Handling MQTT messages in WSO2 CEP 3.1.0

Question

I have a scenario in which I have MQTT publisher.

MQTT Client --> Message Broker --> WSO2 CEP (JMS input adaptor)

What are the ways by which I can get this published MQTT message as input to WSO2 CEP?

I tried using ActiveMQ as a message broker and a CEP JMS input adaptor listening to JMS message but ActiveMQ transforms MQTT message as ByteMessage, I believe CEP does not handles it as of now, as JMS messages published in the same setup is working fine.
I know WSO2 CEP 4.0.0 has a feature of MQTT input adaptor. How can I handle it in CEP 3.1.0?

Answer 1

Yes, We haven't handled the ByteMessage scenario for JMS input event adapter in CEP 3.1.0. But, we have fixed this in CEP 4.0.0 (and in CEP features which released with BAM 2.5.0)

I like to provide some options to make it work with CEP 3.1.0 .. As Tharik mentioned MQTT input event adapter feature is available from next CEP version (4.0.0). Below are the possible options.

1) You can either patch the JMS input event adpter and include that as a patch for CEP server. (Fix is available in [1])

2) Use the MQTT input event adapter jars which available in BAM 2.5.0. (Build the source [2] and copy the jar to dropins folder of CEP and follow [3])

3) Write your own custom MQTT input event adapter as given in [4]

[1] https://svn.wso2.org/repos/wso2/carbon/platform/branches/turing/components/event-stream/event-input-adaptor/org.wso2.carbon.event.input.adaptor.jms/1.0.2/src/main/java/org/wso2/carbon/event/input/adaptor/jms/internal/util/JMSMessageListener.java

[2] https://svn.wso2.org/repos/wso2/carbon/platform/branches/turing/components/event-stream/event-input-adaptor/org.wso2.carbon.event.input.adaptor.mqtt/1.0.0

[3] https://docs.wso2.com/display/BAM250/Input+MQTT+Event+Adapter

[4] https://mohanadarshan.wordpress.com/2014/07/14/writing-custom-event-adaptors-in-wso2-cep-3-1-0/

Thanks..

Answer 2

As you mentioned WSO2 CEP supports MQTT from version 4.0.0 onwards. You event cannot add WSO2 CEP 4.0.0 MQTT components/features to CEP 3.1.0 since input adapter architecture is different in new version.

I highly recommend to use CEP 4.0.0. If you really want this in CEP 3.1.0 you will have to write a custom event adapters for CEP 3.1.0. You can use refer new version source to get some idea but adapter implementation is different.