[FLINK-19907] Channel state (upstream) can be restored after emission of new elements (watermarks)

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.12.0, 1.11.2
• Fix Version/s: 1.12.0, 1.11.3
• Component/s: Runtime / Network
• Labels: pull-request-available
• Assignee: Roman Khachatryan
• Reporter: Roman Khachatryan
• Created: 31/Oct/20 16:56
• Updated: 10/Nov/20 19:00
• Resolved: 03/Nov/20 12:12

Description

In StreamTask.beforeInvoke:

1. operatorChain.initializeStateAndOpenOperators(createStreamTaskStateInitializer());

2. readRecoveredChannelState();

 But operatorChain.initializeStateAndOpenOperators can emit watermarks (or potentially some other stream elements).

 I've encountered this issue while adding an EndOfRecovery marker - in some runs of in OverWindowITCase.testRowTimeBoundedPartitionedRangeOver the marker was emitted after the watermark.

 

cc: Zhijiang, Piotr Nowojski

Issue Links

• blocks: FLINK-19856 Add EndOfChannelRecovery rescaling epoch
• links to: GitHub Pull Request #13866
• links to: GitHub Pull Request #13881