什么是可观测

相信大家日常经常使用kibana、grafana、jaeger等平台观察系统状态和定位问题，这些就是可观测体系的一部分。可观测主要包括：

日志，实现有ELK(es/logstash/kibana)等
指标，实现有grafana+promthues等
追踪，基于opentracing协议的实现有jaeger、skywalking等

我们排查问题过程，一般都会把三者日志、指标、追踪结合来看，比如通过接口异常增量指标发现问题—>链路追踪定位异常服务—>排查异常服务日志，所以关于可观测我们经常可以看见这个经典的图片：

什么是`OpenTelemetry`

关于可观测除了上述的各种实现外，还有另一套实现OpenCensus，于是诞生统一标准OpenTelemetry且兼容OpenTracing，OpenCensus。不过关于go语言OpenTelemetry的统一sdk实现还不完善，比如目前还不支持日志，具体可以查看https://github.com/open-telemetry/opentelemetry-go。

接下来，我们基于Go来看看，原sdk(也就是未使用OpenTelemetry)接入指标和追踪的方式和基于OpenTelemetry新体系的指标和追踪接入方式区别。

可观测之指标

基于原生`promethues`sdk的指标采集演示

Go版本这里用的1.14

主要依赖的包:

"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promhttp"

就依赖了两个包，使用比较简单：

单独创建一个server使用github.com/prometheus/client_golang/prometheus/promhttp暴露指标
使用github.com/prometheus/client_golang/prometheus创建自定义指标，比如NewCounterVec创建计数器、HistogramVec创建直方图等等。
WithLabelValues给自定义指标打标签

代码示例如下：

docker示例：https://github.com/TIGERB/easy-tips/tree/master/docker/grafana-promethues/go-demo/main.go.promethues

package main

import (
	"net/http"

// 引入prometheus sdk
	"github.com/prometheus/client_golang/prometheus"
	"github.com/prometheus/client_golang/prometheus/promhttp"
)

var (
	// 自定义接口请求次数自定义指标
	GlobalApiCounter *prometheus.CounterVec
)

func init() {
	// 初始化接口请求次数自定义指标
	GlobalApiCounter = prometheus.NewCounterVec(prometheus.CounterOpts{
		Name: "demo_api_request_counter",
		Help: "接口请求次数自定义指标",
	},
		[]string{"domain", "uri"}, // 域名和接口
	)
	prometheus.MustRegister(GlobalApiCounter)
}

func main() {
	go (func() {
		// 创建一个独立的server export暴露Go指标 避免通过业务服务暴露到外网
		metricServer := http.NewServeMux()
		metricServer.Handle("/metrics", promhttp.Handler())
		http.ListenAndServe(":2112", metricServer)
	})()

// 使用默认server
	http.HandleFunc("/v1/demo", func(w http.ResponseWriter, r *http.Request) {
		// 自定义计数
		GlobalApiCounter.WithLabelValues(r.Host, r.RequestURI).Inc()

w.Write([]byte("test"))
	})
	// 启动一个http服务并监听6060端口 这里第二个参数可以指定handler
	http.ListenAndServe(":6060", nil)
}

访问接口curl 127.0.0.1:6060/v1/demo后，查看指标输出 curl 127.0.0.1:2112/metrics，如下：

# HELP demo_api_request_counter 接口请求次数自定义指标
# TYPE demo_api_request_counter counter
demo_api_request_counter{doamin="127.0.0.1:6060",uri="/v1/demo"} 4

基于`OpenTelemetry`sdk的`promethues`指标采集演示

Go版本这里用的1.19 版本太低报错

主要依赖的包:

"github.com/prometheus/client_golang/prometheus/promhttp"
"go.opentelemetry.io/otel/attribute"
"go.opentelemetry.io/otel/exporters/prometheus"
"go.opentelemetry.io/otel/metric"
metricsdk "go.opentelemetry.io/otel/sdk/metric"

相对于原生prome只使用两个包，引入的包多几个：

相同点：仍然单独创建一个server使用github.com/prometheus/client_golang/prometheus/promhttp暴露指标
不同点：使用go.opentelemetry.io/otel/exporters/prometheus初始化一个指标对象meter
不同点：使用meter.Int64Counter初始化计数器、直方图等
不同点：metric.WithAttributes打标签

代码示例如下：

docker示例：https://github.com/TIGERB/easy-tips/tree/master/docker/grafana-promethues/go-demo/main.go

package main

import (
	"context"
	"net/http"

// 引入prometheus sdk
	"github.com/prometheus/client_golang/prometheus/promhttp"
	"go.opentelemetry.io/otel/attribute"
	"go.opentelemetry.io/otel/exporters/prometheus"
	"go.opentelemetry.io/otel/metric"
	metricsdk "go.opentelemetry.io/otel/sdk/metric"
)

var meter metric.Meter

func init() {
	// 初始化指标meter
	mexp, err := prometheus.New()
	if err != nil {
		panic(err)
	}
	meter = metricsdk.NewMeterProvider(metricsdk.WithReader(mexp)).Meter("http-demo")
}

func main() {
	// 集成指标
	// https://github.com/open-telemetry/opentelemetry-go/blob/main/example/prometheus/main.go
	// 创建一个接口访问计数器
	urlCouter, _ := meter.Int64Counter("demo_api_request_counter", metric.WithDescription("QPS"))

go (func() {
		// 创建一个独立的server export暴露Go指标 避免通过业务服务暴露到外网
		metricServer := http.NewServeMux()
		metricServer.Handle("/metrics", promhttp.Handler())
		http.ListenAndServe(":2112", metricServer)
	})()

// 使用默认server
	http.HandleFunc("/v1/demo", func(w http.ResponseWriter, r *http.Request) {
		// 自定义计数
		opt := metric.WithAttributes(attribute.Key("domain").String(r.Host), attribute.Key("uri").String(r.RequestURI))
		urlCouter.Add(context.Background(), 1, opt) // 计数

w.Write([]byte("test"))
	})
	// 启动一个http服务并监听6060端口 这里第二个参数可以指定handler
	http.ListenAndServe(":6060", nil)
}

访问接口curl 127.0.0.1:6060/v1/demo后，查看指标输出 curl 127.0.0.1:2112/metrics，如下：

# HELP demo_api_request_counter_total QPS
# TYPE demo_api_request_counter_total counter
demo_api_request_counter_total{domain="127.0.0.1:6060",otel_scope_name="http-demo",otel_scope_version="",uri="/v1/demo"} 1

可观测之追踪

基于`OpenTracing`sdk的`jaeger`追踪演示

Go版本这里用的1.18

主要依赖的包:

grpc_opentracing "github.com/grpc-ecosystem/go-grpc-middleware/tracing/opentracing"
opentracing "github.com/opentracing/opentracing-go"
jaeger "github.com/uber/jaeger-client-go"
"github.com/uber/jaeger-client-go/transport"

使用方式：

使用jaeger.NewTracer创建一个tracer对象tracer，并指定jaeger服务地址(这里采用的是非agent方式演示)
使用tracer创建一个spantracer.StartSpan，并在你想追踪的代码段后面span.Finish()
这里上游使用grpc服务做测试，使用opentracing中间件SDK go-grpc-middleware/tracing/opentracing

docker示例：https://github.com/TIGERB/easy-tips/tree/master/docker/go-jaeger

package main

import (
	// 导入net/http包
	"context"
	"http-demo/demov1"
	"io"
	"net/http"

"google.golang.org/grpc"

grpc_opentracing "github.com/grpc-ecosystem/go-grpc-middleware/tracing/opentracing"
	opentracing "github.com/opentracing/opentracing-go"
	jaeger "github.com/uber/jaeger-client-go"
	"github.com/uber/jaeger-client-go/transport"
)

var (
	// 创建一个tracer对象
	tracer opentracing.Tracer
)

func main() {
	// 指定上报数据的jaeger服务地址
	sender := transport.NewHTTPTransport(
		"http://go-jaeger-jaeger-demo:14268/api/traces",
	)
	var closer io.Closer
	tracer, closer = jaeger.NewTracer(
		"http-demo",
		jaeger.NewConstSampler(true),
		jaeger.NewRemoteReporter(sender),
	)
	defer closer.Close()

http.HandleFunc("/v1/demo", func(w http.ResponseWriter, r *http.Request) {
		// 创建一个`span`
		span := tracer.StartSpan("demo_span_1")
		defer span.Finish()
		name, err := demoGrpcReq()
		if err != nil {
			w.Write([]byte(err.Error()))
		}
		// 写入响应内容
		w.Write([]byte(name))
	})

// 启动一个http服务并监听6060端口 这里第二个参数可以指定handler
	http.ListenAndServe(":6060", nil)
}

func demoGrpcReq() (string, error) {
	// 使用opentracing中间件SDK go-grpc-middleware/tracing/opentracing
	conn, err := grpc.Dial("grpc-demo:1010", grpc.WithInsecure(), grpc.WithUnaryInterceptor(grpc_opentracing.UnaryClientInterceptor(
		grpc_opentracing.WithTracer(tracer),
	)))
	if err != nil {
		return "", err
	}
	defer conn.Close()

client := demov1.NewGreeterClient(conn)
	resp, err := client.SayHello(context.TODO(), &demov1.HelloRequest{
		Name: "http request",
	})
	if err != nil {
		return "", err
	}
	return resp.GetMessage(), nil
}

使用docker-compose up -d启动演示服务，模拟请求curl 127.0.0.1:6060/v1/demo，查看jaeger后台http://localhost:16686/，示例如下：

基于`OpenTelemetry`sdk的`jaeger`追踪演示

Go版本这里用的1.19 版本太低报错

主要依赖的包:

elemetry.io/contrib/instrumentation/net/http/otelhttp"
"google.golang.org/grpc"

"go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc"
"go.opentelemetry.io/otel"
"go.opentelemetry.io/otel/exporters/jaeger"
"go.opentelemetry.io/otel/propagation"
"go.opentelemetry.io/otel/sdk/resource"
tracesdk "go.opentelemetry.io/otel/sdk/trace"
semconv "go.opentelemet

使用方式：

使用"go.opentelemetry.io/otel/exporters/jaeger"初始化追踪tracer，同样指定jaeger服务地址(这里采用的是非agent方式演示)
http服务进行链路追踪，使用包go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp.NewHandler创建http handler
grpc服务进行链路追踪，使用grpc otel追踪sdk go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc

docker示例：https://github.com/TIGERB/easy-tips/tree/master/docker/go-otel

package main

import (
	// 导入net/http包
	"context"
	"http-demo/demov1"
	"net/http"

"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
	"google.golang.org/grpc"

"go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc"
	"go.opentelemetry.io/otel"
	"go.opentelemetry.io/otel/exporters/jaeger"
	"go.opentelemetry.io/otel/propagation"
	"go.opentelemetry.io/otel/sdk/resource"
	tracesdk "go.opentelemetry.io/otel/sdk/trace"
	semconv "go.opentelemetry.io/otel/semconv/v1.17.0"
)

// 追踪
var tracer *tracesdk.TracerProvider

func init() {
	// 初始化追踪tracer
	// https://github.com/open-telemetry/opentelemetry-go/blob/main/example/jaeger/main.go
	// Create the Jaeger exporter
	exp, err := jaeger.New(jaeger.WithCollectorEndpoint(jaeger.WithEndpoint("http://jaeger-demo:14268/api/traces")))
	if err != nil {
		panic(err)
		return
	}
	tracer = tracesdk.NewTracerProvider(
		tracesdk.WithBatcher(exp),
		tracesdk.WithResource(resource.NewWithAttributes(
			semconv.SchemaURL,
			semconv.ServiceNameKey.String("http-demo"),
		)),
	)

}

// 常见框架集成opentelemetry SDK
// https://github.com/open-telemetry/opentelemetry-go-contrib/tree/main/instrumentation
func main() {
	otel.SetTracerProvider(tracer)
    // 关联上下文
	otel.SetTextMapPropagator(propagation.NewCompositeTextMapPropagator(propagation.TraceContext{}, propagation.Baggage{}))
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()
	defer tracer.Shutdown(ctx)

// /v1/demo接口 业务逻辑handler
	demoHandler := func(w http.ResponseWriter, r *http.Request) {
		// 调用demo grpc接口
		name, err := demoGrpcReq()
		if err != nil {
			w.Write([]byte(err.Error()))
		}
		// 写入响应内容
		w.Write([]byte(name))
	}

// 集成链路追踪
	// https://github.com/open-telemetry/opentelemetry-go-contrib/blob/main/instrumentation/net/http/otelhttp/example/server/server.go
	otelHandler := otelhttp.NewHandler(http.HandlerFunc(demoHandler), "otelhttp demo test")
	http.Handle("/v1/demo", otelHandler)

// 启动一个http服务并监听6060端口 这里第二个参数可以指定handler
	http.ListenAndServe(":6060", nil)
}

func demoGrpcReq() (string, error) {
	// 使用grpc otel追踪sdk go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc
	conn, err := grpc.Dial("grpc-demo:1010",
		grpc.WithInsecure(),
		grpc.WithUnaryInterceptor(otelgrpc.UnaryClientInterceptor()),
		grpc.WithStreamInterceptor(otelgrpc.StreamClientInterceptor()),
	)
	if err != nil {
		return "", err
	}
	defer conn.Close()

client := demov1.NewGreeterClient(conn)
	resp, err := client.SayHello(context.TODO(), &demov1.HelloRequest{
		Name: "http request",
	})
	if err != nil {
		return "", err
	}
	return resp.GetMessage(), nil
}

使用docker-compose up -d启动演示服务，模拟请求curl 127.0.0.1:6060/v1/demo，查看jaeger后台http://localhost:16686/，示例如下：

一探究竟新一代可观测标准OpenTelemetry

什么是可观测

什么是`OpenTelemetry`

可观测之指标

基于原生`promethues`sdk的指标采集演示

基于`OpenTelemetry`sdk的`promethues`指标采集演示

可观测之追踪

基于`OpenTracing`sdk的`jaeger`追踪演示

基于`OpenTelemetry`sdk的`jaeger`追踪演示

Recommend

Using GitHub Actions to Deploy a FastAPI Project to Heroku

Optimising platform spend with cluster autoscaling

Invalid at computed-value time

How to Create an Overpowered Blog With Hugo (As a Wordpress Alternative) | Somra...

AI孙燕姿爆火，谁先坐不住了？

Dutch startup targets European intercity air taxi service from 2027

借助NVIDIA BlueField 系列 DPU提升数据中心能效

6月必打卡｜Usee设计艺术节超全剧透！

快手×房东的猫：好风吹进生活里

我只用2天，从小白变成行业专家

About Joyk

一探究竟新一代可观测标准OpenTelemetry

什么是可观测

什么是OpenTelemetry

可观测之指标

基于原生promethuessdk的指标采集演示

基于OpenTelemetrysdk的promethues指标采集演示

可观测之追踪

基于OpenTracingsdk的jaeger追踪演示

基于OpenTelemetrysdk的jaeger追踪演示

Recommend

About Joyk

什么是`OpenTelemetry`

基于原生`promethues`sdk的指标采集演示

基于`OpenTelemetry`sdk的`promethues`指标采集演示

基于`OpenTracing`sdk的`jaeger`追踪演示

基于`OpenTelemetry`sdk的`jaeger`追踪演示