Label-based Scheduling for MRv1 Jobs

This document describes how to use label-based scheduling for MapReduce (MRv1) jobs.

You can run jobs on specified nodes or groups of nodes using label-based scheduling – assigning labels to various groups of nodes and then using the labels to specify where jobs run. This feature is used in conjunction with the Fair Scheduler. The labels are mapped to nodes using the node labels file, a file stored in MapR-FS. When you run jobs, you can place them on specified nodes individually or at the queue level.

Warning:

When using label-based job placement, you cannot use the Fair Scheduler with preemption or task prefetch. For details on prefetch, see parameter mapreduce.tasktracker.prefetch.maptasks on page mapred-site.xml (MapReduce v1).