[FLINK-21839] SinkFunction snapshotState don't snapshot all data when trigger a stop-with-drain savepoint

• Type: Bug
• Status: Closed
• Priority: Critical
• Resolution: Not A Problem
• Affects Version/s: 1.12.2
• Component/s: Runtime / Checkpointing
• Assignee: Yuan Mei
• Reporter: Darcy Lin
• Created: 17/Mar/21 05:18
• Updated: 14/Apr/21 09:46
• Resolved: 14/Apr/21 09:46

Description

This problem was discovered when I was developing the flink code. In my flink code, my custom sink don't send all data that be produced by event_time window when trigger stop-with-drain savepoint .

TestSink.java is a example that SinkFunction invoke() continues to run after snapshotState() executed when trigger a stop-with-drain savepoint by rest api.

//TaskSink.java log
sink open
invoke: 0
invoke: 1
invoke: 2
invoke: 3
invoke: 4
invoke: 5
invoke: 6
invoke: 7
invoke: 8
invoke: 9
...
invoke: 425
invoke: 426
invoke: 427
snapshotState
invoke: 428 // It should be executed before snapshotState.
sink close

Issue Links

• is related to: FLINK-2491 Support Checkpoints After Tasks Finished