title: Kafka uncaught exception
body: <p>I am getting the following exception while the producer is publishing the first message, I am trying to understand what the error means</p>
  <pre><code>Uncaught exception in thread 'kafka-producer-network-thread | producer-1':
  
  java.lang.AbstractMethodError: Method brave/kafka/clients/TracingProducer.close(Ljava/time/Duration;)V is abstract
      at brave.kafka.clients.TracingProducer.close(TracingProducer.java) ~[brave-instrumentation-kafka-clients-5.6.1.jar:na]
      at org.springframework.kafka.core.KafkaTemplate.closeProducer(KafkaTemplate.java:382) ~[spring-kafka-2.3.6.RELEASE.jar:2.3.6.RELEASE]
      at org.springframework.kafka.core.KafkaTemplate.lambda$buildCallback$4(KafkaTemplate.java:433) ~[spring-kafka-2.3.6.RELEASE.jar:2.3.6.RELEASE]
      at org.apache.kafka.clients.producer.KafkaProducer$InterceptorCallback.onCompletion(KafkaProducer.java:1318) ~[kafka-clients-2.3.1.jar:na]
      at org.apache.kafka.clients.producer.internals.ProducerBatch.completeFutureAndFireCallbacks(ProducerBatch.java:227) ~[kafka-clients-2.3.1.jar:na]
      at org.apache.kafka.clients.producer.internals.ProducerBatch.done(ProducerBatch.java:196) ~[kafka-clients-2.3.1.jar:na]
      at org.apache.kafka.clients.producer.internals.Sender.completeBatch(Sender.java:707) ~[kafka-clients-2.3.1.jar:na]
      at org.apache.kafka.clients.producer.internals.Sender.completeBatch(Sender.java:688) ~[kafka-clients-2.3.1.jar:na]
      at org.apache.kafka.clients.producer.internals.Sender.handleProduceResponse(Sender.java:596) ~[kafka-clients-2.3.1.jar:na]
      at org.apache.kafka.clients.producer.internals.Sender.access$100(Sender.java:74) ~[kafka-clients-2.3.1.jar:na]
      at org.apache.kafka.clients.producer.internals.Sender$1.onComplete(Sender.java:798) ~[kafka-clients-2.3.1.jar:na]
      at org.apache.kafka.clients.ClientResponse.onComplete(ClientResponse.java:109) ~[kafka-clients-2.3.1.jar:na]
      at org.apache.kafka.clients.NetworkClient.completeResponses(NetworkClient.java:561) ~[kafka-clients-2.3.1.jar:na]
      at org.apache.kafka.clients.NetworkClient.poll(NetworkClient.java:553) ~[kafka-clients-2.3.1.jar:na]
      at org.apache.kafka.clients.producer.internals.Sender.runOnce(Sender.java:335) ~[kafka-clients-2.3.1.jar:na]
      at org.apache.kafka.clients.producer.internals.Sender.run(Sender.java:244) ~[kafka-clients-2.3.1.jar:na]
      at java.lang.Thread.run(Thread.java:748) ~[na:1.8.0_201]
  </code></pre>