Cannot mark DEFAULT_STREAMS_CONFIG_BEAN_NAME as Pr

Question

I just upgraded to spring-boot 2.1.3.RELEASE and I cannot have more than one StreamsBuilderFactoryBean because of this new class/ method (kafkaStreamsFactoryBeanConfigurer requires exactly one factoryBean):

@Configuration
@ConditionalOnClass(StreamsBuilder.class)
@ConditionalOnBean(name = 
KafkaStreamsDefaultConfiguration.DEFAULT_STREAMS_BUILDER_BEAN_NAME)
class KafkaStreamsAnnotationDrivenConfiguration {
 //...
 @Bean
 public KafkaStreamsFactoryBeanConfigurer kafkaStreamsFactoryBeanConfigurer(
        StreamsBuilderFactoryBean factoryBean) {
    return new KafkaStreamsFactoryBeanConfigurer(this.properties, factoryBean);
 }
}

I am getting this error:

Parameter 0 of method kafkaStreamsFactoryBeanConfigurer in org.springframework.boot.autoconfigure.kafka.KafkaStreamsAnnotationDrivenConfiguration required a single bean, but 2 were found:
- &defaultKafkaStreamsBuilder: defined by method 'defaultKafkaStreamsBuilder' in class path resource [com/elsevier/q2c/transaction/snapshot/builder/config/KafkaStreamsConfig.class]
- &snapshotKafkaStreamsBuilder: defined by method 'snapshotKafkaStreamsBuilder' in class path resource [com/elsevier/q2c/transaction/snapshot/builder/config/KafkaStreamsConfig.class]

I would expect to overcome this issue by marking one of the two StreamsBuilderFactoryBean(s) as @Primary (as proposed here). But even if I do:

@Bean(name = KafkaStreamsDefaultConfiguration.DEFAULT_STREAMS_BUILDER_BEAN_NAME)
@Primary
public StreamsBuilderFactoryBean defaultKafkaStreamsBuilder(
        @Qualifier(KafkaStreamsDefaultConfiguration.DEFAULT_STREAMS_CONFIG_BEAN_NAME) KafkaStreamsConfiguration streamsConfiguration) {
    StreamsBuilderFactoryBean streamsBuilderFactoryBean = new StreamsBuilderFactoryBean(streamsConfiguration);
    return streamsBuilderFactoryBean;
}

@Bean(name = SNAPSHOT_STREAMS_BUILDER_BEAN_NAME)
public StreamsBuilderFactoryBean snapshotKafkaStreamsBuilder(
        @Qualifier(SNAPSHOT_STREAMS_CONFIG_BEAN_NAME) KafkaStreamsConfiguration streamsConfiguration) {
    StreamsBuilderFactoryBean streamsBuilderFactoryBean = new StreamsBuilderFactoryBean(streamsConfiguration);
    return streamsBuilderFactoryBean;
}

Still I am getting exactly the same error.

I am thinking that maybe the @Primary makes the constructed beans a Primary. Any help more than appreciated!

EDIT: I circumvented the issue, by removing @EnableKafkaStreams and DEFAULT_STREAMS_BUILDER_BEAN_NAME. As a result, KafkaStreamsFactoryBeanConfigurer does not kick in.

Answer 1

I am not sure why @Primary didn't work. I opened a GitHub issue.

Answer 2

In my case I circumventent the issue by removing @EnableKafkaStreams (i.e. no stream beans are created automatically) and I create manually all needed ones. Looks even better if you have more than one streams as naming can be more destriptive as well.