[YARN-4125] In addition to aggregate availability for an app, headroom should provide information on largest container that can be allcoated

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 2.7.1
• Component/s: scheduler
• Assignee: Unassigned
• Reporter: Karthik Kambatla
• Created: 08/Sep/15 02:48
• Updated: 08/Sep/15 03:06

Description

Today, headroom is an indicator to an application on the resources available to it. It is an aggregate across all nodes. If all the nodes have either only memory or only cpu available, no container can be allocated. The headroom should hint at this too, so apps can make decisions sooner. MAPREDUCE-6470 is a case of this, and has an example for the curious.

May be, we should add an API that returns both aggregate headroom and large container allocatable.

Issue Links

• relates to: MAPREDUCE-6470 ApplicationMaster may fail to preempt Reduce task