GoManila Cardinality Demo

main.go

package main

import (
	//"github.com/google/uuid"
	"github.com/prometheus/client_golang/prometheus"
	"github.com/prometheus/client_golang/prometheus/promhttp"
	"math/rand"
	"net/http"
	"time"
)

var (
	randSource        = rand.NewSource(time.Now().UnixNano())
	randGen           = rand.New(randSource)
	methods           = []string{"GET", "POST", "PUT", "PATCH"}
	paths             = []string{"/foo", "/bar", "/baz"}
	status            = []string{"200", "400", "500"}
	httpRequestsTotal = prometheus.NewCounterVec(
		prometheus.CounterOpts{
			Name: "myapp_http_requests_total",
			Help: "The total number of http requests",
		},
		[]string{"method", "path", "status"},
	)
)

func recordMetrics() {
	go func() {
		for {
			for i := 0; i < 1000; i++ {
				m := methods[randGen.Intn(len(methods))]
				p := paths[randGen.Intn(len(paths))]
				s := status[randGen.Intn(len(status))]
				httpRequestsTotal.With(prometheus.Labels{
					"method": m,
					"path":   p,
					"status": s,
				}).Inc()
			}

			time.Sleep(1 * time.Second)
		}
	}()
}

func main() {
	prometheus.MustRegister(httpRequestsTotal)
	recordMetrics()

	http.Handle("/metrics", promhttp.Handler())
	http.ListenAndServe(":2112", nil)
}

main2.go

package main

import (
	"github.com/google/uuid"
	"github.com/prometheus/client_golang/prometheus"
	"github.com/prometheus/client_golang/prometheus/promhttp"
	"math/rand"
	"net/http"
	"time"
)

var (
	randSource        = rand.NewSource(time.Now().UnixNano())
	randGen           = rand.New(randSource)
	methods           = []string{"GET", "POST", "PUT", "PATCH"}
	paths             = []string{"/foo", "/bar", "/baz"}
	status            = []string{"200", "400", "500"}
	httpRequestsTotal = prometheus.NewCounterVec(
		prometheus.CounterOpts{
			Name: "myapp_http_requests_total",
			Help: "The total number of http requests",
		},
		[]string{"method", "path", "status", "user_id"},
	)
)

func recordMetrics() {
	go func() {
		for {
			for i := 0; i < 1000; i++ {
				m := methods[randGen.Intn(len(methods))]
				p := paths[randGen.Intn(len(paths))]
				s := status[randGen.Intn(len(status))]
				httpRequestsTotal.With(prometheus.Labels{
					"method":  m,
					"path":    p,
					"status":  s,
					"user_id": uuid.New().String(),
				}).Inc()
			}

			time.Sleep(1 * time.Second)
		}
	}()
}

func main() {
	prometheus.MustRegister(httpRequestsTotal)
	recordMetrics()

	http.Handle("/metrics", promhttp.Handler())
	http.ListenAndServe(":2112", nil)
}

prometheus.yml

# my global config
global:
  scrape_interval:     5s # Set the scrape interval to every 15 seconds. Default is every 1 minute.
  evaluation_interval: 5s # Evaluate rules every 15 seconds. The default is every 1 minute.
  # scrape_timeout is set to the global default (10s).

# Alertmanager configuration
alerting:
  alertmanagers:
  - static_configs:
    - targets:
      # - alertmanager:9093

# Load rules once and periodically evaluate them according to the global 'evaluation_interval'.
rule_files:
  # - "first_rules.yml"
  # - "second_rules.yml"

# A scrape configuration containing exactly one endpoint to scrape:
# Here it's Prometheus itself.
scrape_configs:
  # The job name is added as a label `job=<job_name>` to any timeseries scraped from this config.
  - job_name: 'prometheus'

    # metrics_path defaults to '/metrics'
    # scheme defaults to 'http'.

    static_configs:
    - targets: ['localhost:9090']
  - job_name: 'promthing'
    scrape_interval: 5s
    static_configs:
    - targets: ['localhost:2112']