[FLINK-24807] Fix the issues in checkpoints with iteration

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.1.0
• Fix Version/s: ml-2.0.0
• Component/s: Library / Machine Learning
• Labels: pull-request-available
• Assignee: Yun Gao
• Reporter: Yun Gao
• Created: 06/Nov/21 04:08
• Updated: 15/Dec/21 03:11
• Resolved: 10/Nov/21 15:57

Description

We have met some more issues in supporting checkpoints with iteration:

1. Support snapshotting Replayer Operator and per-round wrapper.
2. Fix the issues that after head tasks finished, the coordinator continues emitting CoordinatorCheckpointEvent, which made the checkpoint fails due to events not sending.
3. Support raw operator state inside the iteration. 

Issue Links

• links to: GitHub Pull Request #25