changing default scheduler in hadoop 1.2.1

Question

As FIFO has been default scheduler in hadoop 1.2.1, where exactly do i need to make changes to change default scheduler from FIFO to capacity or fair. I had recently checked mapred-default.xml which is present inside hadoop-core-1.2.1.jar as directed in this answer but i didnt get where to hit and change the scheduling criteria. Please provide guidance thanking in advance

I am a kind of beginner in hadoop so initially i didnt knew much about it. But as most of my work (college project) is been completed on 1.2.1 itself, i am in very need of changing scheduling method for this version only — Abhilash Desai

OneCricketeer OneCricketeer · Accepted Answer · 2016-04-22T18:35:35

where exactly do i need to make changes to change default scheduler from FIFO to capacity or fair

In the mapred-site.xml

Fair Scheduler

<property>
  <name>mapred.jobtracker.taskScheduler</name>
  <value>org.apache.hadoop.mapred.FairScheduler</value>
</property>

Capacity Scheduler

<property>
  <name>mapred.jobtracker.taskScheduler</name>
  <value>org.apache.hadoop.mapred.CapacityTaskScheduler</value>
</property>

Note, you may want to actually read the documentation from those links because they tell you how to set them up in detail.

changing default scheduler in hadoop 1.2.1

1 Answers