opnetelemetry-jaeger

可观测性 opentelemetry

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 2022/12/03 

在调研中，持续更新本篇 …

架构

Tracing

核心概念

此处只介绍使用中会遇到的概念，具体细节请查阅文档

API

TracerProvider 提供访问 Tracer 的入口。作为一个池子放置和管理 Tracers
Span Exporter 定义一系列接口，执行 telemetry data 的序列化与反序列化，以将数据提交到不同的 backend。

应用

Tracing

根据其架构设计，所有的应用都可以实现为：

定义 Resource
创建 Provider
设置全局 Provider (option)
设置 Exporter (option)
server 中使用 Tracing

Python

from opentelemetry import trace
from opentelemetry.exporter.jaeger.thrift import JaegerExporter
from opentelemetry.sdk.resources import SERVICE_NAME, Resource
from opentelemetry.sdk.trace import TracerProvider
from opentelemetry.sdk.trace.export import BatchSpanProcessor

from opentelemetry.propagate import set_global_textmap
from opentelemetry.propagators.jaeger import JaegerPropagator

APP_NAME = "app"

def init():
    init_provider()

    set_global_textmap(JaegerPropagator())

def init_provider():

    trace.set_tracer_provider(
        TracerProvider(
            resource=Resource.create({SERVICE_NAME: APP_NAME})
        )
    )

    jaeger_exporter = JaegerExporter()
    trace.get_tracer_provider().add_span_processor(
        BatchSpanProcessor(jaeger_exporter)
    )

常用的 package 如 Flask, Django, FastAPI, psycopg2 等都有提供 instrument, 实现基于AOP的注入。

Golang

import (
    "go.opentelemetry.io/otel"
    "go.opentelemetry.io/otel/exporters/jaeger"
    "go.opentelemetry.io/otel/sdk/resource"
    sdktrace "go.opentelemetry.io/otel/sdk/trace"
    semconv "go.opentelemetry.io/otel/semconv/v1.10.0"
    jaegerpropagator "go.opentelemetry.io/contrib/propagators/jaeger"
)

const APP_NAME := "app"

func InitGlobalProvider() *sdktrace.TracerProvider {
    p, e := tracerProvider()
    if e != nil {
        return nil
    }

    otel.SetTracerProvider(p)

    return p
}

func tracerProvider(url string) (*sdktrace.TracerProvider, error) {
    serviceName := APP_NAME

    exp, err := jaeger.New(jaeger.WithAgentEndpoint())
    if err != nil {
        return nil, err
    }

    tp := sdktrace.NewTracerProvider(
        // Always be sure to batch in production.
        sdktrace.WithBatcher(exp),
        // Record information about this application in a Resource.
        sdktrace.WithResource(resource.NewWithAttributes(
            semconv.SchemaURL,
            semconv.ServiceNameKey.String(serviceName),
        )),
    )
    return tp, nil
}

func InitGlobalPropagator() propagation.TextMapPropagator {
    otel.SetTextMapPropagator(jaegerpropagator.Jaeger{})
}