io.opns.otl.kafka

Class TracingConsumerInterceptor<K,V>

java.lang.Object

io.opns.otl.kafka.TracingConsumerInterceptor<K,V>

All Implemented Interfaces:

AutoCloseable, org.apache.kafka.clients.consumer.ConsumerInterceptor<K,V>, org.apache.kafka.common.Configurable

public class TracingConsumerInterceptor<K,V>
extends Object
implements org.apache.kafka.clients.consumer.ConsumerInterceptor<K,V>

The interceptor class for kafka consumer.

A plugin interface that allows you to intercept the records received by the consumer. Span propagation over message bus is always async, where the sender/producer takes the responsibility of creating a new span and passes on the context data, which will eventually be acknowledged by the consumer, as it creates a follows_from span and finished it immediately. Thus the two spans in question represents the amount of time a kafka message actually waited in the queue until before it's consumption.

This is how you can use the interceptor.

 
     .....
     public Consumer createConsumer() {
         Consumer<String, byte[]> consumer;
         
         Properties config = new Properties();
         
         config.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:9092");
         config.put(ConsumerConfig.CLIENT_ID_CONFIG, "Consumer-1");
         ....
         ....
         config.put(ConsumerConfig.INTERCEPTOR_CLASSES_CONFIG
                 , "io.opns.otl.kafka.TracingConsumerInterceptor");
 
         consumer = new KafkaConsumer<String, byte[]>(config);
         return consumer
     }
 
     public void receive(String topic) {
         Consumer<String, byte[]> consumer = createConsumer();
         consumer.subscribe(Collections.singletonList(topic));
 
         while (true) {
             ConsumerRecords<String, byte[]> records = consumer.poll(Duration.ofMillis(1000L));
             if (!records.isEmpty()) {
                  for (ConsumerRecord<String, byte[]> record : records) {
                      // process the individual message
                  }
             }
             consumer.commitSync();
         }
         // consumer.close();
     }
 
 

Note that the interceptor will not create any new span. It will acknowledge the span present in individual message, and alose it accordingly, just before consuming the same, thus marking the end of that span. The application code (followup from consumer) may choose to create a new span to represent it's own work.

Author:

Sudiptasish Chanda

Constructor Summary

Constructors

Constructor and Description
TracingConsumerInterceptor()

Method Summary

Modifier and Type	Method and Description
void	close()
void	configure(Map<String,?> map)
void	onCommit(Map<org.apache.kafka.common.TopicPartition,org.apache.kafka.clients.consumer.OffsetAndMetadata> map)
org.apache.kafka.clients.consumer.ConsumerRecords<K,V>	onConsume(org.apache.kafka.clients.consumer.ConsumerRecords<K,V> records)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TracingConsumerInterceptor

public TracingConsumerInterceptor()

Method Detail

configure

public void configure(Map<String,?> map)

Specified by:

configure in interface org.apache.kafka.common.Configurable

onConsume

public org.apache.kafka.clients.consumer.ConsumerRecords<K,V> onConsume(org.apache.kafka.clients.consumer.ConsumerRecords<K,V> records)

Specified by:

onConsume in interface org.apache.kafka.clients.consumer.ConsumerInterceptor<K,V>

onCommit

public void onCommit(Map<org.apache.kafka.common.TopicPartition,org.apache.kafka.clients.consumer.OffsetAndMetadata> map)

Specified by:

onCommit in interface org.apache.kafka.clients.consumer.ConsumerInterceptor<K,V>

close

public void close()

Specified by:

close in interface AutoCloseable

Specified by:

close in interface org.apache.kafka.clients.consumer.ConsumerInterceptor<K,V>