Receivetask in camunda is not working as expected - spring

Question

We have been using camunda 7.4 version in most of our projects along with camunda-bpm-spring-boot-starter 1.1.0.
We have a project where in the camunda flow we try to publish a message to a message broker which internally is consumed by another system and re-publish a new message to the same message broker. Then we trigger a receiveTask to receive that message and process further. To listen to the incoming message we use org.springframework.amqp.core.MessageListener and we define the message co-relation for receiveTask within the onMessage() method. But we get below error in doing so
org.camunda.bpm.engine.MismatchingMessageCorrelationException: Cannot correlate message 'ReceiveAmsharedResponse': No process definition or execution matches the parameters
We are trying to figure where the problem is? Is it in the version of camunda we are using or the problem is with the usage of receiveTask. We tried all approaches defined in https://docs.camunda.org/manual/7.4/reference/bpmn20/tasks/receive-task/ but no luck.
For the method createMessageCorrelation we get above error. And for other methods we get a NPE as EventSubscription/Execution objects are null.
Sample Camunda flow receiveTask Usage is as below:
<bpmn2:receiveTask id="ReceiveTask" name="Receive Task" messageRef="Message_06nl07f">
<bpmn2:incoming>SequenceFlow_xyz</bpmn2:incoming>
<bpmn2:outgoing>SequenceFlow_190m9nx</bpmn2:outgoing>
</bpmn2:receiveTask>
......
......
<bpmn2:message id="Message_06nl07f" name="Message" />
And sample message co-relation code:
class XYZ implements MessageListener {
onMessage() {
runtimeService.createMessageCorrelation("Message")
.processInstanceBusinessKey(resourceId)
.setVariable(ACTIVITY_RESULT, activityResult)
.correlate();
}
Any help would be appreciated?
Thanks,
Viswanath

Answer 1

Assuming your process looks something like this:
O -- ( M ) -- ( M ) -- O
send receive
If the response message is send very fast, it possible that the onMessage and message correlation is executed before the message event subscription is persisted in the database. Basically the message arrives while the send task is stil being executed.
One way to avoid this would be to create the message subscription in parallel with sending the event:
O -- + -- ( M ) -- + -- O
| send |
`----( M ) --´
receive

Answer 2

Regarding to the given exception message which is :
org.camunda.bpm.engine.MismatchingMessageCorrelationException: Cannot correlate message 'ReceiveAmsharedResponse': No process definition or execution matches the parameters
I assume that you correlate a message with the name ReceiveAmsharedResponse, but you defined a Message with a different name for your ReceiveTask.
Changing the definition of your Message to the following should work:
<bpmn2:message id="Message_06nl07f" name="ReceiveAmsharedResponse" />

Answer 3

Assuming your process looks something like this:
O -- ( M ) -- ( M ) -- O
send receive
This error means that a response was received "earlier" than the request was sent.
And by sent, I mean the whole transaction of the send-request process.
So, in other words, because of the fast response, there is no commited transaction in Camunda Database for the send-request process. Thus, when camunda processes the response-received process, it is not possible to correlate the response-received with the send-request.
One suggested solution is to use Async Continuations that Camunda offers and you might check in their official website. More specifically, you might use Async Before at the send-request level:
( M )
send
Async Before will save the transaction in Camunda database, before the send-request process will begin. Τherefore, it will be possible for the response to be correlated.