[HADOOP-4683] Move the call to getMapCompletionEvents in ReduceTask.ReduceCopier.fetchOutputs to a separate thread

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.20.0
• Hadoop Flags: Reviewed
• Assignee: Jothi Padmanabhan
• Reporter: Devaraj Das
• Created: 19/Nov/08 15:56
• Updated: 08/Jul/09 16:53
• Resolved: 12/Dec/08 08:00

Description

The method ReduceTask.ReduceCopier.fetchOutputs makes a call to getMapCompletionEvents every iteration of the loop. This should be moved out to a separate thread. This might slow down the shuffle scheduler in some cases since there is a sleep inside the getMapCompletionEvents method.