​How does ambari adjust the amount of physical memory available to YARN for a node in cluster?

[#1]

How does ambari adjust the amount of physical memory available to YARN for a node in cluster?

[#2]

@shi cheng

Why would Ambari adjust physical memory assigned to YARN? You configure YARN memory (capacity scheduler settings) through Ambari - YARN config page. Please see usage below:

https://hortonworks.com/hadoop-tutorial/configuring-yarn-capacity-scheduler-ambari/#configure-schedu...

Ambari's own memory is configured using /var/lib/ambari-server/ambari-env.sh and changing the value of -Xmx<heap size you want>