22.3. Setting up distributed tracing
Enable distributed tracing in Kafka components by specifying a tracing type in the custom resource. Instrument tracers in Kafka clients for end-to-end tracking of messages.
To set up distributed tracing, follow these procedures in order:
- Enable tracing for MirrorMaker, Kafka Connect, and the Kafka Bridge
Set up tracing for clients:
Instrument clients with tracers:
22.3.1. Prerequisites 复制链接链接已复制到粘贴板!
Before setting up distributed tracing, make sure Jaeger backend components are deployed to your OpenShift cluster. We recommend using the Jaeger operator for deploying Jaeger on your OpenShift cluster.
For deployment instructions, see the Jaeger documentation.
Setting up tracing for applications and systems beyond Streams for Apache Kafka is outside the scope of this content.
Distributed tracing is supported for MirrorMaker, MirrorMaker 2, Kafka Connect, and the Streams for Apache Kafka Bridge. Configure the custom resource of the component to specify and enable a tracer service.
Enabling tracing in a resource triggers the following events:
- Interceptor classes are updated in the integrated consumers and producers of the component.
- For MirrorMaker, MirrorMaker 2, and Kafka Connect, the tracing agent initializes a tracer based on the tracing configuration defined in the resource.
- For the Kafka Bridge, a tracer based on the tracing configuration defined in the resource is initialized by the Kafka Bridge itself.
You can enable tracing that uses OpenTelemetry.
Tracing in MirrorMaker and MirrorMaker 2
For MirrorMaker and MirrorMaker 2, messages are traced from the source cluster to the target cluster. The trace data records messages entering and leaving the MirrorMaker or MirrorMaker 2 component.
Tracing in Kafka Connect
For Kafka Connect, only messages produced and consumed by Kafka Connect are traced. To trace messages sent between Kafka Connect and external systems, you must configure tracing in the connectors for those systems.
Tracing in the Kafka Bridge
For the Kafka Bridge, messages produced and consumed by the Kafka Bridge are traced. Incoming HTTP requests from client applications to send and receive messages through the Kafka Bridge are also traced. To have end-to-end tracing, you must configure tracing in your HTTP clients.
Procedure
Perform these steps for each KafkaMirrorMaker, KafkaMirrorMaker2, KafkaConnect, and KafkaBridge resource.
In the
spec.templateproperty, configure the tracer service.- Use the tracing environment variables as template configuration properties.
-
For OpenTelemetry, set the
spec.tracing.typeproperty toopentelemetry.
Example tracing configuration for Kafka Connect using OpenTelemetry
apiVersion: kafka.strimzi.io/v1beta2 kind: KafkaConnect metadata: name: my-connect-cluster spec: #... template: connectContainer: env: - name: OTEL_SERVICE_NAME value: my-otel-service - name: OTEL_EXPORTER_OTLP_ENDPOINT value: "http://otlp-host:4317" tracing: type: opentelemetry #...Example tracing configuration for MirrorMaker using OpenTelemetry
apiVersion: kafka.strimzi.io/v1beta2 kind: KafkaMirrorMaker metadata: name: my-mirror-maker spec: #... template: mirrorMakerContainer: env: - name: OTEL_SERVICE_NAME value: my-otel-service - name: OTEL_EXPORTER_OTLP_ENDPOINT value: "http://otlp-host:4317" tracing: type: opentelemetry #...Example tracing configuration for MirrorMaker 2 using OpenTelemetry
apiVersion: kafka.strimzi.io/v1beta2 kind: KafkaMirrorMaker2 metadata: name: my-mm2-cluster spec: #... template: connectContainer: env: - name: OTEL_SERVICE_NAME value: my-otel-service - name: OTEL_EXPORTER_OTLP_ENDPOINT value: "http://otlp-host:4317" tracing: type: opentelemetry #...Example tracing configuration for the Kafka Bridge using OpenTelemetry
apiVersion: kafka.strimzi.io/v1beta2 kind: KafkaBridge metadata: name: my-bridge spec: #... template: bridgeContainer: env: - name: OTEL_SERVICE_NAME value: my-otel-service - name: OTEL_EXPORTER_OTLP_ENDPOINT value: "http://otlp-host:4317" tracing: type: opentelemetry #...Create or update the resource:
oc apply -f <resource_configuration_file>
22.3.3. Initializing tracing for Kafka clients 复制链接链接已复制到粘贴板!
Initialize a tracer for OpenTelemetry, then instrument your client applications for distributed tracing. You can instrument Kafka producer and consumer clients, and Kafka Streams API applications.
Configure and initialize a tracer using a set of tracing environment variables.
Procedure
In each client application add the dependencies for the tracer:
Add the Maven dependencies to the
pom.xmlfile for the client application:Dependencies for OpenTelemetry
<dependency> <groupId>io.opentelemetry.semconv</groupId> <artifactId>opentelemetry-semconv</artifactId> <version>1.21.0-alpha</version> </dependency> <dependency> <groupId>io.opentelemetry</groupId> <artifactId>opentelemetry-exporter-otlp</artifactId> <version>1.34.1</version> <exclusions> <exclusion> <groupId>io.opentelemetry</groupId> <artifactId>opentelemetry-exporter-sender-okhttp</artifactId> </exclusion> </exclusions> </dependency> <dependency> <groupId>io.opentelemetry</groupId> <artifactId>opentelemetry-exporter-sender-grpc-managed-channel</artifactId> <version>1.34.1</version> <scope>runtime</scope> </dependency> <dependency> <groupId>io.opentelemetry</groupId> <artifactId>opentelemetry-sdk-extension-autoconfigure</artifactId> <version>1.34.1</version> </dependency> <dependency> <groupId>io.opentelemetry.instrumentation</groupId> <artifactId>opentelemetry-kafka-clients-2.6</artifactId> <version>1.32.0-alpha</version> </dependency> <dependency> <groupId>io.opentelemetry</groupId> <artifactId>opentelemetry-sdk</artifactId> <version>1.34.1</version> </dependency> <dependency> <groupId>io.opentelemetry</groupId> <artifactId>opentelemetry-exporter-sender-jdk</artifactId> <version>1.34.1-alpha</version> <scope>runtime</scope> </dependency> <dependency> <groupId>io.grpc</groupId> <artifactId>grpc-netty-shaded</artifactId> <version>1.61.0</version> </dependency>- Define the configuration of the tracer using the tracing environment variables.
Create a tracer, which is initialized with the environment variables:
Creating a tracer for OpenTelemetry
OpenTelemetry ot = GlobalOpenTelemetry.get();Register the tracer as a global tracer:
GlobalTracer.register(tracer);Instrument your client:
Instrument application code to enable tracing in Kafka producers and consumers. Use a decorator pattern or interceptors to instrument your Java producer and consumer application code for tracing. You can then record traces when messages are produced or retrieved from a topic.
OpenTelemetry instrumentation project provides classes that support instrumentation of producers and consumers.
- Decorator instrumentation
- For decorator instrumentation, create a modified producer or consumer instance for tracing.
- Interceptor instrumentation
- For interceptor instrumentation, add the tracing capability to the consumer or producer configuration.
Prerequisites
You have initialized tracing for the client.
You enable instrumentation in producer and consumer applications by adding the tracing JARs as dependencies to your project.
Procedure
Perform these steps in the application code of each producer and consumer application. Instrument your client application code using either a decorator pattern or interceptors.
To use a decorator pattern, create a modified producer or consumer instance to send or receive messages.
You pass the original
KafkaProducerorKafkaConsumerclass.Example decorator instrumentation for OpenTelemetry
// Producer instance Producer < String, String > op = new KafkaProducer < > ( configs, new StringSerializer(), new StringSerializer() ); Producer < String, String > producer = tracing.wrap(op); KafkaTracing tracing = KafkaTracing.create(GlobalOpenTelemetry.get()); producer.send(...); //consumer instance Consumer<String, String> oc = new KafkaConsumer<>( configs, new StringDeserializer(), new StringDeserializer() ); Consumer<String, String> consumer = tracing.wrap(oc); consumer.subscribe(Collections.singleton("mytopic")); ConsumerRecords<Integer, String> records = consumer.poll(1000); ConsumerRecord<Integer, String> record = ... SpanContext spanContext = TracingKafkaUtils.extractSpanContext(record.headers(), tracer);To use interceptors, set the interceptor class in the producer or consumer configuration.
You use the
KafkaProducerandKafkaConsumerclasses in the usual way. TheTracingProducerInterceptorandTracingConsumerInterceptorinterceptor classes take care of the tracing capability.Example producer configuration using interceptors
senderProps.put(ProducerConfig.INTERCEPTOR_CLASSES_CONFIG, TracingProducerInterceptor.class.getName()); KafkaProducer<Integer, String> producer = new KafkaProducer<>(senderProps); producer.send(...);Example consumer configuration using interceptors
consumerProps.put(ConsumerConfig.INTERCEPTOR_CLASSES_CONFIG, TracingConsumerInterceptor.class.getName()); KafkaConsumer<Integer, String> consumer = new KafkaConsumer<>(consumerProps); consumer.subscribe(Collections.singletonList("messages")); ConsumerRecords<Integer, String> records = consumer.poll(1000); ConsumerRecord<Integer, String> record = ... SpanContext spanContext = TracingKafkaUtils.extractSpanContext(record.headers(), tracer);
Instrument application code to enable tracing in Kafka Streams API applications. Use a decorator pattern or interceptors to instrument your Kafka Streams API applications for tracing. You can then record traces when messages are produced or retrieved from a topic.
- Decorator instrumentation
-
For decorator instrumentation, create a modified Kafka Streams instance for tracing. For OpenTelemetry, you need to create a custom
TracingKafkaClientSupplierclass to provide tracing instrumentation for Kafka Streams. - Interceptor instrumentation
- For interceptor instrumentation, add the tracing capability to the Kafka Streams producer and consumer configuration.
Prerequisites
You have initialized tracing for the client.
You enable instrumentation in Kafka Streams applications by adding the tracing JARs as dependencies to your project.
-
To instrument Kafka Streams with OpenTelemetry, you’ll need to write a custom
TracingKafkaClientSupplier. The custom
TracingKafkaClientSuppliercan extend Kafka’sDefaultKafkaClientSupplier, overriding the producer and consumer creation methods to wrap the instances with the telemetry-related code.Example custom
TracingKafkaClientSupplierprivate class TracingKafkaClientSupplier extends DefaultKafkaClientSupplier { @Override public Producer<byte[], byte[]> getProducer(Map<String, Object> config) { KafkaTelemetry telemetry = KafkaTelemetry.create(GlobalOpenTelemetry.get()); return telemetry.wrap(super.getProducer(config)); } @Override public Consumer<byte[], byte[]> getConsumer(Map<String, Object> config) { KafkaTelemetry telemetry = KafkaTelemetry.create(GlobalOpenTelemetry.get()); return telemetry.wrap(super.getConsumer(config)); } @Override public Consumer<byte[], byte[]> getRestoreConsumer(Map<String, Object> config) { return this.getConsumer(config); } @Override public Consumer<byte[], byte[]> getGlobalConsumer(Map<String, Object> config) { return this.getConsumer(config); } }
Procedure
Perform these steps for each Kafka Streams API application.
To use a decorator pattern, create an instance of the
TracingKafkaClientSuppliersupplier interface, then provide the supplier interface toKafkaStreams.Example decorator instrumentation
KafkaClientSupplier supplier = new TracingKafkaClientSupplier(tracer); KafkaStreams streams = new KafkaStreams(builder.build(), new StreamsConfig(config), supplier); streams.start();To use interceptors, set the interceptor class in the Kafka Streams producer and consumer configuration.
The
TracingProducerInterceptorandTracingConsumerInterceptorinterceptor classes take care of the tracing capability.Example producer and consumer configuration using interceptors
props.put(StreamsConfig.PRODUCER_PREFIX + ProducerConfig.INTERCEPTOR_CLASSES_CONFIG, TracingProducerInterceptor.class.getName()); props.put(StreamsConfig.CONSUMER_PREFIX + ConsumerConfig.INTERCEPTOR_CLASSES_CONFIG, TracingConsumerInterceptor.class.getName());
Instead of the default OTLP system, you can specify other tracing systems that are supported by OpenTelemetry. You do this by adding the required artifacts to the Kafka image provided with Streams for Apache Kafka. Any required implementation specific environment variables must also be set. You then enable the new tracing implementation using the OTEL_TRACES_EXPORTER environment variable.
This procedure shows how to implement Zipkin tracing.
Procedure
Add the tracing artifacts to the
/opt/kafka/libs/directory of the Streams for Apache Kafka image.You can use the Kafka container image on the Red Hat Ecosystem Catalog as a base image for creating a new custom image.
OpenTelemetry artifact for Zipkin
io.opentelemetry:opentelemetry-exporter-zipkinSet the tracing exporter and endpoint for the new tracing implementation.
Example Zikpin tracer configuration
apiVersion: kafka.strimzi.io/v1beta2 kind: KafkaMirrorMaker2 metadata: name: my-mm2-cluster spec: #... template: connectContainer: env: - name: OTEL_SERVICE_NAME value: my-zipkin-service - name: OTEL_EXPORTER_ZIPKIN_ENDPOINT value: http://zipkin-exporter-host-name:9411/api/v2/spans1 - name: OTEL_TRACES_EXPORTER value: zipkin2 tracing: type: opentelemetry #...
22.3.7. Specifying custom span names for OpenTelemetry 复制链接链接已复制到粘贴板!
A tracing span is a logical unit of work in Jaeger, with an operation name, start time, and duration. Spans have built-in names, but you can specify custom span names in your Kafka client instrumentation where used.
Specifying custom span names is optional and only applies when using a decorator pattern in producer and consumer client instrumentation or Kafka Streams instrumentation.
Custom span names cannot be specified directly with OpenTelemetry. Instead, you retrieve span names by adding code to your client application to extract additional tags and attributes.
Example code to extract attributes
//Defines attribute extraction for a producer
private static class ProducerAttribExtractor implements AttributesExtractor < ProducerRecord < ? , ? > , Void > {
@Override
public void onStart(AttributesBuilder attributes, ProducerRecord < ? , ? > producerRecord) {
set(attributes, AttributeKey.stringKey("prod_start"), "prod1");
}
@Override
public void onEnd(AttributesBuilder attributes, ProducerRecord < ? , ? > producerRecord, @Nullable Void unused, @Nullable Throwable error) {
set(attributes, AttributeKey.stringKey("prod_end"), "prod2");
}
}
//Defines attribute extraction for a consumer
private static class ConsumerAttribExtractor implements AttributesExtractor < ConsumerRecord < ? , ? > , Void > {
@Override
public void onStart(AttributesBuilder attributes, ConsumerRecord < ? , ? > producerRecord) {
set(attributes, AttributeKey.stringKey("con_start"), "con1");
}
@Override
public void onEnd(AttributesBuilder attributes, ConsumerRecord < ? , ? > producerRecord, @Nullable Void unused, @Nullable Throwable error) {
set(attributes, AttributeKey.stringKey("con_end"), "con2");
}
}
//Extracts the attributes
public static void main(String[] args) throws Exception {
Map < String, Object > configs = new HashMap < > (Collections.singletonMap(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:9092"));
System.setProperty("otel.traces.exporter", "jaeger");
System.setProperty("otel.service.name", "myapp1");
KafkaTracing tracing = KafkaTracing.newBuilder(GlobalOpenTelemetry.get())
.addProducerAttributesExtractors(new ProducerAttribExtractor())
.addConsumerAttributesExtractors(new ConsumerAttribExtractor())
.build();