[FLINK-4490] Decouple Slot and Instance

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.2.0
• Component/s: Runtime / Coordination
• Assignee: Stephan Ewen
• Reporter: Kurt Young
• Created: 25/Aug/16 14:34
• Updated: 19/Sep/16 20:02
• Resolved: 02/Sep/16 15:38

Description

Currently, Slot and Instance holds each other. For Instance holding Slot, it makes sense because it reflects how many resources it can provide and how many are using.

But it's not very necessary for Slot to hold Instance which it belongs to. It only needs to hold some connection information and gateway to talk to. Another downside for Slot holding Instance is that Instance actually contains some allocate/de-allocation logicals, it will be difficult if we want to do some allocation refactor without letting Slot noticed.

We should abstract the connection information of Instance to let Slot holds. (Actually we have InstanceConnectionInfo now, but lacks of instance's akka gateway, maybe we can just adding the akka gateway to the InstanceConnectionInfo)

Issue Links

• links to: GitHub Pull Request #2447