This stage is in studying the exception in the theory of workflow, and sharing your experience with everyone, and I hope everyone can more valuable comments.
1, the exception in the workflow is unable to wait for the error, the exception is only the process outside the normal process, and it is not necessarily a mistake, and in some cases, especially the process is inseparable. When the wrong direction is performed, we want the system to throw an exception, so that the system returns to normal processes through an abnormal processor and recovery mechanism.
2. Exceptions can be divided into exceptions and unforeseen exceptions. For the former one, we can solve them by the design process analysis, establish an exception model, and automatic processing of specific exceptions via the ECA (Event-Condition-Action) rule when implementing. For the latter, it is more troublesome, and the settings directly send it directly to the user interactively to choose how to handle it in some workflow management systems.
3. There are two levels for abnormal processing, one is the processing of the task level, the other is the workflow level.
4. At the task level we can use retry, set a copy, set the restore point three ways, but we should see that the implementation of these three ways has certain difficulties. Take a copy as an example. There are different copies, which will cause waste on resources, and we have to assign certain resources to ensure its normal operations for each copy. Second, because it is a copy, the completion of this process is based on any of the completed as a standard, then if one of them is complete, the other processes should be suspended, otherwise there will be problems, and when it is suspended, it will definitely An additional exception is generated, and this time involves the recovery of resources. This will also be a difficult problem. Again, create a copy, then the number of objective processes increases, then does the chance to generate an error not increase?
From this point of view, there are many problems worth studying for abnormal processing.
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