Dispatcher 没有频道订阅者 - spring-cloud-stream-kafka

Question

升级到 Spring Boot 2、Reactor 3.5、kafka-binder 2.0.0 RELEASE 和 kafka-client 1.0.1 后，其中一个模块不起作用。 我花了 5 天时间完成并阅读了所有相关主题，但找不到这种行为的原因。

主要类：

@Slf4j
@EnableI18N
@EnableSideBar
@ComponentScan
@SpringBootConfiguration
@EnableConfigurationProperties
@EnableAspectJAutoProxy(proxyTargetClass = true)
public class View
{
    public static void main(String[] args)
    {
        new SpringApplicationBuilder(View.class)
            .profiles("production")
            .bannerMode(Banner.Mode.OFF)
            .headless(true)
            .application()
            .run(args);

        log.info("\nhttp://localhost:8083/\n");
    }
}

配置标记：

@Configuration
@Profile("production")
@EnableBinding(OffersChannel.class)
class ProductionOffersConfiguration
{
}

通道接口：

public interface OffersChannel
{
    String OFFERS_OBTAIN = "offersObtain";
    String OFFERS_OBTAIN_REQUEST= "offersObtainRequest";

    @Input(OFFERS_OBTAIN)
    SubscribableChannel offersChannel();

    @Output(OFFERS_OBTAIN_REQUEST)
    MessageChannel offersRequestChannel();
}

还有 AdminUI 类，在更新依赖项之前很重要，当这个类被初始化时，我能够在控制台中看到一个日志，上面写着我订阅了频道，现在什么都没有发生：

@Slf4j
@Push
@Theme("${view.default-theme}")
@SpringUI(path = WebsiteMapping.ADMIN)
@RequiredArgsConstructor
public class AdminUI extends UI
{
    MessageChannel offersObtainRequest;
    Grid<Ad> adGrid = createAdGrid();
    private List<Ad> ads = new LinkedList<>();
    ConnectionService connectionService;

    @Override
    @SneakyThrows
    protected void init(VaadinRequest vaadinRequest)
    {
        setContent(splitPane());
        adGrid.setItems(ads);
    }

    private VerticalSplitPanel splitPane()
    {
        VerticalSplitPanel verticalSplitPanel = new VerticalSplitPanel();
        verticalSplitPanel.setSplitPosition(10, Unit.PERCENTAGE);
        verticalSplitPanel.setFirstComponent(buttonsLayout());
        verticalSplitPanel.setSecondComponent(adGrid);

        return verticalSplitPanel;
    }

    private Layout buttonsLayout()
    {
        HorizontalLayout layout = new HorizontalLayout();
        layout.setMargin(true);

        layout.addComponent(requestMoreOffersButton());

        ThemeSelectorComboBox themeSelectorComboBox = new ThemeSelectorComboBox();
        layout.addComponent(themeSelectorComboBox);
        layout.setComponentAlignment(themeSelectorComboBox, Alignment.MIDDLE_RIGHT);

        return layout;
    }

    @PostConstruct
    private void createGridProperties()
    {
        adGrid.setSizeFull();
        adGrid.addColumn(Ad::getTitle).setCaption("Title");
        adGrid.addColumn(Ad::getLocation).setCaption("Location");
        adGrid.addColumn(Ad::getHref).setCaption("Href");
    }

    @StreamListener
    public void fetchAdsFrom(@Input(OffersChannel.OFFERS_OBTAIN) Flux<Ad> fluxAd)
    {
        fluxAd.subscribe(this::displayOfferInGrid);
    }

    private void displayOfferInGrid(Ad ad)
    {
        ads.add(ad);
        adGrid.setItems(ads);
    }

    private Button requestMoreOffersButton()
    {
        return new Button("Request 10 more offers", this::requestMoreOffers);
    }

    private Button startServiceButton(String caption, String url, String message)
    {
        return new Button(caption, buttonClickedEvent -> startService(url, message));
    }

    private void startService(String url, String message)
    {
        ConnectionRequest startProviderRequest = ConnectionRequest
            .builder()
            .url(url)
            .build();

        connectionService
            .getForHtml(startProviderRequest)
            .thenAccept(serviceStarted -> Notification.show(message));
    }

    private void requestMoreOffers(Event event)

    {
        offersObtainRequest.send(new GenericMessage(new AdBroadcastRequest(ads.size(),10)));
    }

    private Grid<Ad> createAdGrid()
    {
        return new Grid<>();
    }
}

应用程序.yml：

spring:
    cloud:
        stream:
            bindings:
                offersObtainRequest:
                   destination: adsBroadcastRequestes
                   binder: kafka
                   group: adsBroadcastRequestsProducer
                offersObtain:
                   destination: adsBroadcast
                   binder: kafka
                   group: adsConsumer

堆栈跟踪：

2018-04-07 11:27:12.010 DEBUG o.s.retry.support.RetryTemplate         : Retry: count=0
2018-04-07 11:27:12.010 DEBUG o.s.integration.channel.DirectChannel   : preSend on channel 'offersObtain', message: GenericMessage [payload=byte[227], headers={kafka_offset=12, scst_nativeHeadersPresent=true, kafka_consumer=org.apache.kafka.clients.consumer.KafkaConsumer@11d6acc8, deliveryAttempt=1, kafka_timestampType=CREATE_TIME, kafka_receivedMessageKey=null, kafka_receivedPartitionId=0, contentType=application/json, kafka_receivedTopic=adsBroadcast, kafka_receivedTimestamp=1523093225984}]
2018-04-07 11:27:12.010 DEBUG o.s.r.backoff.ExponentialBackOffPolicy  : Sleeping for 1000
2018-04-07 11:27:13.011 DEBUG o.s.retry.support.RetryTemplate         : Checking for rethrow: count=1
2018-04-07 11:27:13.011 DEBUG o.s.retry.support.RetryTemplate         : Retry: count=1
2018-04-07 11:27:13.011 DEBUG o.s.integration.channel.DirectChannel   : preSend on channel 'offersObtain', message: GenericMessage [payload=byte[227], headers={kafka_offset=12, scst_nativeHeadersPresent=true, kafka_consumer=org.apache.kafka.clients.consumer.KafkaConsumer@11d6acc8, deliveryAttempt=2, kafka_timestampType=CREATE_TIME, kafka_receivedMessageKey=null, kafka_receivedPartitionId=0, contentType=application/json, kafka_receivedTopic=adsBroadcast, kafka_receivedTimestamp=1523093225984}]
2018-04-07 11:27:13.011 DEBUG o.s.r.backoff.ExponentialBackOffPolicy  : Sleeping for 2000
2018-04-07 11:27:13.909 DEBUG o.a.k.c.c.internals.AbstractCoordinator : [Consumer clientId=consumer-2, groupId=adsConsumer] Sending Heartbeat request to coordinator Kacper-PC:9092 (id: 2147483647 rack: null)
2018-04-07 11:27:14.138 DEBUG o.a.k.c.c.internals.AbstractCoordinator : [Consumer clientId=consumer-2, groupId=adsConsumer] Received successful Heartbeat response
2018-04-07 11:27:15.011 DEBUG o.s.retry.support.RetryTemplate         : Checking for rethrow: count=2
2018-04-07 11:27:15.011 DEBUG o.s.retry.support.RetryTemplate         : Retry: count=2
2018-04-07 11:27:15.011 DEBUG o.s.integration.channel.DirectChannel   : preSend on channel 'offersObtain', message: GenericMessage [payload=byte[227], headers={kafka_offset=12, scst_nativeHeadersPresent=true, kafka_consumer=org.apache.kafka.clients.consumer.KafkaConsumer@11d6acc8, deliveryAttempt=3, kafka_timestampType=CREATE_TIME, kafka_receivedMessageKey=null, kafka_receivedPartitionId=0, contentType=application/json, kafka_receivedTopic=adsBroadcast, kafka_receivedTimestamp=1523093225984}]
2018-04-07 11:27:15.011 DEBUG o.s.retry.support.RetryTemplate         : Checking for rethrow: count=3
2018-04-07 11:27:15.011 DEBUG o.s.retry.support.RetryTemplate         : Retry failed last attempt: count=3
2018-04-07 11:27:15.012 DEBUG o.s.i.h.a.ErrorMessageSendingRecoverer  : Sending ErrorMessage: failedMessage: GenericMessage [payload=byte[227], headers={kafka_offset=12, scst_nativeHeadersPresent=true, kafka_consumer=org.apache.kafka.clients.consumer.KafkaConsumer@11d6acc8, deliveryAttempt=3, kafka_timestampType=CREATE_TIME, kafka_receivedMessageKey=null, kafka_receivedPartitionId=0, contentType=application/json, kafka_receivedTopic=adsBroadcast, kafka_receivedTimestamp=1523093225984}]

org.springframework.messaging.MessageDeliveryException: Dispatcher has no subscribers for channel 'application.offersObtain'.; nested exception is org.springframework.integration.MessageDispatchingException: Dispatcher has no subscribers, failedMessage=GenericMessage [payload=byte[227], headers={kafka_offset=12, scst_nativeHeadersPresent=true, kafka_consumer=org.apache.kafka.clients.consumer.KafkaConsumer@11d6acc8, deliveryAttempt=3, kafka_timestampType=CREATE_TIME, kafka_receivedMessageKey=null, kafka_receivedPartitionId=0, contentType=application/json, kafka_receivedTopic=adsBroadcast, kafka_receivedTimestamp=1523093225984}]
    at org.springframework.integration.channel.AbstractSubscribableChannel.doSend(AbstractSubscribableChannel.java:77) ~[spring-integration-core-5.0.3.RELEASE.jar:5.0.3.RELEASE]
    at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:463) ~[spring-integration-core-5.0.3.RELEASE.jar:5.0.3.RELEASE]
    at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:407) ~[spring-integration-core-5.0.3.RELEASE.jar:5.0.3.RELEASE]
    at org.springframework.messaging.core.GenericMessagingTemplate.doSend(GenericMessagingTemplate.java:181) ~[spring-messaging-5.0.4.RELEASE.jar:5.0.4.RELEASE]
    at org.springframework.messaging.core.GenericMessagingTemplate.doSend(GenericMessagingTemplate.java:160) ~[spring-messaging-5.0.4.RELEASE.jar:5.0.4.RELEASE]
    at org.springframework.messaging.core.GenericMessagingTemplate.doSend(GenericMessagingTemplate.java:47) ~[spring-messaging-5.0.4.RELEASE.jar:5.0.4.RELEASE]
    at org.springframework.messaging.core.AbstractMessageSendingTemplate.send(AbstractMessageSendingTemplate.java:108) ~[spring-messaging-5.0.4.RELEASE.jar:5.0.4.RELEASE]
    at org.springframework.integration.endpoint.MessageProducerSupport.sendMessage(MessageProducerSupport.java:203) ~[spring-integration-core-5.0.3.RELEASE.jar:5.0.3.RELEASE]
    at org.springframework.integration.kafka.inbound.KafkaMessageDrivenChannelAdapter.access$300(KafkaMessageDrivenChannelAdapter.java:70) ~[spring-integration-kafka-3.0.3.RELEASE.jar:3.0.3.RELEASE]
    at org.springframework.integration.kafka.inbound.KafkaMessageDrivenChannelAdapter$IntegrationRecordMessageListener.onMessage(KafkaMessageDrivenChannelAdapter.java:387) ~[spring-integration-kafka-3.0.3.RELEASE.jar:3.0.3.RELEASE]
    at org.springframework.integration.kafka.inbound.KafkaMessageDrivenChannelAdapter$IntegrationRecordMessageListener.onMessage(KafkaMessageDrivenChannelAdapter.java:364) ~[spring-integration-kafka-3.0.3.RELEASE.jar:3.0.3.RELEASE]
    at org.springframework.kafka.listener.adapter.RetryingMessageListenerAdapter.lambda$onMessage$0(RetryingMessageListenerAdapter.java:120) [spring-kafka-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at org.springframework.retry.support.RetryTemplate.doExecute(RetryTemplate.java:287) [spring-retry-1.2.2.RELEASE.jar:na]
    at org.springframework.retry.support.RetryTemplate.execute(RetryTemplate.java:211) [spring-retry-1.2.2.RELEASE.jar:na]
    at org.springframework.kafka.listener.adapter.RetryingMessageListenerAdapter.onMessage(RetryingMessageListenerAdapter.java:114) [spring-kafka-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at org.springframework.kafka.listener.adapter.RetryingMessageListenerAdapter.onMessage(RetryingMessageListenerAdapter.java:40) [spring-kafka-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at org.springframework.kafka.listener.KafkaMessageListenerContainer$ListenerConsumer.doInvokeRecordListener(KafkaMessageListenerContainer.java:1001) [spring-kafka-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at org.springframework.kafka.listener.KafkaMessageListenerContainer$ListenerConsumer.doInvokeWithRecords(KafkaMessageListenerContainer.java:981) [spring-kafka-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at org.springframework.kafka.listener.KafkaMessageListenerContainer$ListenerConsumer.invokeRecordListener(KafkaMessageListenerContainer.java:932) [spring-kafka-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at org.springframework.kafka.listener.KafkaMessageListenerContainer$ListenerConsumer.invokeListener(KafkaMessageListenerContainer.java:801) [spring-kafka-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at org.springframework.kafka.listener.KafkaMessageListenerContainer$ListenerConsumer.run(KafkaMessageListenerContainer.java:689) [spring-kafka-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [na:1.8.0_151]
    at java.util.concurrent.FutureTask.run(FutureTask.java:266) [na:1.8.0_151]
    at java.lang.Thread.run(Thread.java:748) [na:1.8.0_151]
Caused by: org.springframework.integration.MessageDispatchingException: Dispatcher has no subscribers
    at org.springframework.integration.dispatcher.UnicastingDispatcher.doDispatch(UnicastingDispatcher.java:138) ~[spring-integration-core-5.0.3.RELEASE.jar:5.0.3.RELEASE]
    at org.springframework.integration.dispatcher.UnicastingDispatcher.dispatch(UnicastingDispatcher.java:105) ~[spring-integration-core-5.0.3.RELEASE.jar:5.0.3.RELEASE]
    at org.springframework.integration.channel.AbstractSubscribableChannel.doSend(AbstractSubscribableChannel.java:73) ~[spring-integration-core-5.0.3.RELEASE.jar:5.0.3.RELEASE]
    ... 23 common frames omitted

Answer 1

嗯，里面有很多事情要做。 我的意思是所有非 Spring-Cloud-Stream 的东西。 . . 让人很难跟上。 在任何情况下，您的@StreamListener都没有在任何 Spring 托管配置类中定义，因此不会被选中。 您可以将其移动到ProductionOffersConfiguration或View或任何其他 Spring 托管配置类。

另外，请考虑阅读此快速教程https://docs.spring.io/spring-cloud-stream/docs/Elmhurst.RELEASE/reference/htmlsingle/#_quick_start（5分钟）以更好地了解 spring-cloud-流

Answer 2

就我而言，我使用@Input通道声明了 spring-cloud-steam 接口

 @Input("in")
 SubscribableChannel inbound();

但我没有使用任何@StreamListener 来处理这个目标，所以我得到了这样的错误

MessageDeliveryException: Dispatcher has no subscribers for channel

解决方案：我删除了@Input 声明，只留下@Output("out") 一个。

仅供参考：我的输入在其他单独的服务中配置。

Answer 3

您可以使用@StreamListener注释，但在注释中使用目标参数。

@StreamListener(target = OffersChannel.OFFERS_OBTAIN)
public void fetchAdsFrom(@Payload Flux<Ad> fluxAd, @Header final String someHeader)
{
    fluxAd.subscribe(this::displayOfferInGrid);
}

对我有用，类似于你的设置（而不是 Flux 我收到一个 JSON - 字符串）。

可能是您必须为 Flux 消息编写自己的转换器，我不确定。

Answer 4

我花了几个小时试图找出那些“调度程序没有订阅者”错误背后的真正问题。

就我而言，问题是 Kafka 存储了一些历史节点 id (1001)，而所有主题都使用 1003 作为领导者 id，这就是无法发送消息的原因。 必须手动擦除所有这些才能使其正常工作。

虽然它非常适合我的本地设置作为快速修复，但在生产环境中不太可能是正确的方法。 对于永久解决方案（为您的经纪人设置静态 ID），您可以尝试查看此答案。