Quarkus fails to start up if I set `quarkus.otel.traces.exporter=otlp`

[LarsSven]

Describe the bug

When setting quarkus.otel.traces.exporter=otlp, Quarkus fails with:

2025-06-24 13:05:33,711 ERROR [io.qua.run.Application] (Quarkus Main Thread) Failed to start application: java.lang.RuntimeException: Failed to start quarkus
	at io.quarkus.runner.ApplicationImpl.doStart(Unknown Source)
	at io.quarkus.runtime.Application.start(Application.java:101)
	at io.quarkus.runtime.ApplicationLifecycleManager.run(ApplicationLifecycleManager.java:119)
	at io.quarkus.runtime.Quarkus.run(Quarkus.java:80)
	at io.quarkus.runtime.Quarkus.run(Quarkus.java:51)
	at io.quarkus.runtime.Quarkus.run(Quarkus.java:144)
	at io.quarkus.runner.GeneratedMain.main(Unknown Source)
	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
	at java.base/java.lang.reflect.Method.invoke(Method.java:580)
	at io.quarkus.runner.bootstrap.StartupActionImpl$1.run(StartupActionImpl.java:121)
	at java.base/java.lang.Thread.run(Thread.java:1583)
Caused by: java.lang.NoClassDefFoundError: okhttp3/Callback
	at io.opentelemetry.exporter.sender.okhttp.internal.OkHttpGrpcSenderProvider.createSender(OkHttpGrpcSenderProvider.java:45)
	at io.opentelemetry.exporter.internal.grpc.GrpcExporterBuilder.build(GrpcExporterBuilder.java:201)
	at io.opentelemetry.exporter.otlp.trace.OtlpGrpcSpanExporterBuilder.build(OtlpGrpcSpanExporterBuilder.java:264)
	at io.opentelemetry.exporter.otlp.internal.OtlpSpanExporterProvider.createExporter(OtlpSpanExporterProvider.java:74)
	at io.opentelemetry.sdk.autoconfigure.internal.SpiHelper.lambda$loadConfigurable$0(SpiHelper.java:85)
	at io.opentelemetry.sdk.autoconfigure.internal.NamedSpiManager.tryLoadImplementationForName(NamedSpiManager.java:51)
	at java.base/java.util.concurrent.ConcurrentHashMap.computeIfAbsent(ConcurrentHashMap.java:1708)
	at io.opentelemetry.sdk.autoconfigure.internal.NamedSpiManager.getByName(NamedSpiManager.java:41)
	at io.opentelemetry.sdk.autoconfigure.SpanExporterConfiguration.configureExporter(SpanExporterConfiguration.java:92)
	at io.opentelemetry.sdk.autoconfigure.SpanExporterConfiguration.configureSpanExporters(SpanExporterConfiguration.java:68)
	at io.opentelemetry.sdk.autoconfigure.TracerProviderConfiguration.configureTracerProvider(TracerProviderConfiguration.java:58)
	at io.opentelemetry.sdk.autoconfigure.AutoConfiguredOpenTelemetrySdkBuilder.build(AutoConfiguredOpenTelemetrySdkBuilder.java:467)
	at io.quarkus.opentelemetry.runtime.OpenTelemetryRecorder$2.apply(OpenTelemetryRecorder.java:115)
	at io.quarkus.opentelemetry.runtime.OpenTelemetryRecorder$2.apply(OpenTelemetryRecorder.java:88)
	at io.opentelemetry.api.OpenTelemetry_Le6zQbzkojAYO_OiKIQWJf4lGa4_Synthetic_Bean.createSynthetic(Unknown Source)
	at io.opentelemetry.api.OpenTelemetry_Le6zQbzkojAYO_OiKIQWJf4lGa4_Synthetic_Bean.doCreate(Unknown Source)
	at io.opentelemetry.api.OpenTelemetry_Le6zQbzkojAYO_OiKIQWJf4lGa4_Synthetic_Bean.create(Unknown Source)
	at io.opentelemetry.api.OpenTelemetry_Le6zQbzkojAYO_OiKIQWJf4lGa4_Synthetic_Bean.create(Unknown Source)
	at io.quarkus.arc.impl.AbstractSharedContext.createInstanceHandle(AbstractSharedContext.java:119)
	at io.quarkus.arc.impl.AbstractSharedContext$1.get(AbstractSharedContext.java:38)
	at io.quarkus.arc.impl.AbstractSharedContext$1.get(AbstractSharedContext.java:35)
	at io.quarkus.arc.impl.LazyValue.get(LazyValue.java:32)
	at io.quarkus.arc.impl.ComputingCache.computeIfAbsent(ComputingCache.java:69)
	at io.quarkus.arc.impl.ComputingCacheContextInstances.computeIfAbsent(ComputingCacheContextInstances.java:19)
	at io.quarkus.arc.impl.AbstractSharedContext.get(AbstractSharedContext.java:35)
	at io.opentelemetry.api.OpenTelemetry_Le6zQbzkojAYO_OiKIQWJf4lGa4_Synthetic_Bean.get(Unknown Source)
	at io.opentelemetry.api.OpenTelemetry_Le6zQbzkojAYO_OiKIQWJf4lGa4_Synthetic_Bean.get(Unknown Source)
	at io.quarkus.arc.impl.InstanceImpl.getBeanInstance(InstanceImpl.java:325)
	at io.quarkus.arc.impl.InstanceImpl.getInternal(InstanceImpl.java:309)
	at io.quarkus.arc.impl.InstanceImpl.get(InstanceImpl.java:190)
	at io.quarkus.arc.runtime.BeanContainerImpl.beanInstance(BeanContainerImpl.java:28)
	at io.quarkus.opentelemetry.runtime.tracing.intrumentation.InstrumentationRecorder.setupVertxTracer(InstrumentationRecorder.java:59)
	at io.quarkus.runner.recorded.OpenTelemetryProcessor$setupVertx1012958309.deploy_0(Unknown Source)
	at io.quarkus.runner.recorded.OpenTelemetryProcessor$setupVertx1012958309.deploy(Unknown Source)
	... 11 more
Caused by: java.lang.ClassNotFoundException: okhttp3.Callback
	at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641)
	at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188)
	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:526)
	at io.quarkus.bootstrap.classloading.QuarkusClassLoader.loadClass(QuarkusClassLoader.java:576)
	at io.quarkus.bootstrap.classloading.QuarkusClassLoader.loadClass(QuarkusClassLoader.java:523)
	... 45 more

Expected behavior

Quarkus should start up normally when setting the exporter to otlp

Actual behavior

Quarkus throws an exception during startup

How to Reproduce?

1. Create a fresh Quarkus app with the opentelemetry extension
2. Set quarkus.otel.traces.exporter=otlp in application.properties

Output of uname -a or ver

Ubuntu 25.04

Output of java -version

OpenJDK 21.0.7

Quarkus version or git rev

3.23.4

Build tool (ie. output of mvnw --version or gradlew --version)

Gradle 8.14.2

Additional information

I was following the guide for connecting Quarkus to SigNoz, which recommends using the otlp exporter: https://signoz.io/docs/instrumentation/opentelemetry-quarkus/

[quarkus-bot]

/cc @brunobat (opentelemetry), @radcortez (opentelemetry)

[geoand]

@brunobat was that value ever meant to work?

[LarsSven]

It is mentioned in the SigNoz documentation so I hope that it at least worked at the time that they wrote their guide? https://signoz.io/docs/instrumentation/opentelemetry-quarkus/

If I look at their dependency versions it seems to be sometime around Quarkus 3.17 that they wrote this.

[brunobat]

There was a plan to support otlp but we haven't implemented it yet because it hasn't been need.
I need to write a better documentation around this. otlp in not needed with Quarkus. Our default exporters are already otlp.

[brunobat]

... Writing right now.

[brunobat]

Please check: #48580

[LarsSven]

If otlp as an exporter does not work and cdi works in all cases anyways, why not just remove otlp?

[geoand]

@LarsSven exactly