mapred.jobtracker.nodegroup.aware true Identify if jobtracker is aware of nodegroup layer. mapred.task.cache.levels 3 This is the max level of the task cache. For example, if the level is 2, the tasks cached are at the host level and at the rack level. mapred.jobtracker.jobSchedulable org.apache.hadoop.mapred.JobSchedulableWithNodeGroup The class responsible for an entity in FairScheduler that can launch tasks.