As mentioned in
NM memory and CPU configs
Currently these values are coming from the config of the NM, we should be able to obtain those values from the OS (ie, in the case of Linux from /proc/meminfo & /proc/cpuinfo). As this is highly OS dependent we should have an interface that obtains this information. In addition implementations of this interface should be able to specify a mem/cpu offset (amount of mem/cpu not to be avail as YARN resource), this would allow to reserve mem/cpu for the OS and other services outside of YARN containers.