Yes... it doesn't make sense... I bumped into the same question, and the default of "yarn.scheduler.maximum-allocation-vcores" is actually 4 in the code.  I fired a JIRA for this. https://issues.apache.org/jira/browse/YARN-4499 ... View more

Thank you, mfox. My problem was that the basic install set all of HDFS's groups to "superuser" instead of "hadoop". Changing it to "hadoop" allowed mapreduce to write its history logs to the correct location. ... View more