You can do this by sending a error json in the reply message payload and setting status to 0.
POST /api/beta/tenants/57352d50-9cb3-11e5-b6ff-404014d5dd81/clients/7a7316b0-9cb3-11e5-b6ff-404014d5dd81/messages { "id":1000, "type":"p2p", "payload": { "error_code": 1, "error_msg": "The server timed out while processing message.", }, "qos":1, "duplicate":0, "save":1, "status":0 }
You can agree to a set of error_code and error_msg between your client app and your IoT app. These error code and error message would be part of the Result object passed to your pointToPointMessageHandler.
Thanks its working now.
Henry
I am using point to point message on one of my IoT device. My app sends a point to point message to the Client and the Client responds back with a Reply. On receiving the reply my App does some background processing. This works fine but i want to inform the Client of the processing failing with an error message.