Producer callback in Spring Cloud Stream using StreamBridge

Question

I'm wondering a way to perform a callback using StreamBridge, I want to do something similar to KafkaTemplate.send that returns a ListenableFuture.

Is it possible with spring cloud stream to publish some events using kafka binder and use a callback like onSuccess and onFailure?

example: producer.send(record, new callback { ... })

Answer 1

You can either set sync on the producer binding and the send will wait internally on the future completion, or you can configure a recordMetadataChannel to get the results of the send asynchronously.

https://docs.spring.io/spring-cloud-stream/docs/current/reference/html/spring-cloud-stream-binder-kafka.html#kafka-producer-properties

recordMetadataChannel

The bean name of a MessageChannel to which successful send results should be sent; the bean must exist in the application context. The message sent to the channel is the sent message (after conversion, if any) with an additional header KafkaHeaders.RECORD_METADATA. The header contains a RecordMetadata object provided by the Kafka client; it includes the partition and offset where the record was written in the topic.

ResultMetadata meta = 
    sendResultMsg.getHeaders().get(KafkaHeaders.RECORD_METADATA, RecordMetadata.class)

Failed sends go the producer error channel (if configured); see Error Channels.

https://docs.spring.io/spring-cloud-stream/docs/current/reference/html/spring-cloud-stream-binder-kafka.html#kafka-error-channels

EDIT

Here's an example:

spring.cloud.stream.bindings.output-out-0.destination=dest1
spring.cloud.stream.bindings.output-out-0.producer.error-channel-enabled=true
spring.cloud.stream.kafka.bindings.output-out-0.producer.record-metadata-channel=meta
spring.cloud.stream.kafka.bindings.output-out-0.producer.configuration.[max.block.ms]=5000
spring.cloud.stream.kafka.bindings.output-out-0.producer.configuration.[request.timeout.ms]=5000
spring.cloud.stream.kafka.bindings.output-out-0.producer.configuration.[retries]=0

@SpringBootApplication
public class So72900966Application {

    public static void main(String[] args) {
        SpringApplication.run(So72900966Application.class, args);
    }

    @Bean
    ApplicationRunner runner(StreamBridge bridge) {
        return args -> {
            bridge.send("output-out-0", "foo");
            System.out.println("Delete topic dest1 from broker; then hit Enter");
            System.in.read();
            bridge.send("output-out-0", "foo");
            Thread.sleep(2_000);
        };
    }

}

@Component
class ResultHandler {

    @ServiceActivator(inputChannel = "meta")
    void meta(Message<?> result) {
        System.out.println(result.getHeaders().get(KafkaHeaders.RECORD_METADATA, RecordMetadata.class));
    }

    @ServiceActivator(inputChannel = "errorChannel")
    void errors(Message<?> error) {
        System.out.println(error);
    }

}

After the first result is received:

kafka-topics.sh --bootstrap-server localhost:9092 --delete --topic dest1

Then hit enter.

Result:

Delete topic dest1 from broker; then hit Enter
dest1-0@0
...
ErrorMessage [payload=org.springframework.integration.kafka.support.KafkaSendFailureException: ...
2022-07-07 13:36:19.185 ERROR 11735 --- [ad | producer-1] o.s.k.support.LoggingProducerListener    : Exception thrown when sending a message with key='null' and payload='byte[3]' to topic dest1:

org.apache.kafka.common.errors.UnknownTopicOrPartitionException: This server does not host this topic-partition.