[FLINK-19377] EventTimeWindowCheckpointingITCase setup can hide problems when changing parameters

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.8.3, 1.9.3, 1.10.2, 1.11.2
• Fix Version/s: 1.12.0
• Component/s: API / DataStream, Tests
• Assignee: Aljoscha Krettek
• Reporter: Aljoscha Krettek
• Created: 23/Sep/20 09:33
• Updated: 22/Jun/21 13:55
• Resolved: 25/Sep/20 12:26

Description

I noticed this while debugging EventTimeWindowCheckpointingITCase. If you change testSlidingWindows() to use a tumbling window instead of the sliding window the test should fail. Interestingly, the tests only fail when using the RocksDB backend but not for the heap-based backends.

You can follow the flow by setting a breakpoint on the AssertionError being thrown in ValidatingSink. Somewhere in the Task innards it will be suppressed/swallowed and the test will succeed.