OpenTelemetry Java
使用 OpenTelemetry 时，请先完成 OpenTelemetry 输入配置，再选择下文方式之一接入 Java。
Java Agent 方式¶
最常用的是 Java Agent 自动埋点，启动方式可分为三类。
1) 环境变量¶
export JAVA_OPTS="-javaagent:/path/to/opentelemetry-javaagent.jar"
export OTEL_TRACES_EXPORTER=otlp
export OTEL_EXPORTER_OTLP_ENDPOINT="http://127.0.0.1:4317"
export OTEL_SERVICE_NAME=service-name
2) 命令行启动¶
java -javaagent:/path/to/opentelemetry-javaagent.jar \
-Dotel.traces.exporter=otlp \
-Dotel.exporter.otlp.endpoint=http://127.0.0.1:4317 \
-Dotel.service.name=service-name \
-jar your-server.jar
3) Tomcat 配置¶
cd <tomcat 安装目录>/bin
vim catalina.sh
# 在 CATALINA_OPTS 中增加
CATALINA_OPTS="$CATALINA_OPTS -javaagent:/path/to/opentelemetry-javaagent.jar -Dotel.traces.exporter=otlp -Dotel.service.name=service-name"; export CATALINA_OPTS
如果 DataKit 与应用在同主机，且使用默认端口，可不设置
OTEL_EXPORTER_OTLP_ENDPOINT（默认http://localhost:4317）。
如果使用 OTEL Agent V2 的 HTTP transport，需要设置：-Dotel.exporter.otlp.protocol=http/protobuf，并为 traces/metrics/logs 配置各自 endpoint（例如 /otel/v1/...）。
代码方式接入¶
如果不适合自动埋点，可通过代码方式集成 OTEL SDK。
Maven 依赖示例：
<dependency>
<groupId>io.opentelemetry</groupId>
<artifactId>opentelemetry-sdk</artifactId>
<version>1.9.0</version>
</dependency>
<dependency>
<groupId>io.opentelemetry</groupId>
<artifactId>opentelemetry-exporter-otlp</artifactId>
<version>1.9.0</version>
</dependency>
<dependency>
<groupId>io.opentelemetry</groupId>
<artifactId>opentelemetry-semconv</artifactId>
<version>1.9.0-alpha</version>
</dependency>
<dependency>
<groupId>io.grpc</groupId>
<artifactId>grpc-netty-shaded</artifactId>
<version>1.41.0</version>
</dependency>
<dependency>
<groupId>io.grpc</groupId>
<artifactId>grpc-protobuf</artifactId>
<version>1.36.1</version>
</dependency>
示例代码：
package com.example;
import io.opentelemetry.api.OpenTelemetry;
import io.opentelemetry.api.common.Attributes;
import io.opentelemetry.api.trace.Span;
import io.opentelemetry.api.trace.Tracer;
import io.opentelemetry.api.trace.propagation.W3CTraceContextPropagator;
import io.opentelemetry.context.Context;
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.semconv.resource.attributes.ResourceAttributes;
import io.opentelemetry.sdk.trace.SdkTracerProvider;
import io.opentelemetry.sdk.trace.export.BatchSpanProcessor;
import java.util.concurrent.TimeUnit;
import static java.lang.Thread.sleep;
public class otlpdemo {
public static void main(String[] args) {
try {
OtlpGrpcSpanExporter grpcSpanExporter = OtlpGrpcSpanExporter.builder()
.setEndpoint("http://127.0.0.1:4317")
.setTimeout(2, TimeUnit.SECONDS)
.build();
SdkTracerProvider tracerProvider = SdkTracerProvider.builder()
.addSpanProcessor(BatchSpanProcessor.builder(grpcSpanExporter).build())
.setResource(Resource.create(Attributes.builder()
.put(ResourceAttributes.SERVICE_NAME, "serviceForJAVA")
.put(ResourceAttributes.SERVICE_VERSION, "1.0.0")
.put(ResourceAttributes.HOST_NAME, "host")
.build()))
.build();
OpenTelemetry openTelemetry = OpenTelemetrySdk.builder()
.setTracerProvider(tracerProvider)
.setPropagators(ContextPropagators.create(W3CTraceContextPropagator.getInstance()))
.buildAndRegisterGlobal();
Tracer tracer = openTelemetry.getTracer("instrumentation-library-name", "1.0.0");
Span parentSpan = tracer.spanBuilder("parent").startSpan();
Span childSpan = tracer.spanBuilder("child")
.setParent(Context.current().with(parentSpan))
.startSpan();
childSpan.setAttribute("tagsA", "example");
sleep(500);
for (int i = 0; i < 10; i++) {
Span childSpan1 = tracer.spanBuilder("child")
.setParent(Context.current().with(parentSpan))
.startSpan();
sleep(1000);
System.out.println(i);
childSpan1.end();
}
childSpan.end();
childSpan.end(0, TimeUnit.NANOSECONDS);
System.out.println("span end");
sleep(1000);
parentSpan.end();
tracerProvider.shutdown();
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
System.out.println("finally end");
}
}
}