Workflow Guidance

Question

All workflow Gurus,
What is your opinion is the best way to
- learn the oracle workflow
- what reference/doc material you used to learn it
+ Workflow guide looks like a nightmare to read, hellish boring drool.
+ are there samples, preferrably guided practice which helps you to conquer this

Answer 1

Steve,
Thanks for the detailed feedback. It is unfortunately true we have a limitation in the Ed Centers of only one instance to work on per class, so we haven't been able to have a cross-system example. But we can definitely add more information about how Workflow uses AQ and debugging information. We can work on this in the next revision of the course. So thanks very much for your input.
To follow up on the other part of this thread - JMS is not my area of expertise, but I can offer a couple of suggestions as far as the agent listener. The listener should check whether there are any subscriptions registered against the event, and if yes, execute them. If the subscription is not getting executed successfully to send the event to the workflow process, then it's possible that either there was some mismatch in the subscription definition so that the listener did not pick it to execute, or the listener picked the subscription and tried to execute it but encountered an error.
First case - doublecheck the subscription definition (step 4 of the tutorial). The system needs to be the local system as defined in the Global Workflow Preferences page, the Source Type for a message coming off a queue needs to be External, the Event Filter needs to exactly match the event name in the event definition, and the subscription status needs to be Enabled. Also the event status needs to be Enabled in the event definition. If any of these properties don't match, the subscription wouldn't be executed.
If the listener dequeued the event and did not find any matching subscriptions at all, then it should treat it as an Unexpected event and launch the Default Event Error process, which should send a notification to the system administrator. So you might also check the Worklist for the system administrator and see if there is any such notification.
Second case - If the listener matched the subscription to the event but there was an error during subscription processing, then any processing done up to that point should be rolled back, and the message should be placed on the WF_ERROR queue. So you could check whether there is anything on WF_ERROR. It is also supposed to launch the Default Event Error process which would send an error notification to the system administrator, so as before, you could check the Worklist. At this point it may be trickier to find out why the subscription errored out, but a couple of things worth checking:
- In the subscription definition, the Rule Function in this case should be the WF_RULE.Default_Rule which sends the event to the specified workflow process.
- The workflow item type and process name should exactly match the internal names defined for them in the Workflow Builder.
- If the error notification to the system administrator says there was no activity in the workflow process waiting to receive the event, that sometimes means that the Receive event activity is not marked as a "Start" activity in the node properties in the Builder, which it needs to be in order to launch a new process instance.
Or else I have seen this error when the event key was accidentally reused. The event key is used as the item key for the process (unless a correlation ID is also specified in the event, which I don't think it is in this tutorial). So if the listener tries to launch the workflow process with the event key as the item key, and it finds there has already been a process instance with that item key, then it cannot start a new one since the item key must be unique. Then it will error out. So if that happens, the event would need to be published with a new event key.
You may have already checked these things but anyway I hope some of this information will be useful.