Allocation of Datanode Memory and Nodemanger memory - Clarification Newbie

[#1]

I am newbie to Cloudera Hadoop . Working on Mapreduce program.

I would like to increase the datanode memory ,  nodemanager memory ,

Should I have to increase in the hadoop-env.sh and Yarn-site.xml in the below tags 

I have been allocated around 128GB of RAM in my slave nodes.

So is there any base line to start with - more of a crap shot. My program is indeed a  heavy computation.

if I want to increase the datanode memory should i have to the put the numbers inside  HADOOP_DATANODE_OPTS  ? or is there any other tags ? please help me on this. 

yarn.nodemanager.resource.memory-mb
yarn.app.mapreduce.am.resource.mb
mapreduce.map.memory.mb
mapreduce.reduce.memory.mb	

any information is highly appreciable.

Thanks

[#2]

@matt123

You can refer this link

https://community.cloudera.com/t5/Hadoop-101-Training-Quickstart/Map-and-Reduce-Error-Java-heap-spac...

[#3]

@saranvisa

Thanks for the response . Read your thread . In that post everything is pertain to Mapreduce . 

we have 128 GB allocated for Slave nodes. 

Could you please let me know what should go inside the base number to start with. 

yarn.nodemanager.resource.memory-mb

we have 2  hexa cores  runining . please let me know if this correct 

yarn.nodemanager.resource.cpu-vcores = 12 
yarn.scheduler.minimum-allocation-vcores =	1
yarn-scheduler.maximum-allocation-vcores =  10

what should go inside 

yarn.scheduler.minimum-allocation-mb	
yarn.scheduler.maximum-allocation-mb

[#4]

Take a look here, it gives some good calcs to reach a baseline for the YARN/MR memory settings. Cores are straightforward leave a core or two for the other process and the rest to YARN containers.

All of these changes should be done through CM, if not using CM then in the yarn-site.xml and mapred-site.xml.

http://docs.hortonworks.com/HDPDocuments/HDP2/HDP-2.4.3/bk_installing_manually_book/content/determin...

[#5]

Here is one of our Community Knowledge articles that may also be of assistance when calculating memory size.

Selecting the Right Hardware for Your New Hadoop Cluster