Can Hadoop Fair/Capacity Scheduler be used on MR1?

Question

From what I have read, YARN (MRv2) allows a way to plug in a scheduler, replacing the default FIFO scheduler. My question is, can we do the same in MRv1? Is there a way to replace the FIFO scheduler in the older version of Hadoop, or is this something that is provided only with YARN?

Answer 1

I've been using the fair scheduler for some time now in the 0.20.x version of Hadoop and never had any issues.

You can set the following property:

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

And you can then go to http://<jobtracker URL>/scheduler

More details on how to setup for example fair scheduler in MR1 here.