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动手写prometheus的exporter-02-Counter（计数器）

2022-08-10 05:16:00 【开发运维玄德公】

文章目录

概述
1. 不带标签的Counter
2. 带标签的Counter

概述

特点：只增不减（除非系统发生重启，或者用户进程有异常）。

常见的监控指标如http_requests_total, node_cpu都是Counter类型的监控指标。

标记：一般以_total作为后缀。

1. 不带标签的Counter

1.1 定义指标

语法

实例化

func NewCounter(opts CounterOpts) Counter

CounterOpts类型

type CounterOpts Opts

Opts结构体

type Opts struct {
    
    Namespace   string
    Subsystem   string
    Name        string
    Help        string
    ConstLabels Labels
}

完整示例

代码

package main

import (
	"flag"
	"github.com/prometheus/client_golang/prometheus"
	"github.com/prometheus/client_golang/prometheus/promhttp"
	"log"
	"net/http"
	"time"
)

var addr = flag.String("listen-address", ":1840", "The address to listen on for HTTP requests")

var (
	numOfBuns = prometheus.NewCounter(prometheus.CounterOpts{
    
		Namespace: "xi_shu",
		Subsystem: "jing_zhou_team",
		Name:      "guanyu_eaten_num_all",
		Help:      "Number of steamed buns eaten by Guan Yu",
	})
)

func init() {
    
	prometheus.MustRegister(numOfBuns)
}

func main() {
    
	flag.Parse()
	http.Handle("/metrics", promhttp.Handler())
	log.Fatal(http.ListenAndServe(*addr, nil))
}

结果显示

# HELP xi_shu_jing_zhou_team_guanyu_eaten_num Number of steamed buns eaten by Guan Yu
# TYPE xi_shu_jing_zhou_team_guanyu_eaten_num counter
xi_shu_jing_zhou_team_guanyu_eaten_num_all 0

1.2 获取数据

语法

Add() 增加N

func (Counter) Add(float64)

Inc() 增加1

func (Counter) Inc()

完整示例

package main

import (
	"flag"
	"github.com/prometheus/client_golang/prometheus"
	"github.com/prometheus/client_golang/prometheus/promhttp"
	"log"
	"net/http"
	"time"
)
var addr = flag.String("listen-address", ":1840", "The address to listen on for HTTP requests")

var (
	numOfBuns = prometheus.NewCounter(prometheus.CounterOpts{
    
		Namespace: "xi_shu",
		Subsystem: "jing_zhou_team",
		Name:      "guanyu_eaten_num_all",
		Help:      "Number of steamed buns eaten by Guan Yu",
	})
)

func init() {
    
	prometheus.MustRegister(numOfBuns)
}

func main() {
    
	flag.Parse()
	go func() {
    
		for true {
    
			numOfBuns.Add(2)
			time.Sleep(time.Second)
		}
	}()
	http.Handle("/metrics", promhttp.Handler())
	log.Fatal(http.ListenAndServe(*addr, nil))
}

结果显示

# HELP xi_shu_jing_zhou_team_guanyu_eaten_num_all Number of steamed buns eaten by Guan Yu
# TYPE xi_shu_jing_zhou_team_guanyu_eaten_num_all counter
xi_shu_jing_zhou_team_guanyu_eaten_num_all 74

2. 带标签的Counter

2.1 定义指标

语法

实例化

func NewCounterVec(opts CounterOpts, labelNames []string) *CounterVec

CounterOpts类型

type CounterOpts Opts

Opts结构体

type Opts struct {
    
    Namespace   string
    Subsystem   string
    Name        string
    Help        string
    ConstLabels Labels
}

完整示例

package main

import (
	"flag"
	"github.com/prometheus/client_golang/prometheus"
	"github.com/prometheus/client_golang/prometheus/promhttp"
	"log"
	"net/http"
	"time"
)
var addr = flag.String("listen-address", ":1840", "The address to listen on for HTTP requests")

var (
	numOfBuns = prometheus.NewCounterVec(prometheus.CounterOpts{
    
		Namespace: "xi_shu",
		Subsystem: "jing_zhou_team",
		Name:      "eaten_num_all",
		Help:      "Number of steamed buns eaten by Guan Yu",
	},[]string{
    "name","age"})
)

func init() {
    
	prometheus.MustRegister(numOfBuns)
}

func main() {
    
	flag.Parse()
	http.Handle("/metrics", promhttp.Handler())
	log.Fatal(http.ListenAndServe(*addr, nil))
}

输出
带标签的指标，没有打标签之前，不会显示。

2.2 获取数据

语法

Add() 增加N

func (Counter) Add(float64)

Inc() 增加1

func (Counter) Inc()

完整示例

代码

package main

import (
	"flag"
	"github.com/prometheus/client_golang/prometheus"
	"github.com/prometheus/client_golang/prometheus/promhttp"
	"log"
	"net/http"
	"time"
)
var addr = flag.String("listen-address", ":1840", "The address to listen on for HTTP requests")

var (
	numOfBuns = prometheus.NewCounterVec(prometheus.CounterOpts{
    
		Namespace: "xi_shu",
		Subsystem: "jing_zhou_team",
		Name:      "eaten_num_all",
		Help:      "Number of steamed buns eaten by Guan Yu",
	},[]string{
    "name","age"})
)

func init() {
    
	prometheus.MustRegister(numOfBuns)
}

func main() {
    
	flag.Parse()
	go func() {
    
		for true {
    
			numOfBuns.WithLabelValues("guan_yu","25").Add(2)
			numOfBuns.WithLabelValues("zhang_fei","22").Add(3)
			time.Sleep(time.Second)
		}
	}()
	http.Handle("/metrics", promhttp.Handler())
	log.Fatal(http.ListenAndServe(*addr, nil))
}

显示结果

# HELP xi_shu_jing_zhou_team_eaten_num Number of steamed buns eaten by Guan Yu
# TYPE xi_shu_jing_zhou_team_eaten_num gauge
xi_shu_jing_zhou_team_eaten_num{
    age="22",name="zhang_fei"} 33
xi_shu_jing_zhou_team_eaten_num{
    age="25",name="guan_yu"} 22