About Mule Flow Design (Design Center)
In Design Center, you create a Mule application in a project having one or more flows. A flow typically consists of one trigger and one or more modules or APIs. First, you choose and configure a trigger for a flow.
Next, you click Plus to select the next component.
When you run an app, a worker space is created, but not always instantaneously. When the worker space is ready, a green bar in each part of the flow indicates data flow is working fine. A red bar indicates a problem.
When you execute the Mule app, data moves through a flow from left to right. Information about the data appears on each part of the flow:
Component icon and name
Operation name in bold
Elements that can make up the Mule Event: payload, attributes, and vars (variables).
The state of the elements: created (+), deleted (-), edited (triangle) or unchanged.
You can use these indicators to debug apps by sending mock requests to start the apps in the case of an HTTP-triggered app at interim stages of the design. In the case of a scheduler-triggered app, you can force a rerun of the app by clicking Run, or wait until elapsed time triggers the app. An indispensible indicator for debugging is the log data that you can view by expanding Log at the bottom of the canvas.