While looking into MAPREDUCE-5207 (adding defaults for
mapreduce.{map|reduce}.memory.mb), I was wondering how much headroom
should be left on top of mapred.child.java.opts (or other similar JVM opts) for
the container memory itself?I would like to have separated java option settings for map/reduce parts. Something like mapred.map.child.java.opts mapred.reduce.child.java.opts.
