Map and Reduce task memory settings in Hadoop YARN

Question

In a map-reduce application on YARN is it necessary that the maximum memory of reducer task should be more than map task ?

Answer 1

It's preferable and generally, it is recommended that the reducer memory settings are higher than the mapper memory settings.

By default, both MapReduce.map.memory.mb and MapReduce.reduce.memory.mb are set to 1,024 MB