[FLINK-18034] Introduce PreferredLocationsRetriever

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.12.0
• Component/s: Runtime / Coordination
• Labels: pull-request-available
• Assignee: Zhu Zhu
• Reporter: Zhu Zhu
• Created: 29/May/20 10:02
• Updated: 11/Jun/20 03:45
• Resolved: 11/Jun/20 01:15

Description

Preferred locations based on state and inputs are scattered into multiple components, which makes it harder to reasoning the calculation and complicates those hosting components.

We can introduce a PreferredLocationsRetriever to be used by ExecutionSlotAllocator which returns preferred locations of an execution vertex and hides the details of the calculation from other components.

Issue Links

• links to: GitHub Pull Request #12423