[FLINK-11148] Rescaling operator regression in Flink 1.7

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Duplicate
• Affects Version/s: 1.7.0
• Component/s: Runtime / Coordination
• Assignee: Unassigned
• Reporter: Truong Duc Kien
• Created: 13/Dec/18 09:37
• Updated: 31/Jul/20 10:14
• Resolved: 31/Jul/20 10:14

Description

We have a job using 20 TaskManager with 3 slot each.

Using Flink 1.4, when we rescale a data stream from 60 to 20, each TaskManager will only have one downstream slot, that receives the data from 3 upstream slots in the same TaskManager.

Using Flink 1.7, this behaviour no longer hold true, multiple downstream slots are being assigned to the same TaskManager. This change is causing imbalance in our TaskManager load.

Issue Links

• duplicates: FLINK-12122 Spread out tasks evenly across all available registered TaskManagers