Iguana Message Queue

The Catcher channel uses a To Channel component as a Destination to submit messages to the queue. The Sender channel uses the Catcher channel as a source and processes the messages queued by the Catcher. This means that we can use the Iguana log to resubmit messages to the Sender channel for reprocessing if needed.

Depending on our requirements we can use a Filter component in the Catcher or Sender. For this example we put our code in the Filter component of the Sender channel. This means that when we resubmit messages to the Sender channel the Filter code will be run again. If we used the Filter component of the Catcher channel then the Filter code would not be run for resubmissions. For this tutorial we want the Filter code to be run for resubmissions

If for any reason you did not want the Filter code to run when resubmitting messages, you could use the Filter component of the Catcher channel. An example scenario where you might want this behaviour would be if you needed to modify data in the Filter channel, but running the code a second time when a message was resubmitted would have the potential of introducing errors.