About the roll back and signal boundary event

[LiveInTheDream]

Continuing the discussion from Why did this error event not trigger:

Hello, I have another problem that I cannot solve.
It’s my bpmn:

In the second serviceTask, i throw an exception. The error boundary event can be triggered and the process can be rolled back to the userTask. But i want to send a signal in the error boundary event and the signal boundary event can be triggered. Now the exception seems to affect my signal sending. So how should I solve it or redesign the bpmn?

The second serviceTask

The error boundary event listener

The signal boundary event listener

[WilliamR.Alves]

Hello my friend!

I don’t know if I understood your question correctly… see if I understood correctly:

• Do you want to trigger your Error boundary event, in addition to following the error flow, you also want to execute the Signal Event?

If so… you will need to change your Signal Event to “non-interrupting”… so you will have one token following the Error Boundary Event and another token starting at the Signal Event.

I’m sorry if I didn’t understand your question correctly, maybe my English isn’t that good…

But if I misunderstood, I would be happy if you could explain it to me better so I can help!

William Robert Alves

[LiveInTheDream]

Thanks for your answer.I accidentally created multiple process instances, and I found that the signal sent by this process instance was received by another instance.How to avoid it？

[WilliamR.Alves]

Hello!

The signal event is generally for triggering for “multiple instances”… the “message event” is for triggering for a single instance.

If you always want to send to a single instance, you must use the message event to correlate with the desired instance.

The signal event can be used to trigger all instances or some according to rules specified in the code.

Below are the links to the official Camunda doc, where you can see better how to use and implement a signal event or message event.

Signal Events | docs.camunda.org

Message Events | docs.camunda.org

Hope this helps.

William Robert Alves