[MAPREDUCE-1974] FairScheduler can preempt the same task many times

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.21.0, 0.21.1, 0.22.0, 0.23.0
• Fix Version/s: 0.22.0
• Component/s: contrib/fair-share
• Hadoop Flags: Reviewed
• Assignee: Scott Chen
• Reporter: Scott Chen
• Created: 27/Jul/10 23:36
• Updated: 12/Dec/11 06:19
• Resolved: 04/Feb/11 22:57

Description

In FairScheduler.preemptTasks(), tasks are collected from JobInProgress.runningMapCache.
But tasks repeat multiple times in JobInProgress.runningMapCache (on rack, node and cluster).
This makes FairScheduler preempt the same task many times.