Understanding Various Mule Flows – Mulesoft Tutorial

In this mule ESB tutorial we will understand various mule flows in detail with downloadable examples.

There are 4 types of flows in mule. While creating these flows the flow name should be unique in whole mule project despite beaning in different mule application XML file.

1. Subflow always processes messages synchronously (relative to the flow that triggered its execution).
2. Subflow executes in the same thread of the calling process. Calling process triggers the sub-flow and waits for it to complete and resumes once the sub-flow has completed.
3. Subflow inherits processing strategy and exception handling strategy from the parent/calling flow.

Use – It can be used to split common logic and be reused by other flows.

Example:
Configuration – We have created 3 loggers in total, 2 in main/calling flow which is before and after flow reference and one in the sub flow.

Output:

Same as sub-flow, the only difference is that in synchronous flows you need to separately define an exception strategy to it, it does not inherit the exception strategy of its calling flow.

Example:


Output:

1. As in sub-flow and synchronous flow, calling process triggers the sub-flow or synchronous flow and waits for it to complete; for asynchronous flow the flow, calling process triggers an asynchronous flow and moves ahead to its next activity.
2. An asynchronous flow executes in parallel to its calling/parent flow in a different thread.
3. An asynchronous flow does not return its output it its parent/calling flow.

Example:
Configuration –
1. We have created 4 loggers in total, 2 in main/calling flow which is before and after flow reference (inside Async flow calling a sub-flow) and one in the sub flow.
Since sub-flow inherits processing strategy and exception handling strategy from the parent/calling flow, the sub flow will execute asynchronously.

2. We have added a groovy script in the subflow to pause the thread executing it for 10 sec.

Output:

Flow that does not have an inbound connector in the source. Means a private flow cannot start of its own on receiving the inbound message as it does not have any inbound connector, A private flow can only be called using flow-ref same as sub-flow.

Example: