Nservice Bus handler trigger issue

Question

My project is upgrading to use nservice bus version 7. One of the handler is getting executed concurrently. After analysis found that there is a behavior code written and getting executed after handler election. Then next the handler will get executed.This will executed in loop and not getting ended.

public class GatewayPublishBehavior : Behavior<IIncomingLogicalMessageContext>
{

  public override async Task Invoke(IIncomingLogicalMessageContext context, Func<Task> next)
  {
    //// custom logic before calling the next step in the pipeline.
    await next().ConfigureAwait(false); 
    // custom logic after all inner steps in the pipeline completed.
    await context.Publish(context.Message.Instance, 
  this.RetrieveAndGetSendOptions(context));
  }
}

Above is the behavior code. Not sure why the handler getting executed multiple times.

It doesn't look like you posted the full code of the behaviour. — gnud, Mar 06 '20 at 00:18
What @gnud said. The doco for behaviors can be found here : https://docs.particular.net/nservicebus/pipeline/manipulate-with-behaviors — Dennis van der Stelt, Mar 06 '20 at 07:47
If you do `await next()` properly and only once, and no other weird behavior, it should not just execute any handler two times for the same message instance. — Dennis van der Stelt, Mar 06 '20 at 07:48
@gnud the complete code is as below. public override async Task Invoke(IIncomingLogicalMessageContext context, Func next) { //// custom logic before calling the next step in the pipeline. await next().ConfigureAwait(false); // custom logic after all inner steps in the pipeline completed. await context.Publish(context.Message.Instance, this.RetrieveAndGetSendOptions(context)); } — DealZaap India, Mar 06 '20 at 10:01
@DennisvanderStelt the complete code is as below. public override async Task Invoke(IIncomingLogicalMessageContext context, Func next) { //// custom logic before calling the next step in the pipeline. await next().ConfigureAwait(false); // custom logic after all inner steps in the pipeline completed. await context.Publish(context.Message.Instance, this.RetrieveAndGetSendOptions(context)); } — DealZaap India, Mar 06 '20 at 10:01

score 2 · Accepted Answer · answered Mar 07 '20 at 13:01

2

It's exactly like this code

public void Whatever()
{
  Whatever();
}

An endless loop. Just remove the Publish. Why did you add that line? Do you like duplicates? Because you posted the exact same question twice as well. Trying to create a recursive loop inside StackOverflow?

answered Mar 07 '20 at 13:01

Dennis van der Stelt

2,203
16
22

I did on the other post. – Dennis van der Stelt Mar 07 '20 at 16:10
Thanks. I have noticed the same. Thanks for your answer – DealZaap India Mar 08 '20 at 17:42
the context header is getting modified in the behaviour. – DealZaap India Mar 09 '20 at 15:18
1

lol @DennisvanderStelt you are silly ... I've seen this question in more places than just SO... Looks to me like folks need to do some reading up on recursion. – ganjeii Aug 18 '21 at 09:12

score 0 · Answer 2 · edited May 29 '22 at 07:18

0

Every task need to return something.

return Task.CompletedTask;

Just add the upper given code at the bottom of the Handler. It will solve you problem

edited May 29 '22 at 07:18

Valerij Dobler

1,848
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25

answered May 24 '22 at 07:05

Attitudy Amit

15
4

1

Your answer could be improved with additional supporting information. Please [edit] to add further details, such as citations or documentation, so that others can confirm that your answer is correct. You can find more information on how to write good answers [in the help center](/help/how-to-answer). – Community May 24 '22 at 07:47

Nservice Bus handler trigger issue

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