通过OpenTelemetry Java Agent接入APM

华为云APM兼容OpenTelemetry协议，支持直接接收通过OpenTelemetry SDK或Agent上报的链路追踪数据。本文将介绍如何通过OpenTelemetry Java Agent实现无侵入式埋点，或通过SDK进行手动埋点，并将链路数据对接到APM。

示例demo

使用springboot实现一个简单掷骰子应用。

编写业务代码，初始化一个springboot项目。

创建RollDice.java文件，内容如下：

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import java.util.Optional;
import java.util.concurrent.ThreadLocalRandom;

@RestController
public class RollDice {

    @GetMapping("/rolldice")
    public String rollDiceAndSave(@RequestParam("player") Optional<String> player) {
        int result = 0;
        //掷骰子
        try {
            Thread.sleep(100);
            result = ThreadLocalRandom.current().nextInt(1, 7);
        } catch (InterruptedException e) {
            Thread.currentThread().interrupt();
        }
        saveResult(player.orElse("Anonymous player"), result);

        return Integer.toString(result);
    }

    private void saveResult(String player, int dicePoint) {
        //模拟数据库操作耗时
        try {
            Thread.sleep(100);
        } catch (InterruptedException e) {
            Thread.currentThread().interrupt();
        }
    }
}

application.properties 内容如下：

server.port=8080

启动。

java -jar otel-demo-0.0.1-SNAPSHOT.jar & 
curl http://localhost:8080/rolldice?player=Alex

使用Java agent自动埋点

OpenTelemetry java agent 支持对一些常用库/框架进行无侵入埋点方式，详情参考自动埋点支持的库/框架。

获取探针。

添加探针启动参数并重启应用。添加启动命令并重启应用，命令格式如下：

java -javaagent:探针安装路径  \
  -Dotel.exporter.otlp.protocol=grpc  \
  -Dotel.exporter.otlp.traces.endpoint=上报地址 \
  -Dotel.exporter.otlp.headers=Authentication=鉴权信息  \
  -Dotel.service.name=应用名称.组件名称.环境名称  \  
  -Dotel.metrics.exporter=none  \
  -Dotel.logs.exporter=none  \
  -jar <yourApp>.jar  &

curl http://localhost:8080/rolldice?player=Alex

登录APM控制台。
单击左侧，选择“管理与监管> 应用性能管理 APM”，进入APM服务页面。
在左侧导航栏选择“链路追踪 > 指标”。
在界面左侧树单击环境，单击“概览”，切换至概览页签，在概览页签可以查看该实例的应用监控数据。详细操作参见指标

使用Java SDK手动埋点

当自动埋点不满足业务场景，或者需要自定义业务埋点逻辑时，可以引入OpenTelemetry SDK 进行手动埋点。

添加Maven依赖。

在pom.xml中引入OpenTelemetry相关依赖

<dependencies>
        <dependency>
            <groupId>io.opentelemetry</groupId>
            <artifactId>opentelemetry-api</artifactId>
        </dependency>
        <dependency>
            <groupId>io.opentelemetry</groupId>
            <artifactId>opentelemetry-sdk-trace</artifactId>
        </dependency>
        <dependency>
            <groupId>io.opentelemetry</groupId>
            <artifactId>opentelemetry-exporter-otlp</artifactId>
        </dependency>
        <dependency>
            <groupId>io.opentelemetry</groupId>
            <artifactId>opentelemetry-sdk</artifactId>
        </dependency>
        <dependency>
            <groupId>io.opentelemetry</groupId>
            <artifactId>opentelemetry-semconv</artifactId>
            <version>1.30.0-alpha</version>
        </dependency>
    </dependencies>
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>io.opentelemetry</groupId>
                <artifactId>opentelemetry-bom</artifactId>
                <version>1.30.0</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

初始化 OpenTelemetry SDK。

编写一个工具类，用于配置和创建 OpenTelemetry实例。

import io.opentelemetry.api.OpenTelemetry;
import io.opentelemetry.api.common.Attributes;
import io.opentelemetry.api.trace.Tracer;
import io.opentelemetry.api.trace.propagation.W3CTraceContextPropagator;
import io.opentelemetry.context.propagation.ContextPropagators;
import io.opentelemetry.exporter.otlp.trace.OtlpGrpcSpanExporter;
import io.opentelemetry.sdk.OpenTelemetrySdk;
import io.opentelemetry.sdk.resources.Resource;
import io.opentelemetry.sdk.trace.SdkTracerProvider;
import io.opentelemetry.sdk.trace.export.BatchSpanProcessor;
import io.opentelemetry.semconv.resource.attributes.ResourceAttributes;

public class OpenTelemetrySupport {

    static {
        // 获取OpenTelemetry Tracer
        Resource resource = Resource.getDefault()
            .merge(Resource.create(Attributes.of(ResourceAttributes.SERVICE_NAME, "应用名称.组件名称.环境名称", // 应用名称需在APM链路追踪创建一个opentelemetry的应用，组件名称和环境名称任意填写
                ResourceAttributes.SERVICE_VERSION, "1.0.0", // 版本号。
                ResourceAttributes.DEPLOYMENT_ENVIRONMENT, "test", // 部署环境，任意填写字符串。
                ResourceAttributes.HOST_NAME, "127.0.0.1" // 请将 ${host-name} 替换为您的主机名，也任意填写字符串。
            )));

        SdkTracerProvider sdkTracerProvider = SdkTracerProvider.builder()
            .addSpanProcessor(BatchSpanProcessor.builder(
                OtlpGrpcSpanExporter.builder().setEndpoint("接入地址") // 接入地址
                    .addHeader("Authentication", "应用鉴权信息") // 应用鉴权信息 
                    .build()).build())
            .setResource(resource)
            .build();

        OpenTelemetry openTelemetry = OpenTelemetrySdk.builder()
            .setTracerProvider(sdkTracerProvider)
            .setPropagators(ContextPropagators.create(W3CTraceContextPropagator.getInstance()))
            .buildAndRegisterGlobal();

        tracer = openTelemetry.getTracer("OpenTelemetry Tracer", "1.0.0");
    }

    private static Tracer tracer;

    public static Tracer getTracer() {
        return tracer;
    }
}

创建Span。

import io.opentelemetry.api.common.Attributes;
import io.opentelemetry.api.trace.Span;
import io.opentelemetry.api.trace.SpanKind;
import io.opentelemetry.api.trace.StatusCode;
import io.opentelemetry.context.Scope;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import java.util.Optional;
import java.util.concurrent.ThreadLocalRandom;

@RestController
public class RollDice {

    @GetMapping("/rolldice")
    public String rollDiceAndSave(@RequestParam("player") Optional<String> player) {
        int result = 0;
        Span span = OpenTelemetrySupport.getTracer().spanBuilder("rolldice").setSpanKind(SpanKind.SERVER).startSpan();
        try (Scope scope = span.makeCurrent()) {
            span.setStatus(StatusCode.OK);
            span.setAttribute("dice.player", player.orElse("Anonymous player"));
            span.addEvent("ev",
                Attributes.builder().put("event1", "value1").build());  // 调用链的span详情页面上会显示后面的event1和value1
            span.setAttribute("http.target", "rolldice");   // 作为server类型，必须设置该字段
            span.setAttribute("http.method", "GET");  // 作为server类型，必须设置该字段
            span.setAttribute("http.route", "{path}/**");  // 可选字段
            span.setAttribute("http.status_code", 200);  // 可选字段
            Attributes attributes = Attributes.builder()
                .put("exception.type", "NullPoint")
                .put("exception.message", "I am exception message")
                .build();   // 可选字段，展示在调用链的span详情页面上
            span.addEvent("exception", attributes);
            //掷骰子
            try {
                Thread.sleep(100);
                result = ThreadLocalRandom.current().nextInt(1, 7);
            } catch (InterruptedException e) {
                Thread.currentThread().interrupt();
            }
            saveResult(player.orElse("Anonymous player"), result);
        } catch (Throwable t) {
            span.setStatus(StatusCode.ERROR, "handle parent span error");
        } finally {
            span.end();
        }
        return Integer.toString(result);
    }

    private void saveResult(String player, int dicePoint) {
        Span span = OpenTelemetrySupport.getTracer()
            .spanBuilder("saveResult")
            .setSpanKind(SpanKind.CLIENT)
            .startSpan();  // 数据库调用类型的span，必须设置为client类型，setParent这一步用于设置父span，标识父子span的关系，用以构造span的树桩结构

        try (Scope scope = span.makeCurrent()) {
            span.setAttribute("db.system", "mysql"); // 数据库调用类型的span，必须设置为db.system类型，用来标识数据库的类型
            span.setAttribute("db.statement",
                "INSERT INTO dice_roll (player_name, dice_point) VALUES (" + player + ", " + dicePoint
                    + ")"); // 数据库调用类型的span，必须设置为db.statement，用来标识数据库的SQL语句
            span.setAttribute("db.connection_string",
                "127.0.0.1:3306:mysql"); // 数据库调用类型的span，必须设置为db.connection_string，用来标识数据库的连接对象

            //模拟数据库操作耗时
            try {
                Thread.sleep(100);
            } catch (InterruptedException e) {
                Thread.currentThread().interrupt();
            }
        } catch (Throwable t) {
            span.recordException(t);
            span.setStatus(StatusCode.ERROR, "handle child span error");
        } finally {
            span.end();
        }
    }
}