mapreduce.task.io.sort.mb 10 hadoop.security.authentication simple mapreduce.jobtracker.hosts.exclude.filename hosts.exclude mapreduce.jobtracker.retirejobs false mapred.child.java.opts -Xmx200m -Djava.net.preferIPv4Stack=true mapreduce.jobtracker.persist.jobstatus.active false mapreduce.task.local.output.class org.apache.hadoop.mapred.MROutputFiles