Skip to content

feat(kafka-clients): handle readonly record headers on context injection through producer wrapper #17530

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wpessers wants to merge 2 commits into
base: main
Choose a base branch
from
Open

feat(kafka-clients): handle readonly record headers on context injection through producer wrapper #17530

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
1ca9589
feat(kafka-clients): handle readonly record headers on context inject…
wpessers Apr 4, 2026
eb17d42
refactor: reuse existing retry logic from KafkaPropagation.java
wpessers Apr 7, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
31 changes: 11 additions & 20 deletions ...a/io/opentelemetry/instrumentation/kafkaclients/v2_6/internal/KafkaProducerTelemetry.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -5,23 +5,18 @@

package io.opentelemetry.instrumentation.kafkaclients.v2_6.internal;

import static java.util.logging.Level.WARNING;

import io.opentelemetry.context.Context;
import io.opentelemetry.context.Scope;
import io.opentelemetry.context.propagation.TextMapPropagator;
import io.opentelemetry.context.propagation.TextMapSetter;
import io.opentelemetry.instrumentation.api.instrumenter.Instrumenter;
import io.opentelemetry.instrumentation.kafkaclients.common.v0_11.internal.KafkaHeadersSetter;
import io.opentelemetry.instrumentation.kafkaclients.common.v0_11.internal.KafkaProducerRequest;
import io.opentelemetry.instrumentation.kafkaclients.common.v0_11.internal.KafkaPropagation;
import java.util.concurrent.Future;
import java.util.function.BiFunction;
import java.util.logging.Logger;
import org.apache.kafka.clients.producer.Callback;
import org.apache.kafka.clients.producer.Producer;
import org.apache.kafka.clients.producer.ProducerRecord;
import org.apache.kafka.clients.producer.RecordMetadata;
import org.apache.kafka.common.header.Headers;

/**
* Helper for producer-side instrumentation.
Expand All @@ -30,10 +25,6 @@
* at any time.
*/
public class KafkaProducerTelemetry {
private static final Logger logger = Logger.getLogger(KafkaProducerTelemetry.class.getName());

private static final TextMapSetter<Headers> SETTER = KafkaHeadersSetter.INSTANCE;

private final TextMapPropagator propagator;
private final Instrumenter<KafkaProducerRequest, RecordMetadata> producerInstrumenter;
private final boolean producerPropagationEnabled;
Expand All @@ -52,24 +43,24 @@ public KafkaProducerTelemetry(
*
* @param record the producer record to inject span info.
*/
public <K, V> void buildAndInjectSpan(ProducerRecord<K, V> record, String clientId) {
public <K, V> ProducerRecord<K, V> buildAndInjectSpan(
ProducerRecord<K, V> record, String clientId) {
Context parentContext = Context.current();

KafkaProducerRequest request = KafkaProducerRequest.create(record, clientId);
if (!producerInstrumenter.shouldStart(parentContext, request)) {
return;
return record;
}

Context context = producerInstrumenter.start(parentContext, request);
if (producerPropagationEnabled) {
try {
propagator.inject(context, record.headers(), SETTER);
} catch (Throwable t) {
// it can happen if headers are read only (when record is sent second time)
logger.log(WARNING, "failed to inject span context. sending record second time?", t);
try {
if (producerPropagationEnabled) {
record = KafkaPropagation.propagateContext(propagator, context, record);
}
} finally {
producerInstrumenter.end(context, request, null, null);
}
producerInstrumenter.end(context, request, null, null);
return record;
}

/**
Expand All @@ -93,7 +84,7 @@ public <K, V> Future<RecordMetadata> buildAndInjectSpan(

Context context = producerInstrumenter.start(parentContext, request);
if (producerPropagationEnabled) {
propagator.inject(context, record.headers(), SETTER);
record = KafkaPropagation.propagateContext(propagator, context, record);
}

try (Scope ignored = context.makeCurrent()) {
Expand Down
2 changes: 1 addition & 1 deletion ...elemetry/instrumentation/kafkaclients/v2_6/internal/OpenTelemetryProducerInterceptor.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -32,7 +32,7 @@ public class OpenTelemetryProducerInterceptor<K, V> implements ProducerIntercept
@CanIgnoreReturnValue
public ProducerRecord<K, V> onSend(ProducerRecord<K, V> producerRecord) {
if (producerTelemetry != null) {
producerTelemetry.buildAndInjectSpan(producerRecord, clientId);
return producerTelemetry.buildAndInjectSpan(producerRecord, clientId);
}
return producerRecord;
}
Expand Down
29 changes: 29 additions & 0 deletions ...c/test/java/io/opentelemetry/instrumentation/kafkaclients/v2_6/ExceptionHandlingTest.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -5,14 +5,18 @@

package io.opentelemetry.instrumentation.kafkaclients.v2_6;

import static org.assertj.core.api.Assertions.assertThatNoException;
import static org.assertj.core.api.Assertions.assertThatThrownBy;

import io.opentelemetry.instrumentation.testing.junit.InstrumentationExtension;
import io.opentelemetry.instrumentation.testing.junit.LibraryInstrumentationExtension;
import java.lang.reflect.Proxy;
import java.time.Duration;
import java.util.concurrent.CompletableFuture;
import org.apache.kafka.clients.consumer.Consumer;
import org.apache.kafka.clients.producer.Producer;
import org.apache.kafka.clients.producer.ProducerRecord;
import org.apache.kafka.common.header.internals.RecordHeaders;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.RegisterExtension;

Expand Down Expand Up @@ -57,4 +61,29 @@ void testProducerExceptionPropagatesToCaller() {
.isInstanceOf(IllegalStateException.class)
.hasMessage("can't invoke");
}

@Test
@SuppressWarnings({"unchecked"})
void testProducerHandlesReadOnlyHeaders() {
Producer<String, String> producer =
Copy link
Copy Markdown
Contributor

@laurit laurit Apr 6, 2026

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

alternatively could use a mock, but this is fine too

Copy link
Copy Markdown
Member Author

@wpessers wpessers Apr 7, 2026

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I guess it may be more readable with a mock, I just went with this approach because it mirrors the setup of the existing tests in this same file. Your call though, I'd happily change it to use a mock if preferred!

(Producer<String, String>)
Proxy.newProxyInstance(
ExceptionHandlingTest.class.getClassLoader(),
new Class<?>[] {Producer.class},
(proxy, method, args) -> {
if ("send".equals(method.getName())) {
return CompletableFuture.completedFuture(null);
}
throw new IllegalStateException("can't invoke");
});
KafkaTelemetry telemetry = KafkaTelemetry.builder(testing.getOpenTelemetry()).build();
Producer<String, String> wrappedProducer = telemetry.wrap(producer);

ProducerRecord<String, String> record =
new ProducerRecord<>(
"test-topic", null, null, "test-key", "test-value", new RecordHeaders());
((RecordHeaders) record.headers()).setReadOnly();
assertThatNoException()
.isThrownBy(() -> testing.runWithSpan("parent", () -> wrappedProducer.send(record)));
}
}
18 changes: 12 additions & 6 deletions ...io/opentelemetry/instrumentation/kafkaclients/common/v0_11/internal/KafkaPropagation.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -7,6 +7,7 @@

import io.opentelemetry.api.GlobalOpenTelemetry;
import io.opentelemetry.context.Context;
import io.opentelemetry.context.propagation.TextMapPropagator;
import io.opentelemetry.javaagent.tooling.muzzle.NoMuzzle;
import org.apache.kafka.clients.ApiVersions;
import org.apache.kafka.clients.producer.ProducerRecord;
Expand Down Expand Up @@ -50,8 +51,14 @@ private static boolean hasMaxUsableProduceMagic() {

public static <K, V> ProducerRecord<K, V> propagateContext(
Context context, ProducerRecord<K, V> record) {
return propagateContext(
GlobalOpenTelemetry.getPropagators().getTextMapPropagator(), context, record);
}

public static <K, V> ProducerRecord<K, V> propagateContext(
TextMapPropagator propagator, Context context, ProducerRecord<K, V> record) {
try {
inject(context, record);
inject(propagator, context, record);
} catch (IllegalStateException e) {
// headers must be read-only from reused record. try again with new one.
record =
Expand All @@ -63,15 +70,14 @@ record =
record.value(),
record.headers());

inject(context, record);
inject(propagator, context, record);
}
return record;
}

private static <K, V> void inject(Context context, ProducerRecord<K, V> record) {
GlobalOpenTelemetry.getPropagators()
.getTextMapPropagator()
.inject(context, record.headers(), SETTER);
private static <K, V> void inject(
TextMapPropagator propagator, Context context, ProducerRecord<K, V> record) {
propagator.inject(context, record.headers(), SETTER);
}

private KafkaPropagation() {}
Expand Down
Loading