Question

我正在尝试实施提议的SCS聚合，但我不确定理解它们的真正目的，因为结果让我感到惊讶。首先，这是代码......

来源，要安排的消息提供者：

@SpringBootApplication
@EnableBinding(Source.class)
public class SourceApplication {

    private final Logger logger = LoggerFactory.getLogger(SourceApplication.class);

    @Bean
    @InboundChannelAdapter(Source.OUTPUT)
    public MessageSource<String> createMessage() {
        return () -> {
            String payload = now().toString();
            logger.warn("Sent: " + payload);
            return new GenericMessage<>(payload);
        };
    }
}

然后是一个简单的处理器（变压器）：

@SpringBootApplication
@EnableBinding(Processor.class)
public class ProcessorApplication {

    @Transformer(inputChannel = Processor.INPUT,
                 outputChannel = Processor.OUTPUT)
    public String processMessage(String payload) {
        return payload + " is the time.";
    }
}

这是最终消费者（接收器）：

@SpringBootApplication
@EnableBinding(Sink.class)
public class SinkApplication {

    private final Logger logger = LoggerFactory.getLogger(SinkApplication.class);

    @ServiceActivator(inputChannel = Sink.INPUT)
    public void loggerSink(Object payload) {
        logger.warn("Received: " + payload);
    }
}

最后，汇总将这三者联系起来：

@SpringBootApplication
public class SampleAggregateApplication {

    public static void main(String[] args) {
        new AggregateApplicationBuilder().web(false)
            .from(SourceApplication.class)
                .args("--spring.cloud.stream.bindings.output.destination=step1", "--fixedDelay=5000")
            .via(ProcessorApplication.class)
                .args("--spring.cloud.stream.bindings.input.destination=step1",
                      "--spring.cloud.stream.bindings.output.destination=step2")
            .to(SinkApplication.class)
                .args("--spring.cloud.stream.bindings.input.destination=step2")
        .run(args);
    }
}

启动聚合时，这些是检索到的跟踪的摘录：

2017-02-03 09:59:13.428  WARN 18688 --- [ask-scheduler-8] c.p.demo.aggregator.SourceApplication    : Sent: 2017-02-03T09:59:13.428
2017-02-03 09:59:13.949  WARN 18688 --- [ask-scheduler-3] c.p.demo.aggregator.SourceApplication    : Sent: 2017-02-03T09:59:13.949
2017-02-03 09:59:13.949  WARN 18688 --- [ask-scheduler-3] c.p.demo.aggregator.SinkApplication      : Received: 2017-02-03T09:59:13.949
2017-02-03 09:59:13.996  WARN 18688 --- [ask-scheduler-9] c.p.demo.aggregator.SourceApplication    : Sent: 2017-02-03T09:59:13.996
2017-02-03 09:59:14.430  WARN 18688 --- [ask-scheduler-2] c.p.demo.aggregator.SourceApplication    : Sent: 2017-02-03T09:59:14.430
2017-02-03 09:59:14.956  WARN 18688 --- [sk-scheduler-10] c.p.demo.aggregator.SourceApplication    : Sent: 2017-02-03T09:59:14.956
2017-02-03 09:59:14.956  WARN 18688 --- [sk-scheduler-10] c.p.demo.aggregator.SinkApplication      : Received: 2017-02-03T09:59:14.956 is the time.
2017-02-03 09:59:14.999  WARN 18688 --- [ask-scheduler-5] c.p.demo.aggregator.SourceApplication    : Sent: 2017-02-03T09:59:14.999
2017-02-03 09:59:15.432  WARN 18688 --- [ask-scheduler-6] c.p.demo.aggregator.SourceApplication    : Sent: 2017-02-03T09:59:15.432
2017-02-03 09:59:15.961  WARN 18688 --- [ask-scheduler-7] c.p.demo.aggregator.SourceApplication    : Sent: 2017-02-03T09:59:15.961
2017-02-03 09:59:15.961  WARN 18688 --- [ask-scheduler-7] c.p.demo.aggregator.SinkApplication      : Received: 2017-02-03T09:59:15.961
2017-02-03 09:59:16.000  WARN 18688 --- [ask-scheduler-1] c.p.demo.aggregator.SourceApplication    : Sent: 2017-02-03T09:59:16
2017-02-03 09:59:16.001  WARN 18688 --- [ask-scheduler-1] c.p.demo.aggregator.SinkApplication      : Received: 2017-02-03T09:59:16
2017-02-03 09:59:16.437  WARN 18688 --- [ask-scheduler-4] c.p.demo.aggregator.SourceApplication    : Sent: 2017-02-03T09:59:16.437
2017-02-03 09:59:16.966  WARN 18688 --- [ask-scheduler-8] c.p.demo.aggregator.SourceApplication    : Sent: 2017-02-03T09:59:16.966
2017-02-03 09:59:17.006  WARN 18688 --- [ask-scheduler-3] c.p.demo.aggregator.SourceApplication    : Sent: 2017-02-03T09:59:17.006
2017-02-03 09:59:17.006  WARN 18688 --- [ask-scheduler-3] c.p.demo.aggregator.SinkApplication      : Received: 2017-02-03T09:59:17.006
2017-02-03 09:59:17.443  WARN 18688 --- [ask-scheduler-9] c.p.demo.aggregator.SourceApplication    : Sent: 2017-02-03T09:59:17.443
2017-02-03 09:59:17.971  WARN 18688 --- [ask-scheduler-2] c.p.demo.aggregator.SourceApplication    : Sent: 2017-02-03T09:59:17.971
2017-02-03 09:59:17.971  WARN 18688 --- [ask-scheduler-2] c.p.demo.aggregator.SinkApplication      : Received: 2017-02-03T09:59:17.971
2017-02-03 09:59:18.007  WARN 18688 --- [sk-scheduler-10] c.p.demo.aggregator.SourceApplication    : Sent: 2017-02-03T09:59:18.007
2017-02-03 09:59:18.448  WARN 18688 --- [ask-scheduler-5] c.p.demo.aggregator.SourceApplication    : Sent: 2017-02-03T09:59:18.448
2017-02-03 09:59:18.976  WARN 18688 --- [ask-scheduler-6] c.p.demo.aggregator.SourceApplication    : Sent: 2017-02-03T09:59:18.976
2017-02-03 09:59:18.976  WARN 18688 --- [ask-scheduler-6] c.p.demo.aggregator.SinkApplication      : Received: 2017-02-03T09:59:18.976 is the time.
2017-02-03 09:59:19.012  WARN 18688 --- [ask-scheduler-7] c.p.demo.aggregator.SourceApplication    : Sent: 2017-02-03T09:59:19.012
2017-02-03 09:59:19.449  WARN 18688 --- [ask-scheduler-1] c.p.demo.aggregator.SourceApplication    : Sent: 2017-02-03T09:59:19.449
2017-02-03 09:59:19.982  WARN 18688 --- [ask-scheduler-4] c.p.demo.aggregator.SourceApplication    : Sent: 2017-02-03T09:59:19.982
2017-02-03 09:59:19.982  WARN 18688 --- [ask-scheduler-4] c.p.demo.aggregator.SinkApplication      : Received: 2017-02-03T09:59:19.982
2017-02-03 09:59:20.018  WARN 18688 --- [ask-scheduler-8] c.p.demo.aggregator.SourceApplication    : Sent: 2017-02-03T09:59:20.018
2017-02-03 09:59:20.018  WARN 18688 --- [ask-scheduler-8] c.p.demo.aggregator.SinkApplication      : Received: 2017-02-03T09:59:20.018
2017

我原本预计每条消息都会遵循定义的周期：source-processor-sink。我们可以看到3个消息中至少有2个丢失，并且4个消息中只有1个被转换。注意：第二次尝试添加了通道目的地，以避免应用程序之间混淆（使用相同的RabbitMQ中间件）。

有人可以告诉我，如果我正确地取消了聚合目的并做了正确的事情来实现它吗？提前谢谢。

Answer 1

有几件事：

您不应该为您的应用程序指定目的地，因为作为聚合的一部分的应用程序通过内部渠道进行通信，而不是通过代理;
其次（不幸的是，这是我们的文档没有指定的内容） - 在每个聚合组件定义上使用@SpringBootApplication时，聚合的不同部分必须属于不同的Java包。在您的情况下，您会在各种渠道上获得多个消费者，而不是您期望的链接。将Source，Transformer和Sink移动到单独的包应该适合您。另外，添加了https://github.com/spring-cloud/spring-cloud-stream/issues/785来跟踪此内容。

Spring Cloud Stream - 聚合

1 个答案: