[MAPREDUCE-3126] mr job stuck because reducers using all slots and mapper isn't scheduled

• Type: Bug
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 0.23.0
• Fix Version/s: 0.23.0
• Component/s: mrv2
• Target Version/s: 0.23.0
• Assignee: Arun Murthy
• Reporter: Thomas Graves
• Created: 29/Sep/11 22:52
• Updated: 15/Nov/11 00:48
• Resolved: 11/Oct/11 18:25

Description

The command in MAPREDUCE-3124 run and this job got hung with 1 Map task waiting for resources and 7 Reducers running (2 waiting). The mapper got scheduler, then AM scheduled the reducers, the map task failed and tried to start a new attempt but reducers were using all the slots.

I will try to add some more info from the logs.