[YARN-335] Fair scheduler doesn't check whether rack needs containers before assigning to node

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0.2-alpha
• Component/s: scheduler
• Target Version/s: 2.0.3-alpha
• Assignee: Sandy Ryza
• Reporter: Sandy Ryza
• Created: 11/Jan/13 20:01
• Updated: 16/Jan/13 14:05
• Resolved: 15/Jan/13 16:41

Description

If an application has an outstanding request on a node, the fair scheduler may try to place a container on that node without checking whether that node's rack needs any containers. If the rack doesn't need any containers, none should be scheduled on the node.

This can cause an NPE in the fair scheduler.