Instance retrieval after BPM failure

Question

Hi,
Suppose if BPM fails after an instance is created and in-flight.
Can that in-flight instance be retrieved after BPM recovers from a failure? Is there any kind of procedure to recover it or is it auto-retrieved? Is the instance info and details in the BPM internal database? Can we see this in the audit trail?

Answer 1

Yes - once the instance has been created, you'd want to handle both sytem and business exceptions inside the process.
Once inside the process if a system exception is not handled, it is retried the number of times the Engine's setting calls for at the interval specified by another of Engine's settings. The default Engine properties are to have Studio retry one time at a 15 second interval and Enterprise retry 5 time at 30 minute intervals. If a system exception is not caught, it is either propagated back to the parent process or (if there is no parent process) it is sent to the End activity. This is why you almost always want every process to built with an Exception handler that handles the "Others" exception coming out of it at a minimum. If you do not do this, during testing you'll notice that you have work item instances that seem to disappear. In reality, there was an exception that was not caught.
Others will probably disagree, but compensations aren't that common. If an exception occurs inside an activity, you can either catch it inside the logic using a try/catch block or allow it be caught by the Exception Handler. If caught by the Exception Handler, then the original activity's transaction never committed and there's no need for a compensation or rollback.
Dan