OpenTelemetry custom SpanProcessor support

[amoscatelli]

Hi guys !
Are OpenTelemetry SpanProcessor 's supported by current quarkus integration ?
When I run locally everything works when using extra/custom SpanProcessor, when I compile in native mode and deploy on kubernetes I see the SpanProcessor is correctly called, I see no error but no spans are exported.

import io.opentelemetry.context.Context;
import io.opentelemetry.sdk.trace.ReadWriteSpan;
import io.opentelemetry.sdk.trace.ReadableSpan;
import io.opentelemetry.sdk.trace.SpanProcessor;
import jakarta.enterprise.context.ApplicationScoped;

@ApplicationScoped
public class EndUserSpanProcessor implements SpanProcessor {

    @Override
    public void onStart(Context parentContext, ReadWriteSpan span) {
        System.out.println("HELLO!");
    }

    @Override
    public boolean isStartRequired() {
        return Boolean.TRUE;
    }

    @Override
    public void onEnd(ReadableSpan span) {
    }

    @Override
    public boolean isEndRequired() {
        return Boolean.TRUE;
    }

}

I also tried with this official example :
https://github.com/open-telemetry/opentelemetry-java-instrumentation/blob/main/examples/extension/src/main/java/com/example/javaagent/DemoSpanProcessor.java

Thanks in advance

[quarkus-bot[bot]]

/cc @Sgitario (kubernetes), @brunobat (opentelemetry), @geoand (kubernetes), @iocanel (kubernetes), @radcortez (opentelemetry)

[amoscatelli]

Of course if I remove the span processor, everything works again :)

[brunobat]

You need a span exporter, not just the processor.
There are 2 ways to do this in Quarkus. Using CDI or the OTel side SPI.

Using the SPI, you can take advantage of the Quarkus bundled SpanExporterCDIProvider, like in this integration test:

quarkus/integration-tests/opentelemetry-spi/src/main/resources/META-INF/services/io.opentelemetry.sdk.autoconfigure.spi.traces.ConfigurableSpanExporterProvider

Line 1 in 3e6b2a5

io.quarkus.opentelemetry.runtime.tracing.spi.SpanExporterCDIProvider

With the default CDI exporter, you can override the LateBoundBatchSpanProcessor

quarkus/extensions/opentelemetry/runtime/src/main/java/io/quarkus/opentelemetry/runtime/exporter/otlp/OtlpRecorder.java

Line 64 in 3e6b2a5

LateBoundBatchSpanProcessor delayedProcessor = CDI.current()

[amoscatelli]

@brunobat thank you for your answer.
Yet, I can't unrestand why I need an exporter.

I just want to modify the spans before they are exported. An Exporter would override how the spans are exported ...
According to OpenTelemetry documentation I don't need nothing more of a SpanProcessor, also this is actually working when using quarkus:dev.

Also, I would like to use the OpenTelemetry api only (and not using quarkus specific solutions).

Am I missing something ?

[amoscatelli]

Yea that was my intention to, I am happy you consider this handy.
To tell the truth opentelemetry java agent already does this automatically for other runtimes (for example Wildfly/Undertow).
So yes, I think this should be brought to the main extension too.

[amoscatelli]

I created the issue

[brunobat]

Thanks for #33407

[amoscatelli]

@brunobat the issue is solved, so maybe we could do as you said (add the functionality to the main extension)

[brunobat]

Sure. Can you please open an issue with the details of the behaviour you want?
We can then discuss there all the details.