なぜSpring統合フェイルオーバーに例外が表示されないのですか

Question

Spring Integration Dispatcherのフェイルオーバーに問題があり、メッセージハンドラが失敗した場合は例外が表示されます。

私は、単純なSpring統合コンテキストを持っている：

<int:gateway default-request-channel="inboundChannel" 
      service-interface="com.some.gateway.PrinterGateway"/> 

    <int:channel id="inboundChannel"> 
     <int:dispatcher failover="false"/> 
    </int:channel> 

    <!--first Message Handler (broken)-->  
    <bean id="printService" class="com.some.service.PrinterService"/> 

    <int:service-activator input-channel="inboundChannel" 
          method="print" 
          ref="printService"/> 

    <!--second Message Handler--> 
    <bean id="uppercasePrintService" 
      class="com.some.service.UppercasePrinterService"/> 

    <int:service-activator input-channel="inboundChannel" 
          method="printUppercase" 
          ref="uppercasePrintService"/> 

そして、私の壊れたメッセージ・ハンドラ・クラス：私のフェイルオーバーが動作しない理由を

public class PrinterService { 

    public void print(Message<String> message) { 
     throw new RuntimeException("This is error"); 
    } 
} 

1. あなたは私を説明できますか？
2. RuntimeExceptionがスキップされ、メッセージが次のハンドラに配信されたのはなぜですか？

Answer 1

私にとってはうまくいきます。

達成しようとしていることは明確ではありません。おそらくあなたはロードバランシングを誤解しているでしょうか？

デフォルトでは、ロードバランシング戦略はラウンドロビン方式です。つまり、最初のメッセージが失敗したエンドポイントに送られます。 2番目は良いエンドポイントに移動します。 メッセージが交互に表示されます。

19:23:16.867 [main] DEBUG org.springframework.integration.channel.DirectChannel - preSend on channel 'org.springframework.integration.channel.DirectChannel@1794d431', message: GenericMessage [payload=foo, headers={id=9c3b1493-0a9a-e324-6da3-262079677ed0, timestamp=1494199396867}] 
org.springframework.messaging.MessageDeliveryException: failed to send Message to channel 'null'; nested exception is java.lang.RuntimeException: foo, failedMessage=GenericMessage [payload=foo, headers={id=9c3b1493-0a9a-e324-6da3-262079677ed0, timestamp=1494199396867}] 
    at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:449) 
    at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:373) 
    at com.example.So43836561Application.main(So43836561Application.java:16) 
Caused by: java.lang.RuntimeException: foo 
    at com.example.So43836561Application.lambda$0(So43836561Application.java:13) 
    at com.example.So43836561Application$$Lambda$1/1121454968.handleMessage(Unknown Source) 
    at org.springframework.integration.dispatcher.UnicastingDispatcher.doDispatch(UnicastingDispatcher.java:160) 
    at org.springframework.integration.dispatcher.UnicastingDispatcher.dispatch(UnicastingDispatcher.java:121) 
    at org.springframework.integration.channel.AbstractSubscribableChannel.doSend(AbstractSubscribableChannel.java:89) 
    at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:423) 
    ... 2 more 
19:23:18.875 [main] DEBUG org.springframework.integration.channel.DirectChannel - preSend on channel 'org.springframework.integration.channel.DirectChannel@1794d431', message: GenericMessage [payload=bar, headers={id=90aaa16c-a8c1-9162-ba8f-532fa3201c7f, timestamp=1494199398875}] 
Second Service: GenericMessage [payload=bar, headers={id=90aaa16c-a8c1-9162-ba8f-532fa3201c7f, timestamp=1494199398875}] 
19:23:18.876 [main] DEBUG org.springframework.integration.channel.DirectChannel - postSend (sent=true) on channel 'org.springframework.integration.channel.DirectChannel@1794d431', message: GenericMessage [payload=bar, headers={id=90aaa16c-a8c1-9162-ba8f-532fa3201c7f, timestamp=1494199398875}] 

NONEロードバランス戦略を使用すると、すべてのメッセージが失敗したメッセージに移動します。

19:26:38.005 [main] DEBUG org.springframework.integration.channel.DirectChannel - preSend on channel 'org.springframework.integration.channel.DirectChannel@7d9d1a19', message: GenericMessage [payload=foo, headers={id=6a69efe9-dbbd-c79b-41a9-6964fd4c8ccc, timestamp=1494199598004}] 
org.springframework.messaging.MessageDeliveryException: failed to send Message to channel 'null'; nested exception is java.lang.RuntimeException: foo, failedMessage=GenericMessage [payload=foo, headers={id=6a69efe9-dbbd-c79b-41a9-6964fd4c8ccc, timestamp=1494199598004}] 
    at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:449) 
    at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:373) 
    at com.example.So43836561Application.main(So43836561Application.java:16) 
Caused by: java.lang.RuntimeException: foo 
    at com.example.So43836561Application.lambda$0(So43836561Application.java:13) 
    at com.example.So43836561Application$$Lambda$1/2009787198.handleMessage(Unknown Source) 
    at org.springframework.integration.dispatcher.UnicastingDispatcher.doDispatch(UnicastingDispatcher.java:160) 
    at org.springframework.integration.dispatcher.UnicastingDispatcher.dispatch(UnicastingDispatcher.java:121) 
    at org.springframework.integration.channel.AbstractSubscribableChannel.doSend(AbstractSubscribableChannel.java:89) 
    at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:423) 
    ... 2 more 
19:26:40.009 [main] DEBUG org.springframework.integration.channel.DirectChannel - preSend on channel 'org.springframework.integration.channel.DirectChannel@7d9d1a19', message: GenericMessage [payload=bar, headers={id=9428a10e-3a17-79d5-e4bd-731fc88ef0fe, timestamp=1494199600008}] 
Exception in thread "main" org.springframework.messaging.MessageDeliveryException: failed to send Message to channel 'null'; nested exception is java.lang.RuntimeException: foo, failedMessage=GenericMessage [payload=bar, headers={id=9428a10e-3a17-79d5-e4bd-731fc88ef0fe, timestamp=1494199600008}] 
    at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:449) 
    at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:373) 
    at com.example.So43836561Application.main(So43836561Application.java:22) 
Caused by: java.lang.RuntimeException: foo 
    at com.example.So43836561Application.lambda$0(So43836561Application.java:13) 
    at com.example.So43836561Application$$Lambda$1/2009787198.handleMessage(Unknown Source) 
    at org.springframework.integration.dispatcher.UnicastingDispatcher.doDispatch(UnicastingDispatcher.java:160) 
    at org.springframework.integration.dispatcher.UnicastingDispatcher.dispatch(UnicastingDispatcher.java:121) 
    at org.springframework.integration.channel.AbstractSubscribableChannel.doSend(AbstractSubscribableChannel.java:89) 
    at org.springframework.integration.channel.AbstractMessageChannel.send(AbstractMessageChannel.java:423) 
    ... 2 more 

これは問題ではない場合があります。同じIDの別のチャネルビーンがありますか？

org.springframework.integrationのDEBUGロギングをオンにしても、何が起こっているかがわかります。

EDIT

あなたは非同期ゲートウェイを使用しているので（Future<?>を返します）あなたは

@Override 
public void run(ApplicationArguments applicationArguments) throws Exception { 
    List<Future<Message<String>>> futures = new ArrayList<>(); 
    for (int i = 0; i < 10; i++) { 
     Message<String> message = MessageBuilder.withPayload("Some payload that created for message id: " + i) 
       .build(); 
     log.info("Sending message " + i); 
     futures.add(gateway.print(message)); 
    } 
    futures.forEach(f -> { 
     try { 
      System.out.println(f.get()); 
     } 
     catch (ExecutionException e) { 
      System.out.println(e.getCause().getMessage()); 
     } 
     catch (InterruptedException e) { 
      Thread.currentThread().interrupt(); 
     } 
    }); 
} 

と

public String printUppercase(Message<String> message) { 
    log.info(message.getPayload().toUpperCase()); 
    return message.getPayload().toUpperCase(); 
} 

...例外を取得し、結果を検討する必要があります結果：

This is error 
GenericMessage [payload=SOME PAYLOAD THAT CREATED FOR MESSAGE ID: 1, headers={id=229ad2ee-f424-61da-a9bc-a631de9bd5d0, timestamp=1494360966556}] 
GenericMessage [payload=SOME PAYLOAD THAT CREATED FOR MESSAGE ID: 2, headers={id=7e2c45c4-2c7b-f3f3-243d-56d9de33375f, timestamp=1494360966556}] 
This is error 
This is error 
This is error 
GenericMessage [payload=SOME PAYLOAD THAT CREATED FOR MESSAGE ID: 6, headers={id=79f4ef60-9dea-60f3-3972-a9eefde67ebf, timestamp=1494360966556}] 
GenericMessage [payload=SOME PAYLOAD THAT CREATED FOR MESSAGE ID: 7, headers={id=626d1347-e5bd-ec4c-b153-71174cc7f18d, timestamp=1494360966556}] 
This is error