prometheus.CounterVec
// }
//
// func NewMetrics(reg prometheus.Registerer) *metrics {
// m := &metrics{
// cpuTemp: prometheus.NewGauge(prometheus.GaugeOpts{
// Name: "cpu_temperature_celsius", // Name: "cpu_temperature_celsius",
// Help: "Current temperature of the CPU.", // Help: "Current temperature of the CPU.",
// }) // }),
// hdFailures = prometheus.NewCounterVec( // hdFailures: prometheus.NewCounterVec(
// prometheus.CounterOpts{ // prometheus.CounterOpts{
// Name: "hd_errors_total", // Name: "hd_errors_total",
// Help: "Number of hard-disk errors.", // Help: "Number of hard-disk errors.",
// }, // },
// []string{"device"}, // []string{"device"},
// ) // ),
// ) // }
// // reg.MustRegister(m.cpuTemp)
// func init() { // reg.MustRegister(m.hdFailures)
// // Metrics have to be registered to be exposed: // return m
// prometheus.MustRegister(cpuTemp)
// prometheus.MustRegister(hdFailures)
// } // }
// //
// func main() { // func main() {
// cpuTemp.Set(65.3) // // Create a non-global registry.
// hdFailures.With(prometheus.Labels{"device":"/dev/sda"}).Inc() // reg := prometheus.NewRegistry()
// //
// // The Handler function provides a default handler to expose metrics // // Create new metrics and register them using the custom registry.
// // via an HTTP server. "/metrics" is the usual endpoint for that. // m := NewMetrics(reg)
// http.Handle("/metrics", promhttp.Handler()) // // Set values for the new created metrics.
// m.cpuTemp.Set(65.3)
// m.hdFailures.With(prometheus.Labels{"device":"/dev/sda"}).Inc()
//
// // Expose metrics and custom registry via an HTTP server
// // using the HandleFor function. "/metrics" is the usual endpoint for that.
// http.Handle("/metrics", promhttp.HandlerFor(reg, promhttp.HandlerOpts{Registry: reg}))
// log.Fatal(http.ListenAndServe(":8080", nil)) // log.Fatal(http.ListenAndServe(":8080", nil))
// } // }
// //
// //
// This is a complete program that exports two metrics, a Gauge and a Counter, // This is a complete program that exports two metrics, a Gauge and a Counter,
// the latter with a label attached to turn it into a (one-dimensional) vector. // the latter with a label attached to turn it into a (one-dimensional) vector.
// It register the metrics using a custom registry and exposes them via an HTTP server
// on the /metrics endpoint.
// //
// Metrics // Metrics
// //