Spring Kafka - Display Custom Error Message with #Retry - spring-boot

Question

I am currently using Spring Kafka to consume messages from topic along with #Retry of Spring. So basically, I am retrying to process the consumer message in case of an error. But while doing so, I want to avoid the exception message thrown by KafkaMessageListenerContainer. Instead I want to display a custom message. I tried adding an error handler in the ConcurrentKafkaListenerContainerFactory but on doing so, my retry does not get invoked.
Can someone guide me on how to display a custom exception message along with #Retry scenario as well? Below are my code snippets:
ConcurrentKafkaListenerContainerFactory Bean Config
#Bean
ConcurrentKafkaListenerContainerFactory << ? , ? > concurrentKafkaListenerContainerFactory(ConcurrentKafkaListenerContainerFactoryConfigurer configurer, ConsumerFactory < Object, Object > kafkaConsumerFactory) {
ConcurrentKafkaListenerContainerFactory < Object, Object > kafkaListenerContainerFactory =
new ConcurrentKafkaListenerContainerFactory < > ();
configurer.configure(kafkaListenerContainerFactory, kafkaConsumerFactory);
kafkaListenerContainerFactory.setConcurrency(1);
// Set Error Handler
/*kafkaListenerContainerFactory.setErrorHandler(((thrownException, data) -> {
log.info("Retries exhausted);
}));*/
return kafkaListenerContainerFactory;
}
Kafka Consumer
#KafkaListener(
topics = "${spring.kafka.reprocess-topic}",
groupId = "${spring.kafka.consumer.group-id}",
containerFactory = "concurrentKafkaListenerContainerFactory"
)
#Retryable(
include = RestClientException.class,
maxAttemptsExpression = "${spring.kafka.consumer.max-attempts}",
backoff = #Backoff(delayExpression = "${spring.kafka.consumer.backoff-delay}")
)
public void onMessage(ConsumerRecord < String, String > consumerRecord) throws Exception {
// Consume the record
log.info("Consumed Record from topic : {} ", consumerRecord.topic());
// process the record
messageHandler.handleMessage(consumerRecord.value());
}
Below is the exception that I am getting:

Answer 1

You should not use #Retryable as well as the SeekToCurrentErrorHandler (which is now the default, since 2.5; so I presume you are using that version).
Instead, configure a custom SeekToCurrentErrorHandler with max attempts, back off, and retryable exceptions.
That error message is normal; it's logged by the container; it's logging level can be reduced from ERROR to INFO or DEBUG by setting the logLevel property on the SeekToCurrentErrorHandler. You can also add a custom recoverer to it, to log your custom message after the retries are exhausted.

Answer 2

my event retry template,
#Bean(name = "eventRetryTemplate")
public RetryTemplate eventRetryTemplate() {
RetryTemplate template = new RetryTemplate();
ExceptionClassifierRetryPolicy retryPolicy = new ExceptionClassifierRetryPolicy();
Map<Class<? extends Throwable>, RetryPolicy> policyMap = new HashMap<>();
policyMap.put(NonRecoverableException.class, new NeverRetryPolicy());
policyMap.put(RecoverableException.class, new AlwaysRetryPolicy());
retryPolicy.setPolicyMap(policyMap);
ExponentialBackOffPolicy backOffPolicy = new ExponentialBackOffPolicy();
backOffPolicy.setInitialInterval(backoffInitialInterval);
backOffPolicy.setMaxInterval(backoffMaxInterval);
backOffPolicy.setMultiplier(backoffMultiplier);
template.setRetryPolicy(retryPolicy);
template.setBackOffPolicy(backOffPolicy);
return template;
}
my kafka listener using the retry template,
#KafkaListener(
groupId = "${kafka.consumer.group.id}",
topics = "${kafka.consumer.topic}",
containerFactory = "eventContainerFactory")
public void eventListener(ConsumerRecord<String, String>
events,
Acknowledgment acknowledgment) {
eventRetryTemplate.execute(retryContext -> {
retryContext.setAttribute(EVENT, "my-event");
eventConsumer.consume(events, acknowledgment);
return null;
});
}
my kafka consumer properties,
private ConcurrentKafkaListenerContainerFactory<String, String>
getConcurrentKafkaListenerContainerFactory(
KafkaProperties kafkaProperties) {
ConcurrentKafkaListenerContainerFactory<String, String> factory =
new ConcurrentKafkaListenerContainerFactory<>();
factory.getContainerProperties().setAckMode(AckMode.MANUAL_IMMEDIATE);
factory.getContainerProperties().setAckOnError(Boolean.TRUE);
kafkaErrorEventHandler.setCommitRecovered(Boolean.TRUE);
factory.setErrorHandler(kafkaErrorEventHandler);
factory.setConcurrency(1);
factory.getContainerProperties().setAckMode(AckMode.MANUAL_IMMEDIATE);
factory.setConsumerFactory(getEventConsumerFactory(kafkaProperties));
return factory;
}
kafka error event handler is my custom error handler that extends the SeekToCurrentErrorHandler and implements the handle error method some what like this.....
#Override
public void handle(Exception thrownException, List<ConsumerRecord<?, ?>>
records,
Consumer<?, ?> consumer, MessageListenerContainer container) {
log.info("Non recoverable exception. Publishing event to Database");
super.handle(thrownException, records, consumer, container);
ConsumerRecord<String, String> consumerRecord = (ConsumerRecord<String,
String>) records.get(0);
FailedEvent event = createFailedEvent(thrownException, consumerRecord);
failedEventService.insertFailedEvent(event);
log.info("Successfully Published eventId {} to Database...",
event.getEventId());
}
here the failed event service is my custom class again which with put these failed events into a queryable relational DB (I chose this to be my DLQ).