BPMN process starting with a message -- channel name

[gruby_karol]

I have a small project to play around with Kogito and educate myself along the way: https://github.com/karol-brejna-i/kogito-mqtt-decision-process-kafka/tree/mqtt-only (please, note 'mqtt-only' branch).

In my project, I want to start a process every time an MQTT message is received on a specific topic. 

This did not work out of the box. MQTT sends byte[] (not Strings) and I got some errors.

I walked around the problem by defining the process like this: 

And adding a simple "bridge" that reads the messages from MQTT,  converts and sends them to a channel defined in the process (represented by 'moves' element in the diagram above):

public class Brydzia {

    private static final Logger LOG = Logger.getLogger(Brydzia.class);

    @Incoming("source")

    @Outgoing("kogito_incoming_stream")

    public String deserialize(byte[] payload) {

        return new String(payload);

    }

}

(see: https://github.com/karol-brejna-i/kogito-mqtt-decision-process-kafka/blob/mqtt-only/src/main/java/org/demo/rsotf/Brydzia.java)

Please, note "kogito_incoming_stream" which seems to be the name assumed for a channel used in the BPMN process.

This works like a charm. Or, worked like a charm until version 1.11.

Today I upgraded Quarkus and Kogito and I see some problems.

I see that it works as previously up to Quarkus 2.2.2.Final which comes with Kogito 1.10.0Final.

The next version (2.2.3.Final) brings Kogito 1.11.1.Final and the application stops working

2021-10-07 14:50:48,240 WARN  [io.sma.rea.mes.provider] (Quarkus Main Thread) SRMSG00207: Some components are not connected to either downstream consumers or upstream producers:

        - ProcessingMethod{method:'org.demo.rsotf.Brydzia#deserialize', incoming:'source', outgoing:'kogito_incoming_stream'} has no downstream

I assume the "hardcoded" name for the process channel had changed.

So, I have the questions:

1. What is the new name for the channel?

2. Is there a more elegant way to send a message to a channel that initiates a process?

Regards,

Karol

[gruby_karol]

Anyone?

[Francisco Javier Tirado Sarti]

Hi,

Take a look to this blog https://blog.kie.org/2021/09/kogito-process-eventing-add-ons.html. There I try to explain how this is supposed to work

I think you can now skip Brydzia class and just add to your application.properties

mp.messaging.incoming.moves.connector=smallrye-kafka mp.messaging.incoming.moves.value.deserializer=org.apache.kafka.common.serialization.StringDeserializer

mp.messaging.incoming.moves.topic=source

Your byte[] should be converted to String automatically out of the box.

If that still does not work, you can keep Brydzia and define

mp.messaging.incoming.moves.connector=kogito_incoming_stream mp.messaging.incoming.moves.value.deserializer=org.apache.kafka.common.serialization.StringDeserializer

[Francisco Javier Tirado Sarti]

I make a mistake at the end of the previous e-mail

If you decide to keep Brydzia in the middle,  you need

mp.messaging.incoming.kogito_incoming_stream.connector=smallrye-kafka

mp.messaging.incoming.kogito_incoming_stream.value.deserializer=org.apache.kafka.common.serialization.StringDeserializer