[MAPREDUCE-4849] TaskSelector not used in FairScheduler

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 1.0.4, 1.1.1
• Component/s: contrib/fair-share
• Labels: documentation
• Assignee: Unassigned
• Reporter: Vincent Behar
• Created: 05/Dec/12 13:43
• Updated: 05/Dec/12 13:43

Description

The documentation (http://hadoop.apache.org/docs/r1.0.4/fair_scheduler.html) describes the mapred.fairscheduler.taskselector parameter as an "extension point", but while the FairScheduler does instantiate the custom TaskSelector provided this way, it does not call any of its methods (obtainNewMapTask, obtainNewReduceTask, neededSpeculativeMaps or neededSpeculativeReduces).

We should either update the FairScheduler to use the TaskSelector when scheduling a task, or completely remove the TaskSelector and update the documentation.