[FLINK-2646] User functions should be able to differentiate between successful close and erroneous close

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Staged
• Affects Version/s: 0.10.0
• Component/s: API / DataStream
• Labels: usability
• Assignee: Unassigned
• Reporter: Stephan Ewen
• Created: 09/Sep/15 15:14
• Updated: 17/Apr/21 11:54
• Resolved: 17/Apr/21 11:54

Description

Right now, the close() method of rich functions is invoked in case of proper completion, and in case of canceling in case of error (to allow for cleanup).

In certain cases, the user function needs to know why it is closed, whether the task completed in a regular fashion, or was canceled/failed.

I suggest to add a method closeAfterFailure() to the RichFunction. By default, this method calls close(). The runtime is the changed to call close() as part of the regular execution and closeAfterFailure() in case of an irregular exit.

Because by default all cases call close() the change would not be API breaking.