Difference between Flow, Sub Flow and Private Flow in Mule3

   Difference between Flow, Sub Flow and Private Flow   

    In Mule 3 we have three types of flow present:
    • Flow
    • Sub Flow
    • Private Flow
    Find a example of each flow in STUDIO Visual Editor :

    Find a example of each flow in XML Editor :

    All three Flow types can be referenced from a Flow Reference component.
  • Flow
    • Flow is a message processing block that has its own processing strategy and exception handling strategy.
    • Flow can Use in integration tasks, data processing, connecting applications, event processing etc.
  • Sub flow
    • Subflow always processes messages synchronously but inherits processing strategy and exception handling strategy from the calling flow.
    • Subflow can be used to split common logic and be reused by other flows.
  • Private flow
    • Processing strategy :
      • Sub-flow: It is always synchronous
      • Private-flow: Its behaviour depends on the processing strategy

    • Performance :
      • Sub-flow: It has a better performance when using request-response exchange pattern as they are actually a new processor chain injected in the flow at configuration time.
      • Private-flow: It is useful for asynchronous call, if we configured the processing strategy properly

    • Exception strategy :
      • Sub-flow: will use the exception strategy defined in the main flow and it will have the exception got in the sub-flow.
      • Private-flow: the exception will be trapped by the local exception strategy. The exception will not be propagated to that main flow.

    • Message Properties :
      • In both case all properties, regardless their scope, are preserved from the main flow.

    • Threading profile :
      • Sub-flow: will share the parent flow threading profile configuration
      • Private-flow: allows you to define a different threading profile, but if you don't they will use the default one, not inherit the invoking flow one.

    • Overall :
      • Sub-flow: Sub flow run within the same execution context (exception handler, transaction, properties) of its main flow.
      • Private-flow: Private flow will initiate a new execution context.

    • To summarize :
      • Sub flow is always recommended except in the case the exception needs to be handled in a separate flow different from the main flow or you are implementing an asynchronous pattern.

  • Code Reference

If you got some knowledge about Difference between flow, sub flow and private flow, please follow with me in next topic to understand about Flow Processing Strategies.

Comments