Step 7: MapReduce configuration
You can increase the memory allocation for the ApplicationMaster, map tasks, and reduce tasks.
The minimum vcore allocation for any task is always 1. The Spill/Sort memory allocation of 400 should be sufficient, and should be (rarely) increased if you determine that frequent spills to disk are hurting job performance.
common MapReduce parameters
yarn.app.mapreduce.am.command-opts are configured for you automatically based
on the Heap to Container Size