Designer 10.7 | webMethods Service Development Help | Working with MQTT Triggers | MQTT Trigger Requirements
 
MQTT Trigger Requirements
For an MQTT trigger to be saved in an enabled state, the following must be true:
*The MQTT connection alias that you want to use to create subscriptions and receive messages must exist.on the same Integration Server
*The trigger service that you want to use to process messages received by the trigger must exist on the same Integration Server.
*The MQTT trigger must specify a topic.
When you save an MQTT trigger, Designer verifies if the MQTT trigger meets the preceding requirements. If it does not, Designer will prompt you to cancel saving the trigger or save the MQTT trigger in a disabled state.